TFMx IR Detector Photomodules on typenumber/O-R/PHOTOMOD.pdf · Free-Space Data Transmission in the Near Infrared Data transmission in free space places a high interference immunity

TELEFUNKEN Semiconductors06.96

TFMx IR Detector Photomodules

TELEFUNKEN Semiconductors06.96

Table of Contents

General Information...................................................................................................................... 1Introduction.................................................................................................................................. 1Available Types and Packages..................................................................................................... 2TEMIC Type Designation Code .................................................................................................. 4

Free-Space Data Transmission in the Near Infrared ................................................................. 5Optical Sources of Interference.................................................................................................... 5Various Radiation Sources in Filtered Silicon Detector Diodes.................................................. 5Application Hints ......................................................................................................................... 8

Transmission Range....................................................................................................................... 9

The Languages of Data Transmission Systems......................................................................... 12The RC 5 Code........................................................................................................................... 12The RECS 80 Code .................................................................................................................... 14The NEC Code ........................................................................................................................... 16

Description of the Detector Photomodules TFM Series ........................................................... 17Functional Description............................................................................................................... 17

Behavior Under Operational Conditions.............................................................................. 19Properties and Applications ....................................................................................................... 19

Different Telegram Conditions............................................................................................. 19Influence of the Integrator .................................................................................................... 20

Features and Restrictions of the Various Components in the TFM Series ............................ 21Working Conditions ................................................................................................................... 22

Measurement Procedure and Test Circuit ............................................................................ 22Sensitivity in Dark Ambient................................................................................................. 22Disturbing Optical Radiation................................................................................................ 23Behavior in Electromagnetic Fields ..................................................................................... 23Influence of Disturbed VS.................................................................................................... 24Sensitivity ............................................................................................................................. 24

Typical Circuitry ........................................................................................................................ 24Typical Application Circuit.................................................................................................. 24Recommendations for Evaluation ........................................................................................ 25

Appendix ..................................................................................................................................... 26Comparison Test ........................................................................................................................ 26Summary .................................................................................................................................... 26Plastic Suppliers......................................................................................................................... 26

Package Dimensions.....................................................................................................................27

Data Sheets....................................................................................................................................31

TELEFUNKEN Semiconductors 106.96

General Information

IntroductionInfrared remote controls have become a stan-dard part of home entertainment equipment.Nearly all functions of sat receivers, TV sets,VCRs, hi-fi audio receivers and compact diskplayers are remote-controlled.

Without exception, the signals have beentransmitted up until now with an optical carrierin the near infrared with a wavelength between840 nm and 960 nm. Infrared headphones,interpreter transmission systems in conferencerooms, optical computer links and optoelec-tronic keys also work in this wavelength range.

Remote control receivers must be extremelysensitive and should not react to interferencefrom other infrared emitters. The systems mustalso not disturb each other.

Generally, interference between remote controlsystems can be avoided by addressing the dif-ferent units with a special code. The aim is tointegrate the control of different units into one.

For the developer of remote control systems, itis an essential task to avoid interference byomni-present optical and electromagneticradiation sources. Therefore, certain specifica-tions must be made for the receiver photo-module and with regards to their properties inthe application.

The system developer has a substantial influ-ence on the performance of the system bychoosing a suitable transmission code. Theprocedure in evaluating all incoming signals(either disturbing or useful ones) contributessignificantly to the optimization of the system.

This application note gives some necessarybackground information for the system devel-oper to optimize the operation of photomod-ules. The physical boundary conditions which

can have an influence on the performance ofthe receiver photomodules are also described.

The IR remote control photomodules withinthis design guide are complete front ends,including photo pin diode, AGC amplifier,bandpass and demodulator.

TEMIC offers the safety of a perfectedproduct. The components are based on themany years' experience of Europe's numberone producer of infrared receivers.

Typical applications

• TV sets

• Video recorders

• Sat receivers

• Slide projectors

• Hi-fi components

• Data communication

Special features

• Compact outline

• Available for carrier frequencies of 27 kHzup to 62 kHz

• No external components necessary

• Output microcomputer-compatible

• High sensitivity for large transmitting range(120 ft/ 35 m)

• Maximum interference safety against opti-cal and electrical disturbances

• High quality level ISO 9001

• Automated large-volume production

2 TELEFUNKEN Semiconductors06.96

Available Types and Packages

TFMS – standard side view

TFMY – top view with transparent holderand light guide

TFMX – side view with holder

TFMT – standard top view

TFMW

TFMU – top view with very flat holder


TFMK – side view with holder

TFMC – top view with flat holder

TFMM – SMD case

TFM Type Series Typical Application Application Examples

TFM.1..0 Short bursts and high duty cycles Continuous data transmission;RECS 80 code

TFM.1..0T Short bursts and low duty cycles RECS 80 code

TFM.2..0 Long bursts and low duty cycles

TFM.5..0 Standard type suitable for most transmission codes RC 5 code;NEC code

TFM.7..0 Standard type suitable for most transmission codesReduced sensitivity (small PIN diode)

RC 5 code;NEC code

For more details on the features and limitations of the type series please see later in the text.


TEMIC Type Designation Code

The key to understanding the type name is shown in the following graph.

TFM

Characters for various lengths andbending of leads or tinplated leads

One digit for output polarity(0:standard, 9 active high output)

Two digits for the carrier frequencye.g., 30, 33, 36, 37, 38, 40, 56 kHz

One digit for the TFM series

One character for package

Last character: A, B, C, D, E, F, G, H, I, ... = Different mechanical dimensions of the lead (see pages 27-34)

SN = Tin-plated leadT = TFM series for low duty cycle and

short bursts

Example: TFMS5360SN = Standard receiver with 36 kHz center frequency, active low output, side view package and with tinplated leads


Free-Space Data Transmission in the Near InfraredData transmission in free space places a highinterference immunity on the photomodules.The receiver unit (waiting to receive signals) isloaded with different optical and electromag-netic disturbances, omni-present in the ambientor generated by the electrical appliance itself.All optical sources with an emission spectrumin the receiving bandwidth (830 nm - 1100 nm)of the detector can be considered as disturbingsources. Possible sources for electrical inter-ferences are all modulated power signals in theoperating frequency range as found especiallyin deflecting currents in TV sets with theirharmonics. Another potential source for dis-turbances are energy-saving fluorescent lamps.

Optical Sources of InterferenceIn the visible, remote control receivers aretotally insensitive because they are equippedwith an optical cut-off filter at a wavelength ofe.g., 830 nm. Therefore, only radiation withlonger wavelengths are detected. Specialmeasures in the design and technology ofTEMIC devices ensure that sensitivity above950 nm drops as sharply as possible.

The silicon photo detector receives in this waya limited spectrum originating from the com-mon broad band "white" light sources whichare emitted in the visible and infrared, respec-tively. For the assessment of visible radiation,mostly the quantity illuminance (measured inLux = Lumen/ m2) instead of the quantityirradiance (measured in Watt/ m2) is used.However, the quantity illuminance is abso-lutely unsuitable for the description of infraredradiation because the part of radiation withwavelengths longer than 780 nm is generallynot assessed. This will be described later moredetailed.

Generally, the question of the photo currentgenerated in a remote control receiver by adefined illumination arises. This can not be

answered without knowing the spectral distri-bution of the source.

Various Radiation Sources inFiltered Silicon Detector DiodesThe spectral distribution of a radiant source isvery varied and is dependent on the mecha-nism of radiation generation. The spectralemission curve of a thermal radiator such ase.g. an incandescent (tungsten) lamp is verybroadband and is described very well byPlanck's radiation law.

The spectral emission of fluorescent lamps israther complicated. In the infrared only, littleradiation is emitted. The spectral emission is acombination of the relative broadband emis-sion of the luminescent phosphor, the emittedmercury lines and the lines emitted from thegas filling the tubes. For assessment of thedisturbing influences of these sources, consid-eration has to be given to the various timeconstants (milliseconds) of the activated lumi-nescent materials. Direct emission on the otherhand is modulated to the current, passingthrough the lamp with all high frequency partson it. Therefore, one part of the emitted spec-trum is to be considered as a low-frequencysource while the other must be regarded as abroadband disturbing source with high fre-quency parts.

In the main, the sun can be seen as a thermalradiator which is influenced by atmosphericabsorption.

Silicon photo diodes with integrated cut-offfilters are used in IR data transmission systemssuch as the remote control appliance. Thespectral responsitivity of the diode in thereceived band is near 100% quantum effi-ciency. For the lower wavelength cut-off, theedge is at about 820 nm to 900 nm dependingon the wavelength of the emitters. The longwavelength cut-off and wavelength dependent


decrease of the sensitivity at longer wave-lengths is given by the spectral absorption ofthe silicon and the thickness of the activevolume (in pin diodes the wafer thickness).The response to different light sources can benumerically calculated with this kind of detec-tor model. For the calculation, a thermal radia-tor with a temperature of 5900 K was chosenas an equivalent to the solar spectrum (see fig-ure 1) for direct and global radiation underAM2 conditions.

This radiator is compared with a standardilluminant A radiator (T = 2856 K) which isapproximately equivalent to a common tung-sten incandescent lamp. In figure 2, the spec-tral density of the emission of both sources areshown as a function of the wavelength

normalized to equal photometrically weightedoutputs. Additionally, the sensitivity of thehuman eye V(λ) and of a filtered silicon detec-tor (similar to TEMIC BPV23NF) is shown. Itcan easily be seen that the radiation from thesun-equivalent source contains much lessradiation than the tungsten lamp in the sensi-tive wavelength range of the silicon detectordiode.

These facts can also be numerically evaluatedwith regard to the expected photo current ofthe detector diode resulting in the data given intable 1. The irradiance and illuminance neces-sary to generate a photo current Ira = 100 µAare listed for the filtered silicon detector diodewith an effective area of 8 mm2.

Wavelength [nm]

Spectral density of the irradiance [W/(m² µm)]

0

200

400

600

800

1000

1200

1400

1600

250 350 450 550 650 750 850 950 1050 1150 1250

AM2.0, Turb. = 0.1, dir AM2, T = 0.1, global

Figure 1. Spectral distribution of solar spectrum


Of course an irradiance could be assigned tothe thermal radiation. However, this is not veryeffective in our consideration because it cannotdescribe a result in terms of e.g. a photo cur-rent (the total irradiance is the integratedquantity over the wavelength from zero toinfinity). The illuminance resulting from theradiation of an infrared emitter is per definitionzero. The result is of significance in that dras-tically different illuminances of radiationsources are necessary for the generation ofequal photo currents. The efficiency of thesunlight as a disturbing source (photometri-cally weighted, same illuminance) is a factor of6 smaller than that of an incandescent lamp. Inthis calculation, the atmospheric absorption ofwater is not taken into account (see figure 1 –AM2 is equivalent to the solar irradiance onlate afternoon. Vertical axis: Spectral densityof the irradiance as a function of the wave-length.). This additional damping is increasedwith decreased azimuth. This should be con-sidered when calculating the photo currents ofdetectors in the ambient as e.g. remote controldetectors in cars. An equivalent mathematicalcorrect weighting of the real sunlight (seefigure 2) is mathematically no problem but it

makes no sense because its spectral distri-bution changes during the day and is depen-dent on weather conditions.

Weighting is carried out by the human eye[function V/(λ)] and by a filtered silicon detec-tor. The amplitudes are normalized to give,photometrically weighted, the same illumi-nance. The human eye will see both sources asequal 'brightness'.

Table 1. Filtered silicon detector diode (area A = 8 mm2, sensitivity equivalent to fig-ure 2)

Source Wave-length

Irradi-ance

Illumi-nance

IRED 950 nm 18 W/ m2 -

Thermalradiator

T = 5900 Kequivalent to

sun

– 14700 Lux

Thermalradiator

T = 2856 Kstandard

illuminant A

– 2500 Lux

The necessary irradiation or illumination togenerate a photo current of Ira is 100 µA.

Wavelength [nm]

Normal irradiation/ sensitivity

0

0.5

1

1.5

2

2.5

3

200 300 400 500 600 700 800 900 1000 1100 1200

T = 2856 K (A)T = 5900 K (sun)

V (lambda)BPV23 - Si-Detector

Figure 2. Blackbody radiation with various color temperatures


Application HintsIn this sub-chapter, recommendations for thedesign of a front panel for, e.g., a TV or a VCRdevice is given.

Usually, the front panels of home devices areblack and the optical window in front of the IRreceiver should also be black. That means thata plastic material is needed which istransmissive for the infrared signals but nottransparent for visible light. The diagram inFigure 3 shows an example of the spectraltransmittance of such a plastic material (BayerMakrolon color 45/601).

The cut-off wavelength should be between 700and 850 nm in order to appear black and inorder not to absorb signal energy.

There is a loss of power in every front panel ofabout 8% due to reflection (4% at each side).On the one hand, the thickness of the panelshould kept small, as there is an additional lossof energy in the plastic material. On the otherhand, the thickness of the plastic or the colormixture should not be too small in order toavoid that one can see inside the device. Incontrast to other products which have a metal

can shielding, the TEMIC TFM receiver has anadvantageous black package which preventsthat it is visible behind the front panel.

The relation between the necessary thicknessand the optical transmittance is given by:

τ(λ) = (1 - ρ) × e[ ( ) ]− ×α λ d

τ (λ) = Spectral transmittanceρ = Constant factor for reflection loss

(about 0.08)e = 2.718282α(λ) = Coefficient of plastic material

(about 0.03 mm-1 at 950 nm in the example above)

d = Thickness of front panel

There are several plastic materials with such aspectral behavior. Some examples of Polycar-bonate are given here:

Makrolon 2805; color #: 45-601(blue - black); supplier: Bayer

Makrolon 2805: color #: 45-401(green - black); supplier: Bayer

Lexan 21125, 21051, 21127;supplier: General Electric

Supplier's addresses: see appendix

Wavelength [nm]

0

10

20

30

40

50

60

70

80

90

100

400 500 600 700 800 900 1000 1100 1200

Spectral transmittance

Spectral sensitivity of the TFM module

Spectral transmittance/ sensitivity [%]

Figure 3. Spectral transmittance and spectral sensitivity of TFM modules


Transmission Range

The transmission range in free-space trans-mission systems is defined by a series of dif-ferent parameters. Fundamental data are theproperties of the transmitter and receiver units.Additionally, the ambient can influence thetransmission characteristics by disturbing opti-cal or, when arising, electromagnetic radiation.

A critical point is the comparability of calcula-tions and measurements of the transmissionrange. Calculating transmission ranges in thesimplest case assumes a square-law relation-ship between distance d and irradiance Ee.With a given intensity Ie, the result is

Ee = Ie/ d2

With known responsitivity of the receiverphotomodule and known intensity of thetransmitter, the transmission range can be readfrom figure 4 where the relationship is imple-mented. As a typical threshold of the receiversensitivity for safe operation, a value of0.3 mW/m2 is taken for the necessary irra-diance in figure 4. This is equivalent to thetypical specified value of the TFMS5..0 series.

The maximum sensitivity threshold is specifiedat 0.5 mW/ cm2. The typical intensity values ofselected emitters are listed in table 2.

Operating e.g. a TSIP5201 emitter at 1.5 Apulsed-forward current gives an intensity of650 mW/ sr. These data result (in combinationwith the TEMIC receiver photomodules) in atheoretical transmission range of 43.1 m (seefigure 4).

The interdependence between transmissionrange and irradiance at the location of thereceiver is shown in figure 5. The necessaryirradiance for safe reception using the receiverphotomodules of the TFMS series is alsoshown.

In practice, it is difficult to realize the quad-ratic relationship between irradiance and trans-mission distance.

In general, a smaller decrease in sensitivity isobserved due to reflection of walls and floors.This means that the example calculated here isthe worst case and in reality better transmis-sion ranges are attained.

0

10

20

30

40

50

60

0 200 400 600 800 1000 1200

Radiant intensity of the emitter [mW/sr]

Tra

nsm

issi

on

ran

ge [m

]

min.

typ.Transmission rangereceiver module TFMS5..0

Figure 4. Maximum transmission range 8 in free spacewith receiver photomodules TFMS5..0 as a function of the radiant intensity of the emitter


Distance [m]

0.01

0.1

1

10

100

1000

0 10 20 30 40 50 60

eE

[m

W/m

]

2

I = 1000 mW/sre

I = 500 mW/sre

I = 100 mW/sreeE = 0.3 mW/m 2

eE = 0.5 mW/m 2

Figure 5. Irradiance Ee as a function of the distance(parameters are the radiant intensities of the emitters)

Table 2. Emitters for remote control appliances

Emitter Technology Wavelength[nm]

RadiantFlux

I f = 100 mA

mWTyp.

RadiantIntensity

I f = 100 mA

mW/ srTyp.

RadiantIntensity

I f = 1.5 mA

mW/ srTyp.

EmissionAngle

TSIP4401 GaAlAs 950 22 25 300 ± 20°

TSIP5201 GaAlAs 950 25 50 650 ± 20°

TSIP7601 GaAlAs 950 25 20 260 ± 30°

TSUS4300 GaAs 950 13 18 160 ± 20°

TSUS4400 GaAs 950 13 15 140 ± 16°

TSUS5202 GaAs 950 15 30 280 ± 15°

TSUS5402 GaAs 950 15 30 190 ± 22°

The levels for indoor optical powers can beestimated by using other approximations. Inthis case, it is assumed that the whole innersurface of a room is irradiated with theemission of the source. To irradiate the wholesurface of a square room (e.g. area = 30 m2,height = 2.5 m) with an overall irradiance ofEe = 0.5 mW/ m2, an emitted radiant flux of

60 mW is necessary (surface = 120 m2, 100%efficiency). With 80% reflection loss, about300 mW emitted radiation will be sufficient forsafe reception in the whole room. 300 mW is avalue which can be achieved with an emitterTSIP5201 operating at a peak forward currentof 1.5 A. Under these conditions, no directpath between emitter and receiver is supposed,


but radiation after at least one reflection willreach the detector (direct reception will obeythe square law, see table 2).

Comparison of remote control systems is oftenperformed in long corridors. Such measure-ments cannot be transferred at all from onecorridor to the other because of different re-flectivity properties of walls etc. In a corridor,the function of the irradiance does not obey thesquare of the distance law. The behavior in acorridor can be described by the function:

E Ia

d

b

d

c

de e= × + +

2

The values of a, b and c must be individuallydetermined for each corridor.

The corridor, for example, where the systemmeasurements are performed at TEMIC, isdescribed in a range from 1 m to 70 m by theparameters

a = 0.93, b = 0.074, c = -0.0072.

This relationship is exactly valid for the givenemitter only. By changing the emission angleor wavelength, the reflectivity of the corridoralso changes and with it the values of the coef-ficients.


The Languages of Data Transmission Systems

In most remote control transmission systems,only small data rates are transmitted to controlthe functions of home entertainment equip-ment. A vital pre-requisite is the safety oftransmission where an incorrect interpretationof the transmitted code is not permissible. Un-intelligible signals must be ignored. Usually,commands are repeated until the remote con-trolled device reacts as desired. The operatorcan directly observe the result of pressing akey by visual feedback.

The commands can be transmitted by variationof the coding of the optical carrier. Somemethods of modulation have been established.Nowadays, only the digital transmission ofwords is used where the word length can varywhich means one word can include a differentnumber of bits.

The three commonly used representations of abit in remote control systems are described inthe following paragraphs.

The transmission of a bit using two frequencies(FSK, Frequency Shift Keying) as shown infigure 6a is accepted as a very safe method Itis, however, more expensive and consumesmore power than other methods and is there-fore rarely used.

The other two codings (see figure 6b and 6c)offer the possibility of two operating modeseither as modulated on a sub-carrier or as apulse transmission. In the applications, onlythe bi-phase modulation is found modulated ona carrier while the pulse-distance modulation isused in a carrier and a pulse-modulated mode,the so-called flash mode, respectively.

The TFM receiver photomodule series is de-veloped and optimized for the use in carrierfrequency transmission. Special types for dif-ferent operating frequencies are available inthe range from 20 kHz to 60 kHz. Standard

types are available for the frequencies 30 kHz,33 kHz, 36 kHz, 38 kHz, 40 kHz and 56 kHz.Other frequencies in this range can be realizedon request.

Flash-mode signals and the FSK cannot be re-ceived with the photomodules of the TFMseries.

The words to be transmitted consist of adefined number of bits. Word lengths andcoding method are defined in the transmissionstandards. Several transmission standards arenow accepted worldwide. Some of them aredescribed in the following paragraphs.

In European equipment, the most commonlyused standards are the RC 5 code and theRECS 80 code. Another typical transmissionlanguage is the NEC code (Far East).

The RC 5 CodeIn the RC 5 standard, a bi-phase coding isapplied (see figure 7). The carrier frequency isfixed at 36 kHz. Similar transmission standardsare used in the frequency range between30 kHz and 56 kHz.

The transmission of a word begins with twostart bits, followed by a toggle bit. The togglebit changes its value at each key operation.With this change, an interruption of the trans-mission link can be distinguished from amultiple key pressing. The five address bitsaddress the device to be controlled. Thecommand bits contain the information to betransmitted.

Each bit in a data word consists of a burst of32 pulses with a repetition rate of 36 kHz. Theequivalent times are shown on the pulse dia-grams.

To use the RC 5 code, TEMIC recommendsthe TFMx5360 series.


"1" "1" "1" "1""0" "0" "0" "0"

= f 1 = f 2

Figure 6a. Coding of a bit with two frequencies(frequency shift keying; the sequence of the transmitted frequencies determines "0" or "1")

"1" "1" "1" "1""0" "0" "0" "0"

Figure 6b. Bi-phase coding(a rising edge within a time window is equivalent to a "1", a falling edge represents a "0")

"0" "1" "1""0" "0"

Figure 6c. Pulse-distance modulation(the distances between the rising edges define the bit as "0" or "1", a short distance between two

pulses means "0", a long distance between two pulses means "1")


24,9 ms

114 ms

Data word

Data word; example:

2 start - Toggle -

5 address - 6 data - bit

One bit contains 32 pulses with a repetition rate of 36 kHz:

6.94 µs

27.8 µs

868.1 µs

Data word Data word

The data word is repeated as long as a key is pressed

Figure 7. RC 5 transmission code

The RECS 80 Code

The data word in the RECS 80 code is, with alength of 70 ms, nearly three times as long asthat in the RC 5 code. As mentioned above, theRECS 80 code operates with a digital pulsedistance modulation. As in the RC 5 code,toggle, address and command bits are used.Sometimes a flash mode is found in combina-tion with the RECS 80 code where singlepulses of infrared radiation are transmitted in-stead of bursts. A carrier frequency of 400 kHzis also used instead of the common carrier in

the range between 30kHz and 56 kHz. The IRreceiver series TFMx1..0 or TFMx1..0T areoptimized for the RECS 80 code with thesecarrier frequencies.

The TFM photomodule is not suited for receiv-ing flash mode or 400-kHz signals.

However, a combination of a TEMIC pinphoto diode (e.g. BPV23NF) with the inte-grated circuit U2506B is recommended fortransmission in the 400-kHz band.


70 ms

130 ms

Data word Data word

Figure 8a. RECS 80 pulse-distance modulation(the single bits are pulse-distance coded; see figures 6c and 8b)

2 toggle- 4 address- 6 command bits

Figure 8b. Pulse-distance modulation(example of a data word, the pulse distance for a "1" is about 7.5 ms, for a "0" about 5 ms)

140 µs

9 µs

26 µs

"Flash"

"Modulated"

Figure 8c. Pulse-distance modulation


67.5 ms

108 ms 108 ms

Data word"Leader code"

Figure 9a. NEC transmission code(the leader code followed by a single bit is transmitted as long as a key is pressed)

9 ms4.5

13.5 ms 27 ms 27 ms

Data code Data codeAddress code Address code

8 bit 8 bit 8 bit 8 bitms

Figure 9b. NEC transmission code(data word from figure 8a)

The NEC Code

The NEC code also works with bursts ofdefined carrier frequency. Therefore, receiverphotomodules of the TFMS5..0 series operateoptimally in this system.

The NEC code starts the transmission using aso-called leader code, a burst of a length of9 ms, followed by the data word after a pauseof 4.5 ms. This leader code is responsible forleveling the internal control loops in thereceiver modules of the TFM series.

As long as a key is pressed, only the leadercode is repeatedly transmitted, followed by asingle bit. A specialty of this code is the prop-erty of constant word length in connection

with a pulse-distance modulation. Both addressand command bit are transmitted twice, first asthe normal byte followed by the inverted byte.This is shown in figure 9. The burst defining abit contains 22 pulses each of a length of8.77 µs with a period of 26.3 µs. A "0" isrepresented by a pulse distance of 1.125 ms,the "1" with 2.25 ms, respectively. 8 addressbits are used to identify the device to becontrolled. A further 8 bits are used for thetransmission of the command. As mentionedabove, the words are always followed, withouta pause, by the inverted words e.g. the trans-mission of the address "00110111" and thecommand "00011010" is performed by sendingthe word: "00110111'11001000'00011010'11100101".


Description of the Detector Photomodules TFM SeriesFunctional DescriptionThe integrated circuits of the receiver photo-modules TFM are produced using TEMIC bi-polar technology.

By the design, the following features aredefined:

• High immunity against modulated and un-modulated ambient light, also against Cur-rent Wave (CW) sources

• Programmable output polarity (standard is"active low")

• Minimum of external circuitry

• Low power consumption

• Timing and output levels are microcom-puter-compatible

The function of the receiver photomodulesTFMx5..0, TFMx7..0 and TFMx1..0T can bedescribed using the block diagram in figure10a. Figure 10b explains the function of theTFMx1..0 and TFMx2..0 series. Many parts ofthe block diagrams in figures 10a and 10b aresimilar. The incident infrared radiation burstsgenerate an equivalent photo current. The DCpart is separated in the bias block and the ACpart is passed to a transimpedance amplifierfollowed by an automatic gain control ampli-fier and an integrated bandpass filter.

The final evaluation is performed by a com-parator with a Schmitt Trigger stage.

The output polarity, standard "active low", canbe changed to "active high" by an internalbond connection which can be set during pro-duction. With this feature, the designer is freeto choose the right polarity for his application.

The blocks "short burst control" and "long-time control" are responsible for the dynamiccontrol of the working points and the thresholdlevels to suppress the influences of the ambientlight and other disturbing radiation sources.The short burst control is responsible for thefast reaction and controls the reference signal

at the comparator to have the best noise sup-pression during the transmission of a dataword. The long-time control has to suppressthe disturbing influence of CW signals.

Input stage: The input stage provides the nec-essary bias voltage for the detector diode,where a 2.4 × 2.4 mm2 pin diode is used. Theblock "bias" (figures 10a and b) additionallyseparates DC- and low-frequency parts fromthe useful signal of the photo current. The lowfrequency including DC current work on alow-impedance load in the block "bias". TheAC signals are fed to the transimpedanceamplifier.

The block "bias" reacts to the photodiode as avariable frequency-dependent load resistancesimilar to on LC resonant circuit with a lowequivalent resistance for low-frequency signalsand a high resistance of some 100 kΩ at theoperating frequency. The currents at the op-erating frequency are converted by the trans-impedance amplifier (low input impedance<10 kΩ) to a voltage at the input of the AGCamplifier.

AGC Amplifier (AGC = Automatic GainControl): The AGC amplifier generates mostof the voltage gain of the whole circuitrywhereby the amplification is controlled by theoutput of the long-time control circuit. It sup-ports the interference suppression of the com-parator stage. The internal capacitive couplingresults in a high-pass behavior. The cut-offfrequency of this high pass is about 20 kHz.

Bandpass filter: The bandpass filter is tunedto the carrier frequency of the transmissionsystem during the production process. Due toits selectivity it improves the signal-to-noiseratio of the signal. Figure of merit and amplifi-cation of the filter in the TFMx5..0 series areboth approximately ten. The figure of merit inthe TFMx1..0 series is seven.

Signal evaluation: The TFMx5..0, TFMx7..0and the TFMx1..0T series have a single com-


parator level which is controlled by the Auto-matic Threshold Control (ATC) or the short-burst control and the long-time control(figure 9a). The level VT sets the sensitivitylevel of the evaluation. The TFMx1..0 andTFMx2..0 series use two comparators(figure 10b). One has a constant threshold atthe lowest level VT and the other is controlledby the ATC. At low signals, the comparatorwith the constant threshold level is used forevaluation. With large signals, the threshold ofthe second comparator is evaluated. Its level isshifted by the ATC to the half value of theactual signal level. This technique prevents thepunch-through of small interference voltagesto the output (e.g., disturbing bursts during adata telegram).

The integrator (INT) is triggered depending onthe above mentioned comparison. It controlsthe output via the Schmitt Trigger (ST). Theintegrator additionally prevents the feed-through of short disturbances to the output.

The internal pull-up resistor of R = 100 kΩ onthe output transistor can be used as a singleload and can, according to the application,replace the external load resistor. An externalresistor can operate in parallel. The outputcurrent is internally limited to about 10 mA.

Short-time control: The comparator stage isas sensitive as possible in the quiescent mode.The short-time control reduces the sensitivityat the comparator stage shortly after the firstsignal arrives to that level, where the signalrecognition can be expected with safety. Withthis method, disturbances can be efficientlyprevented from being detected as a falselytransmitted signal during the transmission ofan information block. This reduction of sensi-tivity is performed by increasing the potentialat the inverting input of the signal comparator.The RC combination represents the time con-stant (t < 15 ms) of the short-time controlwhich is fitted well to the common transmis-sion codes.

Trans-impedanceamplifier AGC

BPF

Long-timecontrolciruit

INT ST

GND

Output

C1

R2

R1

+ 5 V

COMP

Short-burstcontrol

VTBias 100 k

Figure 10a. Block diagram of the receiver photomodules TFMx5..0, TFMx1..0T and TFMx7..0


+-

&Vth

Comp 1

Comp 2 ATC DEM

+-

BPF

AGC

BIAS

GND

TIA CGA INT ST

OUT

VS

94 9286

100kΩ

Figure 10b. Block diagram of the receiver photomodules TFMx1..0 and TFMx2..0

Long-time control: This circuit ensures thatthe receiver photomodule is immune to distur-bances. It adapts to the existing noise or distur-bance level by changing the sensitivity at thecomparator input and the gain of the AGCamplifier. The reduction of the sensitivity isalso effected, as with the short-time control, byincreasing the potential at the inverting com-parator input. The time constant of the long-time control is chosen to be suitably large toavoid a considerable sensitivity decreaseduring the transmission.

All continuous disturbing signals (CWsources) are extremely well suppressed by thelong time control and the AGC stage. Apartfrom the ATC which is described above,special techniques can be implemented in orderto suppress shorter disturbances. In theTFMx1..0T, TFMx2..0 and TFMx5..0 series,an integrated mono-flop function inside thelong time control block ensures that short dis-turbances are weighted stronger for shifting theAGC level. In the TFMx1..0 series, also shortdisturbance signals are weighted stronger thanthe (useful) longer bursts because the AGC isaffected mainly during the load time of theintegrator in this circuit.

As the duty cycle of the data transmission isvery low, the long-time control does notreduce the sensitivity while it is receiving adata telegram. The exact duty cycle limitationsfor each TFM series are given in the followingchapter.

Behavior Under Operational Condi-tionsTo assure optimal operation of the receiverphotomodule TFMS5..0 under all thinkableapplication conditions, it is necessary toevaluate the behavior of this device at differentboundary conditions. In the next chapter, theinfluence of different parameters in the appli-cation is evaluated. Emphasis is placed on thedifferences of the TFMx families. These datawill help to optimize the appliance of thereceiver photomodules.

Properties and ApplicationsDifferent Telegram Conditions

Influence of the short-time control: Theshort-time control raises the threshold for thesignal evaluation to an optimized workingpoint to assure the best signal-to-noise ratio for


the received signal. Between the single burstsof the transmission telegram, the thresholdslides back towards the initial value with atime constant of t = 15 ms until the next burstagain adjusts the threshold level.

In the quiescent mode, i.e. no signal on thereceiver photomodule, the circuit is controlledto its most sensitive working point. Thisworking point is determined by the magnitudeof the input noise which should not cause anysignal at the output. However, due to the statis-tical distribution of the input noise, singlepulses occasionally occurring at the outputcannot be avoided. This should not present anyproblem for the signal processor following thephotomodule as long as the likelihood ofnoise-generated pulses is small.

As mentioned before, in the quiescent modethe threshold is very low. Starting with the firstburst of a transmission telegram, the short-timecontrol is activated. Therefore, the switching-on time for the output signal generated by thefirst burst is about 2/frfg (frfg = rated frequen-cy) shorter than the following bursts. Thisbehavior should be considered in theevaluation software of the processor or shouldbe eliminated by a leader code as in the NECtransmission code.

During the transmission, the control loops areset to those working points which guaranteethe best signal-to-noise ratio. When usingtransmission codes with burst intervals oftrep > 15 ms within the telegram, the thresholdruns down during the pauses to the noise-controlled level. This mode of operationshould be avoided because it is impossible toadjust the noise-optimized working point. Thelikelihood of noise or background radiation-generated output signals will increase. If thiscannot be avoided, the signal processor soft-

ware must tolerate or compensate such errorsto prevent extended reaction times and adul-terated transmissions.

Influence of the long-time control: The long-time control adapts the threshold level to theexternal disturbance sources e.g. RF- and opti-cal CW signals. The long-time control circuitcan distinguish between useful signals anddisturbances as long as the transmission main-tains the duty cycle condition of each type (seenext chapter).

The conditions must be observed also whentransmitting larger amounts of data as inspecial TV applications where long transmis-sion blocks are used for service adjustments ofthe equipment. In this so-called factory mode,the duty cycle is increased to a maximum tol-erable value and a sensitivity loss is accept-able.

When this limit is exceeded, the sensitivity ofthe receiver photomodule decreases continu-ously. For CW signals, the module is thentotally insensitive because by design, CW sig-nals are per definition disturbances. The de-pendence of resulting sensitivity on the appliedduty cycle is shown in the data sheet.

Influence of the IntegratorThe integrator stage needs a minimum burstlength until the output is switched. Therefore,the integrator can suppress disturbances suchas short bursts or spikes. An optimum functionin the application of the receiver photomodulesis achieved by using burst lengths representingone bit not shorter than the special integrationtime of the series. The gap between two burstsmust also exceed a minimum time period(recovery time of the integrator). The varioustiming requirements for the TFM series aregiven in the next chapter.


Features and Restrictions of the Various Components in theTFM SeriesTo enable the remote control system to func-tion correctly, the most suitable type of theTFM series has to be chosen regarding thecriteria of the transmission code (duty cycle,

burst length, gap length) and its decodingmethod. The duty cycle is defined in theexample given in figure 11 and is as given atthe bottom of this page.

Table 3. Timing requirements for the various TFM seriesMaximum Duty Cycle Minimum Burst

LengthMinimum Gap

LengthTiming Toleranceof Output Pulses

TFMx1..0 N/ (14.2 + 1.1 × N) 6/ fo 10/ fo −3/ fo + 6/ foTFMx1..0T 1/ [6 × (1 + 0.25 ms/ N/ fo)] 150 µs 250 µs −100 µs + 160 µs

TFMx2..0 1/ [4 × (1 + 0.67 ms/ N/ fo)] 17 fo 17 fo −5/ fo + 8/ foTFMx5..0 1/ [6 × (1 + 0.25 ms/ N/ fo)] 400 µs 400 µs +/ − 160 µs

TFMx7..0 1/ [6 × (1 + 0.25 ms/ N/ fo)] 400 µs 400 µs +/ − 160 µs

fo = Carrier frequency of transmission, N = Number of periods in a burst

Table 4. Time requirements example(typical transmission code with 22 periods in a burst at 38 kHz)

Maximum Duty Cycle Minimum BurstLength

Minimum GapLength

TimingTolerance of

Output PulsesTFMx1380 0.57 160 µs 260 µs −80 µs + 160 µs

TFMx1380T 0.12 160 µs 250 µs −100 µs + 160 µs

TFMx2380 0.12 450 µs 450 µs −130 µs + 210 µs

TFMx5380 0.35 400 µs 400 µs +/ − 160 µs

TFMx7380 0.35 400 µs 400 µs +/ − 160 µs

Duty cycle =( ) ( ) ( ) ( )T T T T T T T T

trep

2 1 4 3 6 5 8 7− + − + − + −

If a data transmission language uses differentburst lengths (N), the calculation can be donewith an average burst length. As the long timecontrol reacts very slowly, examinations of the

duty cycle should be carried during a longinterval time (about 150 ms). The duty cyclemay be higher than the limit which ismentioned here for a short amount of timewithout loss of sensitivity (< 100 ms). How-ever, if the application is carried out for longerthan the duty-cycle boundary value, the sensi-tivity decreases slightly.

T1 T2 T3 T4 T5 T6 T7 T8 T1'

t rep = 20 ms

Figure 11. Duty cycle of a common transmission telegram


Working ConditionsMeasurement Procedure and TestCircuitIn the block diagram (figure 10a), two resistors(R1, R2) and one capacitor are given as addi-tional external components in the applicationcircuit. These external components are op-tional and depend on the quality of the powersupply conditions and the demands of the cir-cuit that follows. R2 is the optional load resis-tor which can operate if necessary in parallel tothe internal 100 kΩ load. The minimum resis-tance of R2 is 10 kΩ. In the specification, thefilter combination R1/ C1 with C1 = 4.7 µFand R1 = 330 Ω is recommended to suppressdisturbances on the power line. The parts canbe omitted when no disturbances are expected.

The influence of the power line disturbanceson the function of the device can be taken fromthe presentation of the threshold sensitivity vs.the amplitude of the disturbance (at center op-erating frequency) on the power line (see theenclosed data sheet). In the application, the R1/C1 combination should be optimized, alsoregarding the commercial point of view and, ifpossible, omitted. In test circuits, this combi-nation always should be implemented to obtaintrue measurements.

The definition of the sensitivity of a digitallyswitching receiver front end is a problem.When increasing the irradiance from zero onthe receiver photomodule at a certain level, theoutput starts to react statistically to the inputsignal. The pulse lengths at the output are not amirror of the envelope of the input signal. Withincreased signal strength, the likelihood of cor-rect recognition is increased and the pulselengths are a reproduction of the input enve-lope.

To obtain defined conditions for the measure-ment, an error tolerance is fixed for the delayand pulse length deviations of the output sig-nal.

Table 5. Time windows for signal evaluation

Delay of LeadingEdge

TimingTolerance withOutput Pulse

WidthTFMx1380 4/ fo < td < 10/ fo −3/ fo + 6/ foTFMx1380T 100 µs < td

< 300 µs-100 µs + 160 µs

TFMx2380 11/ fo < td < 19/ fo -5/ fo + 8/ foTFMx5380 100 µs < td

< 400 µs+/ − 160 µs

TFMx7380 100 µs < td< 400 µs

+/ − 160 µs

Definition: The threshold sensitivity is thatirradiance, at which the measured values ofdelay and output pulse length all are inside thetolerated band.

Sensitivity in Dark AmbientA remark is necessary before the definition andthe measurement of this parameter are de-scribed: When comparing different transmis-sion systems, the measured sensitivity in adark ambient is the parameter mostly measuredfirst although this condition is hardly present inthe real application. The typical application ofentertainment electronics is in a light ambient,e.g., a television receiver is rarely operated intotal darkness because the light from the screenwill illuminate the ambient. Therefore, theTFM series is optimized for operation in adisturbed and light ambient.

The sensitivity threshold in dark ambient ismeasured using the definition in the chapter“Measurement Procedure and Test Circuit“.The sensitivity is discussed from an opticalpoint of view in the chapter "Sensitivity“.

The output pulse length in response to an inputburst is drawn the data sheet. The phenomenondescribed in the chapter "Measurement Proce-dure and Test Circuit", the dependence of theoutput pulse length on the input signal, can bedemonstrated here. At an irradiance at about


0.1 mW/ m2, short pulses arrive at the output.With the irradiation increased to 0.3 mW/ m2,the output signal length typically reaches thelength of the input burst length. This length hasnot changed more than that inside the smalltolerance field defined already up to an irra-diation of 100 W/ m2. This means, an over-driving or dynamic of nearly six orders ofmagnitude is allowed. A TV remote controlwith a built-in TFM works typically in a dis-tance range from half an inch (direct contact,distance given by front plate) to more than120 feet.

Disturbing Optical RadiationThe built-in control circuits and loops adjustthe sensitivity threshold to the most sensitiveworking point at the existing background il-lumination and other radiation from optical andelectrical sources. These sources can be incan-descent lamps, standard fluorescent lamps, andin particular energy-saving electronic fluores-cent lamps. The photo current generated in theinternal detector diode induces a current noisewhich limits the sensitivity with backgroundunmodulated light. The light of incandescentlamps is almost unmodulated or exhibits only asmall modulation depth. Gas discharge lampsare strongly modulated with the operatingcurrent and are therefore more critical sourcesin respect to disturbances.

Fluorescent lamps occupy a special position inthe field of optical disturbers. These lampsemit infrared disturbances such as a shortburst, synchronous to the double-line frequen-cy (2 × 50 Hz or 2 × 60 Hz equivalent to aperiod of 10 ms or 8.33 ms, respectively) andvery similar to transmission codes. Such dis-turbers can cause an increase in the likelihoodof line frequency synchronous output signalsof the module.

This must be taken into consideration in appli-cations with very high illuminances from fluo-rescent lamps to avoid transmission codes withrepetition rates similar to that of the line fre-quency (and its harmonics). Furthermore, the

software evaluation of the code should sup-press these kinds of disturbances.

The threshold irradiance (in other words thesensitivity) as a function of the irradiance isshown in the data sheet. In order not to gener-ate false output pulses by the noise of the inputsignal, the internal threshold must be decreasedresulting in decreased sensitivity. As an ex-ample, an irradiance by dc ambient light of18 W/ m2 enables the module to still operatewith a threshold sensitivity of 2 mW/ m2. Thedc ambient light in this case causes a photocurrent 1000 times larger than the signal to bedetected. From table 1, it can be seen that thisambient irradiance is equivalent to an illumi-nance with sunlight of 14700 Lux. Typicalworking place illumination uses illuminancesof 500 - 1500 Lux.

Behavior in Electromagnetic FieldsA most unpleasant ambient with regard toelectromagnetic sources is the inside of tele-vision receivers. The horizontal deflectionoperates at a frequency of 15625 Hz (625 × 25)or 15750 Hz (525 × 30). The harmonics with31250 Hz or 31500 Hz are directly on or in theneighborhood of the remote control carrier fre-quencies. With a standard selectivity, the inter-ference cannot be suppressed electrically at areasonable cost. An excellent suppression ofdisturbances is achieved by constructivemeasures in the design such as e.g. the rightposition of the detector chip inside the pack-age, very short wire connections, shielding ofthe chip and an internal shield in the package.Here, the advantages of the compact packagecompared to printed circuit boards could bedemonstrated. At applied field strengths of700 V/ m at the rated carrier frequency, thesensitivity is only reduced by a factor of two,equivalent to a loss of transmission range ofabout 30%.

The receiver photomodule exposed to opticaland electrical disturbances from its ambientwill show reduced sensitivity, but because ofits design it will not show a malfunction. The


measures taken to suppress interferences arepart of a patent pending from TEMIC.

The dependence of the sensitivity as a functionof applied field strength is shown in the datasheet.

Influence of Disturbed VS

The receiver photomodule should operate witha stable supply voltage to prevent a sensitivitydecrease. This decrease depends on the ampli-tude and the frequency of the disturbance. Asmentioned above, disturbances from the har-monics of deflection currents in TV sets are inthe remote control band. Because the deflec-tion currents are high, an interaction with thepower supply voltage is possible. There is alsoa possibility of interference with emitted RFsignals, in particular with subharmonics of theoperating frequency when using switchmodepower supplies. In the data sheet, the relationbetween sensitivity and power supply distur-bances is shown for 100 Hz, 10 kHz and forthe rated center.

SensitivityAs already described in the subchapter„Measurement Procedure and Test Circuit“,the sensitivity of a digital device must be de-scribed with a threshold. The criteria of thisthreshold is the true to form transmission of theirradiant signal. Spectral sensitivity and angu-lar dependence are measured under the sameconditions as those mentioned above and aregiven in the data sheet as values relative to thereference point.

Spectral sensitivity: The maximum relativespectral sensitivity of the TFMS5..0 series is at950 nm. The decline on the long-wave lengthside is predetermined by the absorption prop-erties of silicon, whereby the thickness of theabsorbing layer and some other parameters in-fluence the gradient of the decline. The shortwavelength flank is determined by the filterpigmentation of the plastic package.

The receiver characteristic is made narrowbandon purpose to prevent as much radiation aspossible from wideband disturbances reachingthe detector.

This characteristic has been optimized for the950 nm emitter radiation (see table 2).

System losses result when emitters of 870 nmor less are incorporated. Principally, a dis-placement of the short wavelength flank toshorter wavelengths is possible without prob-lem if an applier wants to work with emittersof 840 nm, 870 nm or even 660 nm. However,in these cases the ambient light compatibilitysuffers.

Angular dependence: A large angular open-ing of the detector is desired for remote controlapplications to enable detection of scatteredradiation. The lens arrangement, referring tothe same chip area gives a gain of 2, whereasthe angle characteristic approximates to thecos2 law. Larger central sensitivity can be real-ized at a reduced angular opening, but largerangular openings lead to reductions in thestability with regard to electrical disturbances.

Typical CircuitryUp to now, the internal circuitry, the functionand the usual operation of the photomodule hasbeen described. It is therefore advisable to givehere a few tips on the standard circuits andevaluation processes.

At present, two ways for the evaluation arepursued: Either special circuits are used toevaluate the remote control recordings (see“Typical Application Circuit“) or the evalua-tion is left for execution by the equipment (see“Recommendations for Evaluation“).

Typical Application CircuitVarious manufactures offer circuits for decod-ing remote control signal. The circuitry infigure 12 incorporates the SAA3049 circuitdevice.


+ 5 V Vcc

SAA3049

Vbatt

Remote

TFMS5..0TSUS ....

TSIP ....

Data

Toggle

Address

4 MHz

controltransmitter

SAA3010

Figure 12. Typical circuit for decodingremote control signals

Recommendations for EvaluationA transmitted telegram consists of pulseswhich reach the photomodule as optical sig-nals. The output signal of the TFM presents analmost exact reproduction of the envelope ofthis signal. If the input signal is large enoughthe delay times for the rise- and decay flankswill be the same. The amplification control hasreduced the sensitivity of the photomodule to alevel where disturbances are not registered. Insuch a case, the first incoming flank causes an

interrupt and the time to the following flanks ismeasured. This method, however, runs thedanger that disturbances are accepted as sig-nals and consequently wrong interpretationsare the results. Disturbances are most likelywhen dealing with weak signals and should besuppressed by the software accordingly.

For example, one method used is to examinethe record after an interrupt has occurred in apredetermined time window to see which typeof flank of the logic signal was present(increasing or decreasing). In addition, it ispossible to evaluate the pulse length with thecorresponding second flank of a pulse toqualify and re-iterate the information obtainedfirst. A filter for the input signal is effected inthis manner resulting in ensured transmissionover long distances.

To ease the burden on the processor during theserial acceptance of the data, a plausibility testshould be performed on the signals alreadyentered. If the test shows that the pulse se-quence is non-sensical then the data word thathas been entered must be rejected.

Table 6. Comparison of various manufacturers photomodules under differing ambient conditions

TypeandOrigin

Sensitivity inDark Ambient/

ThresholdIrradiance

Threshold Irrad.at 15 W/m2 DC

DisturbanceLight

ThresholdIrrad. at AC

Disturbance Light(4 m W/ m2, f = fo)

SensitivityAgainst

Electrical FieldDisturbance

Unexp. OutputPulses under

15 W/ m2 AmbientDC Light

mW/ m2 mW/ m2 mW/ m2 V/ m min.

TEMICTFMS5360

0.33 1.6 15 1000 5

TEMICTFMS1380

0.32 1.4 16 1000 7

A Japan 0.35 8.2 50 600 10 000

B Japan 0.3 7.4 9 260 4000

C Japan 0.36 2.5 9 320 1000

D Japan 0.64 5.5 > 999 2500 2

E Japan 0.51 5.1 > 999 5000 5

F Japan 0.62 13 > 999 380 0

G Korea 0.67 5.2 10 600 10

H Taiwan 0.4 5.2 13 120 5


AppendixComparison TestTable 6 shows the results of tests carried out inTEMIC laboratories on the TFM photomoduleand other manufacturers’ versions. The sensi-tivity threshold was determined with 600bursts, burst interval 10 ms, burst length 30pulses with a duty cycle 1:1 at the nominal fre-quency. The criteria for reaching the sensitivitythreshold is that 598 from 600 pulses with atime tolerance of ±160 µs must be recognized.The threshold was determined at various envi-ronmental conditions that may occur in theremote control ambient.

The ambient light suppression was tested at anirradiance of 15 W/m2. The resulting effect issimilar to that of a 1.5-kLux incandescentlamp. The source was an emitter with a wave-length of 950 nm. The compatibility withregard to electromagnetic disturbances wasmeasured at a field strength of 100 V/m. Fre-quency of the disturbance was also the nominalfrequency of the photomodule.

Please note: The TFM series is specified forambient temperatures of 85°C, whereas othermanufacturers only guarantee this function upto 65°C.

SummaryThe TFM series for remote control systemsrepresent a new generation of highly sensitiveintegrated detectors. These devices are optimalfor the most widely used transmission methodwith either phase- or pulse-length modulation.

The most prominent property of the photo-module is the optimal transmission safety at ahigh sensitivity under disturbed ambient con-ditions. This safety and the long range guaran-tee the employer a secure function of his trans-

mission system also under difficult ambientconditions. A further advantage is the compactform.

The ISO9001-controlled automatic large-volume production lines guarantee a continu-ously high reliability of the devices. TEMICoffers the manufacturers of modules the safetyof a mature product. The devices contain themany years of experience of Europe's leader ininfrared receivers.

Plastic Suppliers

U.S.

Bayer CorporationPlastic DepartmentPittsburg/PA 15205-9741Fax: +1 412 7777 621

GE PlasticONE Plastic AvenuePittsfield/MA 01201Fax: +1 4134 487 493

Taiwan

Bayer Taiwan Co. Ltd.P.O.Box 5535Taipei - 10-477Fax: +88 6250 780 43

Hong Kong

Bayer Far East Service Co. Ltd.Fax: +852 28955888

Singapore

Bayer (Singapore) Pte. LtdFax: +65 2664866


Package Dimensions

TFMC

TFMK


TFMM

TFMS (A, D, G, K)


TFMS (B, F, U)

TFMS (C)


TFMS (E)

TFMS (I)


TFMT

TFMU


TFMW

TFMX


TFMY


TFMS 1..0

TELEFUNKEN SemiconductorsRev. A4, 29-Aug-96

1 (6)

Photo Modules for PCM Remote Control Systems

Special series with short integration time for short burst codes or enhanceddata rates

Available types for different carrier frequencies Type f0 Type f0

TFMS 1300 30 kHz TFMS 1330 33 kHz

TFMS 1360 36 kHz TFMS 1370 36.7 kHz



DescriptionThe TFMS 1..0 – series are miniaturized receivers for in-frared remote control systems. PIN diode andpreamplifier are assembled on lead frame, the epoxypackage is designed as IR filter. The demodulated output signal can directly be decodedby a microprocessor. The main benefit is the reliablefunction even in disturbed ambient and the protectionagainst uncontrolled output pulses.

94 8691

GNDVS OUT

Features Receiver module for transmission codes with

short bursts (N6 pulses per bit) Photo detector and preamplifier in one package Output active low

(active high modules: TFMS 1..9) Internal filter for PCM frequency High immunity against ambient light, optimized

against burst noise

Improved shielding against electric field disturbance

5 Volt supply voltage TTL and CMOS compatibility

Low power consumption (typical 2.5 mW) 2.4 kbit/s data transmission rate possible

(N=6, fo=56 kHz)

Block Diagram

94 9148

PIN

Input

AGC

ControlCircuit

BandPass

Demodu-lator

100 k

1

2

3

VS

OUT

GND

TFMS 1..0


2 (6)

Absolute Maximum RatingsTamb = 25C

Parameter Test Conditions Symbol Value Unit

Supply Voltage (Pin 2) VS –0.3...6.0 V

Supply Current (Pin 2) IS 5 mA

Output Voltage (Pin 3) VO –0.3...6.0 V

Output Current (Pin 3) IO 5 mA

Junction Temperature Tj 100 C

Storage Temperature Range Tstg –25...+85 C

Operating Temperature Range Tamb –25...+85 C

Power Consumption (Tamb 85 C) Ptot 50 mW

Soldering Temperature t 10 s, 1 mm from case Tsd 260 C

Basic CharacteristicsTamb = 25C

Parameter Test Conditions Symbol Min Typ Max Unit

Supply Current (Pin 2) VS = 5 V, Ev = 0 ISD 0.4 0.5 0.8 mApp y ( )

VS = 5 V, Ev = 40 klx, sunlight ISH 1.0 mA

Transmission Distance Ev = 0, test signal see fig.7, IR diode TSIP5201, IF = 0.5 A

d 32 m

Output Voltage Low (Pin 3) IOSL = 0.5 mA,Ee = 0.7 mW/m2, f = fo, test signal see fig.7

VOSL 250 mV

Irradiance (30 – 40 kHz) Test signal see fig.7 Ee min 0.4 0.6 mW/m2

Irradiance (56 kHz) Test signal see fig.7 Ee min 0.45 0.7 mW/m2

Irradiance Test signal see fig.7 Ee max 20 W/m2

Directivity Angle of half transmission distance ϕ1/2 ±55 deg

Application Circuit

94 9220

TSUS 5...TSIP 5...

TFM. 1..02

3

1

4.7 F *)

C

>10 koptional

330 *) +5V **)

*) only necessary to suppress power supply disturbances**) tolerated supply voltage range : 4.5V<VS<5.5V

GND

TFMS 1..0


3 (6)

Typical Characteristics (Tamb = 25C unless otherwise specified)

0.7 0.8 0.9 1.0 1.1

E

/

E

– R

el. R

espo

nsiti

vity

( %

)e

min

f / f 0 – Relative Frequency

1.3

94 9102

0.0

0.2

0.4

0.6

0.8

1.0

e

1.2

f = f05%f ( 3dB ) = f0/7

Figure 1. Frequency Dependence of Responsivity

0.1 1 10 100 10000

50

100

150

200

300

10000

94 9185

250

t –

Out

put P

ulse

Len

gth

( s

)po

Ee – Irradiance ( mW/m2 )

= 950 nm, Optical Test Signal, Fig.7

Input Burst Duration

Figure 2. Sensitivity in Dark Ambient

0.01 0.1 1 100.1

1

10

100

E

–

Thr

esho

ld Ir

radi

ance

( m

W/m

)

e m

in

E – Irradiance ( W/m2 )

100

94 9104

2

Ambient, = 950 nm

Correlation with Ambient Light Sources(Disturbance Effect ) :10W/m21.4klx

(Stand.Illum.A,T=2855 K)8.2klx(Daylight,T=5900 K)

Figure 3. Sensitivity in Bright Ambient

0 0.4 0.8 1.2 1.60

0.2

0.4

0.6

0.8

1.0

2.0

94 9105 E – Field Strength of Disturbance ( kV /m )

E

–

Thr

esho

ld Ir

radi

ance

( m

W/m

)

e m

in2

f (E )= f0

f (E )=10kHz

Figure 4. Sensitivity vs. Electric Field Disturbances

0.01 0.1 1 10 1000.1

1

10

1000

94 9106 Vs RMS – AC Voltage on DC Supply Voltage (mV)

E

–

Thr

esho

ld Ir

radi

ance

( m

W/m

)

e m

in2

f = f0

10 kHz

100 Hz

1 kHz

Figure 5. Sensitivity vs. Supply Voltage Disturbances

E

–

Thr

esho

ld Ir

radi

ance

( m

W/m

)

e m

in2

–30 0 30 600.0

0.2

0.4

0.6

0.8

1.0

Tamb – Ambient Temperature ( °C )

90

94 9107

Sensitivity in dark ambient

Figure 6. Sensitivity vs. Ambient Temperature

TFMS 1..0


4 (6)

Ee

T

tpi *t

N6 Pulses is recommended for optimal function

VO

VOH

VOL

tpo2 )

t

94 9181

Optical Test Signal( IR diode TSIP 5201, IF=1.5 A, N=6 pulses, f=f0, T=10 ms )

Output Signal

td1 )

1 ) 4/f0 < td < 10/f02 ) tpi – 3/f0 < tpo < tpi + 6/f0

Figure 7. Output Function

Ee

t

VO

VOH

VOLt

600 s 600 s

T = 60 ms

Ton Toff

94 8134

Optical Test Signal

Output Signal, ( see Fig.10 )


0 0.2 0.4 0.60

0.5

1

1.5

2

3

0.8

94 9186 tp/T – Duty Cycle

E

–

Thr

esho

ld Ir

radi

ance

( m

W/m

)

e m

in2

N=6 N=32N=16

2.5

Figure 9. Sensitivity vs. Duty Cycle

0.1 1 10 100 1000

T

,T

-

Out

put P

ulse

Len

gth

( m

s )

on


10000

94 9187

0.0

0.2

0.4

0.6

0.8

1.0

Ton

Toff


off

Figure 10. Output Pulse Diagram

I –

Sup

ply

Cur

rent

( m

A )

s

Tamb – Ambient Temperature ( °C )94 9110

–30 0 30 600.0

0.2

0.4

0.6

0.8

1.0

90

Vs = 5 V

Figure 11. Supply Current vs. Ambient Temperature

750 850 950 10500

0.2

0.4

0.6

0.8

1.2

S (

)

– R

elat

ive

Spe

ctra

l Sen

sitiv

ityre

l

– Wavelength ( nm )

1150

94 8408

1.0

Figure 12. Spectral Response

TFMS 1..0


5 (6)

x

y

00.4 0.2 0.2 0.4

–30

drel – Relative Transmission Distance

0.6

94 8152

0.6

0 10–10–20 20

–40

Figure 13. Vertical Directivity ϕy

94 8153

00.4 0.2 0.2 0.4

–30


0.60.6

0 10–10–20 20

–40

Figure 14. Horizontal Directivity ϕx

Dimensions in mm

96 12116

TFMS 1..0


6 (6)

Ozone Depleting Substances Policy Statement

It is the policy of TEMIC TELEFUNKEN microelectronic GmbH to

1. Meet all present and future national and international statutory requirements.

2. Regularly and continuously improve the performance of our products, processes, distribution and operating systemswith respect to their impact on the health and safety of our employees and the public, as well as their impact onthe environment.

It is particular concern to control or eliminate releases of those substances into the atmosphere which are known asozone depleting substances (ODSs).

The Montreal Protocol (1987) and its London Amendments (1990) intend to severely restrict the use of ODSs andforbid their use within the next ten years. Various national and international initiatives are pressing for an earlier banon these substances.

TEMIC TELEFUNKEN microelectronic GmbH semiconductor division has been able to use its policy ofcontinuous improvements to eliminate the use of ODSs listed in the following documents.

1. Annex A, B and list of transitional substances of the Montreal Protocol and the London Amendments respectively

2. Class I and II ozone depleting substances in the Clean Air Act Amendments of 1990 by the EnvironmentalProtection Agency (EPA) in the USA

3. Council Decision 88/540/EEC and 91/690/EEC Annex A, B and C ( transitional substances) respectively.

TEMIC can certify that our semiconductors are not manufactured with ozone depleting substances and do not containsuch substances.

We reserve the right to make changes to improve technical design and may do so without further notice.Parameters can vary in different applications. All operating parameters must be validated for each customer

application by the customer. Should the buyer use TEMIC products for any unintended or unauthorizedapplication, the buyer shall indemnify TEMIC against all claims, costs, damages, and expenses, arising out of,

directly or indirectly, any claim of personal damage, injury or death associated with such unintended orunauthorized use.

TEMIC TELEFUNKEN microelectronic GmbH, P.O.B. 3535, D-74025 Heilbronn, GermanyTelephone: 49 (0)7131 67 2831, Fax number: 49 (0)7131 67 2423

TFMS 5..0

TELEFUNKEN SemiconductorsRev. A4, 15-Jul-96

1 (6)

Photo Modules for PCM Remote Control Systems

Available types for different carrier frequencies

Type f0 Type f0TFMS 5300 30 kHz TFMS 5330 33 kHz

TFMS 5360 36 kHz TFMS 5370 36.7 kHz


TFMS 5560 56 kHz

DescriptionThe TFMS 5..0 – series are miniaturized receivers for in-frared remote control systems. PIN diode andpreamplifier are assembled on lead frame, the epoxypackage is designed as IR filter. The demodulated output signal can directly be decodedby a microprocessor. The main benefit is the reliablefunction even in disturbed ambient and the protectionagainst uncontrolled output pulses.

94 8691

GNDVS OUT

Features Photo detector and preamplifier in one package

Output active low (active high modules: TFMS 5..9)

Internal filter for PCM frequency

High immunity against ambient light

Improved shielding against electric field disturbance

5 Volt supply voltage, low power consumption

TTL and CMOS compatibility

Continuous transmission possible (tpi/T0.4)

Block Diagram

94 8136

PIN

Input

AGC

ControlCircuit

BandPass

Demodu-lator

100 k

1

2

3

VS

OUT

GND

TFMS 5..0


2 (6)

Absolute Maximum RatingsTamb = 25C

Parameter Test Conditions Symbol Value Unit

Supply Voltage (Pin 2) VS –0.3...6.0 V

Supply Current (Pin 2) IS 5 mA

Output Voltage (Pin 3) VO –0.3...6.0 V

Output Current (Pin 3) IO 5 mA

Junction Temperature Tj 100 C

Storage Temperature Range Tstg –25...+85 C

Operating Temperature Range Tamb –25...+85 C

Power Consumption (Tamb 85 C) Ptot 50 mW

Soldering Temperature t 10 s, 1 mm from case Tsd 260 C

Basic CharacteristicsTamb = 25C

Parameter Test Conditions Symbol Min Typ Max Unit

Supply Current (Pin 2) VS = 5 V, Ev = 0 ISD 0.4 0.5 0.8 mApp y ( )

VS = 5 V, Ev = 40 klx, sunlight ISH 1.0 mA

Transmission Distance Ev = 0, test signal see fig.7, IR diode TSIP5201, IF = 1.5 A

d 35 m

Output Voltage Low (Pin 3) IOSL = 0.5 mA,Ee = 0.7 mW/m2, f = fo, tp/T = 0.4

VOSL 250 mV

Irradiance (30 – 40 kHz) Pulse width tolerance:tpo=tpi±160s, test signal (see fig.7)

Ee min 0.3 0.5 mW/m2

Irradiance (56 kHz) Pulse width tolerance:tpo=tpi±160s, test signal (see fig.7)

Ee min 0.4 0.7 mW/m2

Irradiance Ee max 20 W/m2

Directivity Angle of half transmission distance ϕ1/2 ±55 deg

Application Circuit

94 8137

TSUS 5...TSIP 5...

TFM. 5..02

3

1

4.7 F *)

C

>10 koptional

330 *) +5V **)

*) only necessary to suppress power supply disturbances**) tolerated supply voltage range : 4.5V<VS<5.5V

GND

TFMS 5..0


3 (6)

Typical Characteristics (Tamb = 25C unless otherwise specified)

0.7 0.8 0.9 1.0 1.1

E

/

E

– R

el. R

espo

nsiti

vity

( %

)e

min

f / f 0 – Relative Frequency

1.3

94 8143

0.0

0.2

0.4

0.6

0.8

1.0

e

1.2

f = f05%f ( 3dB ) = f0/10

Figure 1. Frequency Dependence of Responsivity

0.1 1.0 10.00

200

400

600

1000

1200

t –

Out

put P

ulse

Len

gth

( s

)po


100.0

94 8145

800


Input Burst Duration

Figure 2. Sensitivity in Dark Ambient

0.01 0.1 1.0 10.00.1

1.0

10.0

100.0

E

–

Thr

esho

ld Ir

radi

ance

( m

W/m

)

e m

in

E – Irradiance ( W/m2 )

100.0

94 8146

2

Ambient, = 950 nm

Correlation with Ambient Light Sources(Disturbance Efect ) :10W/m21.4klx(Stand.Illum.A,T=2855 K)8.2klx

(Daylight,T=5900 K)

Figure 3. Sensitivity in Bright Ambient

0.0 0.4 0.8 1.2 1.60.0

0.4

0.8

1.2

2.0

E – Field Strength of Disturbance ( kV /m )

2.0

94 8147

1.6

E

–

Thr

esho

ld Ir

radi

ance

( m

W/m

)

e m

in2

f (E )= f0

Figure 4. Sensitivity vs. Electric Field Disturbances

0.1 1 10 1000.1

1

10

100

Vs RMS – AC Voltage on DC Supply Voltage (mV)

1000

94 8148

E

–

Thr

esho

ld Ir

radi

ance

( m

W/m

)

e m

in2

f = f0

10 kHz

100 Hz

Figure 5. Sensitivity vs. Supply Voltage Disturbances

E

–

Thr

esho

ld Ir

radi

ance

( m

W/m

)

e m

in2

–30 0 30 600.0

0.2

0.4

0.6

0.8

1.0

Tamb – Ambient Temperature ( °C )

90

94 8149

Sensitivity in dark Ambient

Figure 6. Sensitivity vs. Ambient Temperature

TFMS 5..0


4 (6)

Ee

T

tpi *

t

* tpi 400 s is recommended for optimal function

VO

VOH

VOL

tpo

tpo = tpi 160 s

t

94 8133

Optical Test Signal( IR diode TSIP 5201, IF = 1.5 A, 30 pulses, f = f0, T = 10 ms )

Output Signal


Ee

t

VO

VOH

VOLt

600 s 600 s

T = 60 ms

Ton Toff

94 8134

Optical Test Signal

Output Signal, ( see Fig.10 )


0.05 0.250

2

4

tp/T – Duty Cycle

0.45

94 8144

0.15 0.35

8

6

E

–

Thr

esho

ld Ir

radi

ance

( m

W/m

)

e m

in2

Figure 9. Sensitivity vs. Duty Cycle

0.1 1 10 100 1000

T

,T

-

Out

put P

ulse

Len

gth

( m

s )

on


10000

94 8151

0.0

0.2

0.4

0.6

0.8

1.0

Ton

Toff


off

Figure 10. Output Pulse Diagram

I –

Sup

ply

Cur

rent

( m

A )

s

Tamb – Ambient Temperature ( °C )94 8150

–30 0 30 600.0

0.2

0.4

0.6

0.8

1.0

90

Vs = 5 V

Figure 11. Supply Current vs. Ambient Temperature

800 900 1000

s

– R

elat

ive

Res

pons

itivi

ty (

% )

rel

– Wavelength ( nm )

1100

94 8154

0.0

0.2

0.4

0.6

0.8

1.0

Figure 12. Spectral Response

TFMS 5..0


5 (6)

x

y

00.4 0.2 0.2 0.4

–30


0.6

94 8152

0.6

0 10–10–20 20

–40

Figure 13. Vertical Directivity ϕy

94 8153

00.4 0.2 0.2 0.4

–30


0.60.6

0 10–10–20 20

–40

Figure 14. Horizontal Directivity ϕx

Dimensions in mm

96 12116

TFMS 5..0


6 (6)

Ozone Depleting Substances Policy Statement

It is the policy of TEMIC TELEFUNKEN microelectronic GmbH to

1. Meet all present and future national and international statutory requirements.

2. Regularly and continuously improve the performance of our products, processes, distribution and operating systemswith respect to their impact on the health and safety of our employees and the public, as well as their impact onthe environment.

It is particular concern to control or eliminate releases of those substances into the atmosphere which are known asozone depleting substances (ODSs).

The Montreal Protocol (1987) and its London Amendments (1990) intend to severely restrict the use of ODSs andforbid their use within the next ten years. Various national and international initiatives are pressing for an earlier banon these substances.

TEMIC TELEFUNKEN microelectronic GmbH semiconductor division has been able to use its policy ofcontinuous improvements to eliminate the use of ODSs listed in the following documents.

1. Annex A, B and list of transitional substances of the Montreal Protocol and the London Amendments respectively

2. Class I and II ozone depleting substances in the Clean Air Act Amendments of 1990 by the EnvironmentalProtection Agency (EPA) in the USA

3. Council Decision 88/540/EEC and 91/690/EEC Annex A, B and C ( transitional substances) respectively.

TEMIC can certify that our semiconductors are not manufactured with ozone depleting substances and do not containsuch substances.

We reserve the right to make changes to improve technical design and may do so without further notice.Parameters can vary in different applications. All operating parameters must be validated for each customer

application by the customer. Should the buyer use TEMIC products for any unintended or unauthorizedapplication, the buyer shall indemnify TEMIC against all claims, costs, damages, and expenses, arising out of,

directly or indirectly, any claim of personal damage, injury or death associated with such unintended orunauthorized use.

TEMIC TELEFUNKEN microelectronic GmbH, P.O.B. 3535, D-74025 Heilbronn, GermanyTelephone: 49 (0)7131 67 2831, Fax number: 49 (0)7131 67 2423

Documents

TFMx IR Detector Photomodules on typenumber/O-R/PHOTOMOD.pdf · Free-Space Data Transmission in the Near Infrared Data transmission in free space places a high interference immunity