LT1797 – 10MHz, Rail-to-Rail Input and Output Op Amp in SOT …LT1797 1 1797fc For more information Typical applicaTion FeaTures DescripTion 10MHz, Rail-to-Rail Input and Output

LT1797

11797fc

For more information www.linear.com/LT1797

Typical applicaTion

FeaTures DescripTion

10MHz, Rail-to-RailInput and Output

Op Amp in SOT-23

The LT®1797 is a unity-gain stable 10MHz op amp available in the small SOT-23 package that operates on all single and split supplies with a total voltage of 2.7V to 12V. The amplifier draws 1mA of quiescent current and has a slew rate of 2.25V/µs.

The input common mode range of the LT1797 includes both rails, making it ideal for current sensing applications. The input stage incorporates phase reversal protection to prevent false outputs from occurring when the inputs are driven beyond the supplies. Protective resistors are included in the input leads so that current does not become excessive when the inputs are forced above or below the supplies.

The output of the LT1797 can swing to within 50mV of V+ and 8mV of V– without drawing excess current in either condition. The amplifier can drive loads up to 25mA and still maintain rail-to-rail capability.

The LT1797 op amp is available in the space saving 5-lead SOT-23 package.L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and ThinSOT and Over-The-Top are trademarks of Analog Devices, Inc. All other trademarks are the property of their respective owners.

Fast Compact –48V Current Sense

applicaTions

n Rail-to-Rail Input and Outputn Small SOT-23 Packagen Gain Bandwidth Product: 10MHzn –40°C to 85°C Operationn Slew Rate: 2.25V/µsn Low Input Offset Voltage: 1.5mV Maxn High Output Current: 25mA Minn Specified on 3V, 5V and ±5V Suppliesn High Voltage Gain: 1000V/mV 10k Loadn High CMRR: 96dB Typn High PSRR: 90dB Typn Input Bias Current: 300nA Maxn Input Offset Current: 25nA Maxn Low Profile (1mm) SOT-23 (ThinSOT™) Package

n Portable Instrumentationn Rail-to-Rail Buffer Amplifiersn Low Voltage Signal Processingn Driving A/D Convertersn Battery-Powered Systems

Small-Signal Response

–

+LT1797

0.1µF

R1 REDUCES Q1 DISSIPATION

Q1FMMT493

0.003Ω1% 3W

BZX84C6V8VZ = 6.8V

–48V SUPPLY(–42V TO –56V)

3.3k0805×3

30.1Ω1%

ISENSE+–

R14.7k

VS = 3V

1k1%

VOUT = 3V – 0.1Ω • ISENSEISENSE = 0A TO 30AACCURACY ≈ 3%

–48V LOAD1797 TA01

SETTLES TO 1% IN 2µs,1V OUTPUT STEP

VOUT

1797 TA01b

VS = ±2.5VAV = 1RL = 10k

http://www.linear.com/LT1797


LT1797

21797fc


pin conFiguraTionabsoluTe MaxiMuM raTings

Total Supply Voltage (V+ to V–) .............................. 12.6VInput Differential Voltage ....................................... 12.6VInput Current ........................................................ ±10mAOutput Short-Circuit Duration (Note 2) ........ ContinuousOperating Temperature Range (Note 3) ....–40°C to 85°CSpecified Temperature Range ..................–40°C to 85°CJunction Temperature ........................................... 150°CStorage Temperature Range .................. –65°C to 150°CLead Temperature (Soldering, 10 sec) ................... 300°C

(Note 1)

4

5

3

1 OUT

V–

+IN

V+

–IN

TOP VIEW

S5 PACKAGE5-LEAD PLASTIC TSOT-23

2 + –

TJMAX = 150°C, θJA = 250°C/W

orDer inForMaTionLEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE

LT1797CS5#PBF LT1797CS5#TRPBF LTLM 5-Lead Plastic TSOT-23 –40°C to 85°C

LT1797IS5#PBF LT1797IS5#TRPBF LTTL 5-Lead Plastic TSOT-23 –40°C to 85°C

Consult LTC Marketing for parts specified with wider operating temperature ranges.For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/. Some packages are available in 500 unit reels through designated sales channels with #TRMPBF suffix.

elecTrical characTerisTics The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = 3V, 0V; VS = 5V, 0V, VCM = VOUT = half supply, pulse power tested, unless otherwise specified. (Note 3)

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

VOS Input Offset Voltage 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C

l

l

1 1.5 2.5 3.0

mV mV mV

Input Offset Voltage Drift (Note 4) l 5 20 µV/°C

IB Input Bias Current VCM = V– VCM = V+

l

l

–300 –150 50

100

nA nA

Input Bias Current Drift l 0.1 nA/°C

IOS Input Offset Current VCM = V– VCM = V+

l

l

10 10

25 25

nA nA

Input Noise Voltage 0.1Hz to 10Hz 1.5 µVP-P

en Input Noise Voltage Density f = 10kHz 20 nV/√Hz

in Input Noise Current Density f = 10kHz f = 10kHz, VCM = VCC – 0.3V

0.23 0.15

pA/√Hz pA/√Hz

RIN Input Resistance Differential Common Mode, VCM = 0V to VS – 1.3V

200 330 100

kΩ MΩ

CIN Input Capacitance 4 pF

CMRR Common Mode Rejection Ratio VCM = 0V to VS – 1.3V VS = 5V, VCM = 0V to 5V VS = 3V, VCM = 0V to 3V

l

l

l

82 64 60

96 72 68

dB dB dB

http://www.linear.com/product/LT1797#orderinfo


http://www.linear.com/leadfree/

http://www.linear.com/tapeandreel/

http://www.linear.com/product/LT1797#orderinfo

LT1797

31797fc


elecTrical characTerisTics The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = 3V, 0V; VS = 5V, 0V, VCM = VOUT = half supply, pulse power tested, unless otherwise specified. (Note 3)


Input Voltage Range l 0 VS V

AVOL Large-Signal Voltage Gain VS = 3V, VO = 0.5V to 2.5V, RL = 10k

l

200 150

1000 V/mV V/mV

VS = 5V, VO = 0.5V to 4.5V, RL = 10k

l

400 300

1000 V/mV V/mV

PSRR Power Supply Rejection Ratio VS = 2.7V to 12V, VCM = VO = 1V l 80 90 dB

Minimum Supply Voltage l 2.5 2.7 V

VOL Output Voltage Swing LOW No Load, Input Overdrive = 30mV ISINK = 5mA ISINK = 10mA

l

l

l

8 80

150

30 160 250

mV mV mV

VOH Output Voltage Swing HIGH No Load, Input Overdrive = 30mV ISOURCE = 5mA ISOURCE = 10mA, VS = 5V ISOURCE = 10mA, VS = 3V

l

l

l

l

VS – 0.14 VS – 0.30 VS – 0.39 VS – 0.59

VS – 0.05 VS – 0.2 VS – 0.3 VS – 0.3

V V V V

ISC Short-Circuit Current VS = 5V VS = 3V

25 15

45 25

mA mA

IS Supply Current

l

1.1 1.5 2.0

mA mA

GBW Gain Bandwidth Product (Note 5) f = 100kHz 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C

l

l

6.0 5.0 4.5

10 MHz MHz MHz

SR Slew Rate (Note 5) AV = –1 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C

l

l

1.3 1.1 1.0

2.25 V/µs V/µs V/µs

tr Output Rise Time 10% to 90%, 0.1V Step, RL = 10k 55 ns

tf Output Fall Time 10% to 90%, 0.1V Step, RL = 10k 55 ns

tS Settling Time VS = 5V, ΔVOUT = 2V to 0.1%, AV = –1 1.6 µs

THD Distortion VS = 3V, VOUT = 1.8VP-P, AV = 1, RL = 10k, f = 1kHz 0.001 %

FPBW Full-Power Bandwidth (Note 6) VOUT = 2VP-P 360 kHz

The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = ±5V, VCM = 0V, VOUT = 0V, pulse power tested unless otherwise specified. (Note 3)


VOS Input Offset Voltage 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C

l

l

1 1.5 2.5 3.0

mV mV mV

Input Offset Voltage Drift (Note 4) l 5 20 µV/°C

IB Input Bias Current VCM = V– VCM = V+

l

l

–300 –150 50

100

nA nA

Input Bias Current Drift l 0.1 nA/°C

IOS Input Offset Current VCM = V– VCM = V+

l

l

10 10

25 25

nA nA

Input Noise Voltage 0.1Hz to 10Hz 1 µVP-P

en Input Noise Voltage Density f = 10kHz 20 nV/√Hz

in Input Noise Current Density f = 10kHz f = 10kHz, VCM = 4.7V

0.23 0.15

pA/√Hz pA/√Hz


LT1797

41797fc


elecTrical characTerisTics The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.VS = ±5V, VCM = 0V, VOUT = 0V, pulse power tested unless otherwise specified. (Note 3)


RIN Input Resistance Differential Common Mode, VCM = –5V to 3.7V

200 330 100

kΩ MΩ

CIN Input Capacitance 4 pF

Input Voltage Range l –5 5 V

CMRR Common Mode Rejection Ratio VCM = –5V to 3.7V VCM = –5V to 5V

l

l

78 66

96 76

dB dB

AVOL Large-Signal Voltage Gain VO = ±4V, RL = 10k

l

400 300

1000 V/mV V/mV

VOL Output Voltage Swing LOW No Load, Input Overdrive = 30mV ISINK = 5mA ISINK = 10mA

l

l

l

–4.99 –4.92 –4.85

–4.97 –4.87 –4.79

V V V

VOH Output Voltage Swing HIGH No Load, Input Overdrive = 30mV ISOURCE = 5mA ISOURCE = 10mA

l

l

l

4.84 4.70 4.61

4.95 4.80 4.70

V V V

ISC Short-Circuit Current (Note 2) Short to GND 30 50 mA

PSRR Power Supply Rejection Ratio VS = ±1.35V to ±6V l 80 90 dB

IS Supply Current

l

1.40 2.25 3.00

mA mA

GBW Gain Bandwidth Product f = 100kHz 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C

l

l

6.5 5.5 5.0

11 MHz MHz MHz

SR Slew Rate AV = –1, RL = ∞, VO = ±4V, Measured at VO = ±2V 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C

l

l

1.50 1.25 1.10

2.50 V/µs V/µs V/µs

tr Output Rise Time 10% to 90%, 0.1V Step, RL = 10k 55 ns

tf Output Fall Time 10% to 90%, 0.1V Step, RL = 10k 55 ns

tS Settling Time ΔVOUT = 4V to 0.1%, AV = 1 2.6 µs

FPBW Full-Power Bandwidth (Note 6) VOUT = 8VP-P 100 kHz

Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime.Note 2: A heat sink may be required to keep the junction temperature below absolute maximum.

Note 3: The LT1797C is guaranteed to meet 0°C to 70°C specifications and is designed, characterized and expected to meet the extended temperature limits, but is not tested at –40°C and 85°C. The LT1797I is guaranteed to meet specified performance from –40°C to 85°C.Note 4: This parameter is not 100% tested.Note 5: VS = 3V limit guaranteed by correlation to 5V tests.Note 6: Full-power bandwidth is calculated from the slew rate: FPBW = SR/2πVP


LT1797

51797fc


Output Saturation Voltagevs Load Current (Output High)

Output Saturation Voltagevs Load Current (Output Low)

Output Saturation Voltagevs Input Overdrive

Output Short-Circuit Currentvs Temperature 0.1Hz to 10Hz Noise Voltage

Input Noise Voltage Densityvs Frequency

Supply Current vs Supply Voltage Minimum Supply VoltageInput Bias Current vs Common Mode Voltage

Typical perForMance characTerisTics

TOTAL SUPPLY VOLTAGE (V)0

0

SUPP

LY C

URRE

NT (m

A)

0.2

0.6

0.8

1.0

6 7 8 9

1.8

1797 G01

0.4

1 2 3 4 5 10 11 12

1.2

1.4

1.6 TA = 125°C

TA = 25°C

TA = –55°C

TOTAL SUPPLY VOLTAGE (V)

–300

INPU

T OF

FSET

VOL

TAGE

CHA

NGE

(µV)

–100

100

300

–200

0

200

1.0 1.5 2.0 3.0 4.0

1797 G02

5.00.50 2.5 3.5 4.5

TA = 125°CTA = –55°CTA = 25°C

COMMON MODE VOLTAGE (V)

–200

INPU

T BI

AS C

URRE

NT (n

A)

–100

0

100

–150

–50

50

1.0 2.0 3.0 4.0

1797 G03

5.00.50 1.5 2.5 3.5 4.5

VS = 5V, 0V

TA = 25°CTA = 125°C

TA = –55°C

SOURCING LOAD CURRENT (A)1µ

0.01

OUTP

UT S

ATUR

ATIO

N VO

LTAG

E (V

)

0.1

1

100µ10µ 10m1m

1797 G04

VS = ±2.5VVOD = 30mV

TA = 25°C

TA = 125°C

TA = –55°C

INPUT OVERDRIVE (mV)0

OUTP

UT S

ATUR

ATIO

N VO

LTAG

E (m

V)

60

80

100

120

140

30 50 100

1797 G06

40

20

0

70

90

110

130

150

50

30

10

10 20 40 60 70 80 90

VS = ±2.5VIOUT = 0

OUTPUT HIGH

OUTPUT LOW

SINKING LOAD CURRENT (A)

0.01

OUTP

UT S

ATUR

ATIO

N VO

LTAG

E (V

)

0.1

1µ 100µ 1m 10m

1797 G05

0.00110µ

1

TA = 125°C

VS = ±2.5VVOD = 30mV

TA = 25°C

TA = –55°C

TEMPERATURE (°C)–50

OUTP

UT C

URRE

NT (m

A)

40

45

50

25 75

1797 G07

35

30

–25 0 50 100 125

25

20

VS = ±2.5V

SOURCING CURRENT

SINKING CURRENT

TIME (SEC)

NOIS

E VO

LTAG

E (1

µV/D

IV)

2 4 6 8

1797 G08

1010 3 5 7 9

VS = ±5V

FREQUENCY (Hz)

20

INPU

T NO

ISE

VOLT

AGE

DENS

ITY

(nV/

√Hz)

40

60

80

100

10 1k 10k 100k

1797 G09

0100

VS = ±2.5V


LT1797

61797fc



Slew Rate vs TemperatureGain Bandwidth Product and Phase Margin vs Supply Voltage

PSRR vs Frequency CMRR vs Frequency

Gain Bandwidth Product and Phase Margin vs RF and RG

Output Impedance vs Frequency

Input Noise Current Density vs Frequency

Gain and Phase Shift vs Frequency

Gain Bandwidth Productvs Temperature

FREQUENCY (Hz)

INPU

T NO

ISE

CURR

ENT

DENS

ITY

(pA/

√Hz)

10 1k 10k 100k

1797 G10

100

VS = ±2.5V1.2

1.0

0.8

0.6

0.4

0.2

0

FREQUENCY (Hz)

0

GAIN

(dB)

PHASE (DEG)

60

70

–10

–20

50

20

40

30

10

10k 1M 10M 100M

1797 G11

–30

–40

80

100

–60

–80

60

0

40

20

–20

–100100k

VS = ±2.5V

PHASE

GAIN

TEMPERATURE (°C)–50

GAIN

BAN

DWID

TH P

RODU

CT (M

Hz) 11.5

25

1797 G12

10.0

9.0

–25 0 50

8.5

8.0

12.0

11.0

10.5

9.5

75 100 125

VS = ±5V

VS = ±2.5V

f = 100kHz

TEMPERATURE (°C)–50 –25

1.0

SLEW

RAT

E (V

/µs)

2.0

3.5

0 50 75

1797 G13

1.5

3.0

2.5

25 100 125

RISING

FALLING

VS = ±2.5V

TOTAL SUPPLY VOLTAGE (V)0

8

GAIN

BAN

DWID

TH P

RODU

CT (M

Hz)

PHASE MARGIN (DEG)

10

12

9

11

13

2 4 6 8

1797 G14

101 3 5 7 9 11 12

35

30

45

55

40

50

60

PHASE MARGIN

GAIN BANDWIDTH PRODUCT

f = 100kHzRF = RG = 1k

RF = RG = (Ω)1k

10

GAIN

BAN

DWID

TH P

RODU

CT (M

Hz)

PHASE MARGIN (DEG)

12

14

10k 100k

1797 G15

11

13

20

40

60

10

30

50

PHASE MARGIN

GAIN BANDWIDTH PRODUCT

VS = ±5V

FREQUENCY (Hz)

20

POW

ER S

UPPL

Y RE

JECT

ION

RATI

O (d

B) 80

90

10

0

70

40

60

50

30

1k 100k 1M 10M

1797 G16

–1010k

VS = ±2.5V

NEGATIVE SUPPLY

POSITIVE SUPPLY

FREQUENCY (Hz)

40

COM

MON

MOD

E RE

JECT

ION

RATI

O (d

B) 100

110

30

20

90

60

80

70

50

1k 100k 1M 10M

1797 G17

1010k

VS = ±2.5V

FREQUENCY (Hz) 100 1k

0.01

OUTP

UT IM

PEDA

NCE

(Ω)

1

100

10k 100k 1M 10M

1797 G18

0.1

10GAIN = 100

GAIN = 10

VS = ±2.5V


LT1797

71797fc



Undistorted Output Swingvs Frequency

Total Harmonic Distortion + Noisevs Frequency

Total Harmonic Distortion + Noisevs Load Resistance

Total Harmonic Distortion + Noisevs Output Voltage Amplitude Large-Signal Response Small-Signal Response

Open-Loop GainSettling Time to 0.1% vs Output Step

Capacitive Load Handling Overshoot vs Capacitive Load

OUTPUT VOLTAGE (V)–5

CHAN

GE IN

INPU

T OF

FSET

VOL

TAGE

(50µ

V/DI

V)

1797 G19

–4 –3 –2 –1 0 1 2 3 4 5

VS = ±5V

RL = 50k

RL = 2kRL = 10k

SETTLING TIME (µs)1.0

OUTP

UT S

TEP

(V)

4

3

2

1

0

–1

–2

–3

– 42.6

1797 G20

1.4 1.8 2.2 3.02.41.2 1.6 2.0 2.8

AV = 1

AV = 1

AV = –1

VS = ±5V

AV = –1

CAPACITIVE LOAD (pF)10

20

OVER

SHOO

T (%

)

25

30

35

40

100 1000 10000

1797 G21

15

10

5

0

45

50

AV = 1

AV = 5

AV = 10

AV = 2

VS = ±2.5V

FREQUENCY (Hz)

2

OUTP

UT S

WIN

G (V

P-P)

4

6

8

10

100 10k 100k 1M

1797 G22

01k

12

1

3

5

7

9

11AV = 1

VS = ±5V

VS = ±1.5V

FREQUENCY (Hz) 10 100

0.0001

THD

+ NO

ISE

(%)

0.01

1

1k 10k 100k

1797 G23

0.001

0.1

AV = –1

AV = 1

RL = 10kVS = 3V, 0VVOUT = 1.8VP-PVCM = 1V

LOAD RESISTANCE TO GROUND (kΩ)

0.01

THD

+ NO

ISE

(%)

0.1

1

10

1 10 100

1797 G24

0.0010.1

VS = 3V, 0VVIN = 1.8VP-PVCM = 1.5V

VS = 3V, 0VVIN = 1.8VP-P

VCM = 1V

VS = 3V TOTALAV = 1f = 1kHz

OUTPUT VOLTAGE (VP-P)

0.01

THD

+ NO

ISE

(%)

1

10

0 2 3

1797 G25

0.0011

0.1

f = 1kHzVCM = HALF SUPPLYRL = 10k

AV = –1VS = 3V, 0V

AV = 1VS = 3V, 0V

AV = –1VS = ±1.5V

AV = 1VS = ±1.5V

1797 G26

VS = ±2.5VAV = 1

1797 G27

VS = ±2.5VAV = 1RL = 10k


LT1797

81797fc


applicaTions inForMaTionSupply Voltage

The positive supply pin of the LT1797 should be bypassed with a small capacitor (about 0.1µF) within an inch of the pin. When driving heavy loads an additional 4.7µF electro-lytic capacitor should be used. When using split supplies the same is true for the negative supply pin.

Inputs

The LT1797 is fully functional for an input signal range from the negative supply to the positive supply. Figure 1 shows a simplified schematic of the amplifier. The input stage consists of two differential amplifiers, a PNP stage Q3/Q4 and an NPN stage Q1/Q2 that are active over dif-ferent ranges of input common mode voltage. The PNP differential pair is active for input common mode voltages VCM between the negative supply to approximately 1.3V below the positive supply. As VCM moves closer toward the positive supply, the transistor QB1 will steer the tail current I1 to the current mirror Q5/Q6, activating the NPN differential pair and the PNP pair becomes inactive for the rest of the input common mode range up to the positive supply.

The input offset voltage and the input bias current are dependent on which input stage is active. The input offset voltage is trimmed on a single 5V supply with the common mode at 1/2 supply and is typically 1mV with the PNP stage active. The input offset of the NPN stage is untrimmed and is typically 1.5mV. The input bias current polarity depends on the input common mode voltage. When the PNP dif-ferential pair is active, the input bias currents flow out of the input pins. They flow in the opposite direction when the NPN input stage is active. The offset error due to the input bias currents can be minimized by equalizing the noninverting and inverting source impedance.

The input stage of the LT1797 incorporates phase reversal protection to prevent false outputs from occurring when the inputs are driven up to 5V beyond the rails. Protective resistors are included in the input leads so that current does not become excessive when the inputs are forced beyond the supplies or when a large differential signal is applied.

Output

The output is configured with a pair of complementary common emitter stages Q19/Q20, which enable the output to swing from rail-to-rail. The output voltage swing of the LT1797 is affected by input overdrive as shown in the Typi-cal Performance Characteristics. When monitoring input voltages within 50mV of V+ or within 8mV of V–, some gain should be taken to keep the output from clipping. The output of the LT1797 can deliver large load currents; the short-circuit current limit is typically 50mA at ±5V. Take care to keep the junction temperature of the IC below the absolute maximum rating of 150°C. The output of the amplifier has reverse biased diodes to each supply. If the output is forced beyond either supply, unlimited current will flow through these diodes.

The LT1797 can drive capacitive loads up to 200pF on a single 5V supply in a unity gain configuration. When there is a need to drive larger capacitive loads, a resistor of a couple hundred ohms should be connected between the output and the capacitive load. The feedback should still be taken from the output so that the resistor isolates the capacitive load to ensure stability. The low input bias current of the LT1797 makes it possible to use high value feedback resistors to set the gain. However, care must be taken to insure that the pole formed by the feedback resistors and the total capacitance at the inverting input does not degrade stability.


LT1797

91797fc


applicaTions inForMaTionDistortion

There are two main contributors to distortion in op amps: output crossover distortion as the output transitions from sourcing to sinking current and distortion caused by non-linear common mode rejection. If the op amp is operating in the inverting mode, there is no common mode induced distortion. If the op amp is operating in the PNP input stage (input is not within 1.3V of V+), the CMRR is very good,

typically 96dB. When the LT1797 switches between input stages there is significant nonlinearity in the CMRR. Lower load resistance increases the output crossover distortion, but has no effect on the input stage transition distortion. For lowest distortion the LT1797 should be operated single supply, with the output always sourcing current and with the input voltage swing between ground and (V+ – 1.3V). See the Typical Performance Characteristic curves.

1797 F01

Q18

Q1

Q3 Q4

QB1

Q7

Q11

Q13

Q9

Q6

Q2

Q12

Q8

Q14

Q10

Q5

Q17

Q15

Q19

Q20

Q16R1

R3 R4

R7 R8

R5

R6

R2

D1 D2

–IN

+IN

BIAS

I1

OUT

+1 +1 CM

C1

C2

I3I2

I4 I5

I6

I7

1/2 SUPPLY

Figure 1. Simplified Schematic


LT1797

101797fc


Typical applicaTions

Single Supply Hi-Gain 80kHz Photodiode Amplifier

–

+LT1797

3V

3V

R21k

R41k

R5100k

R6330Ω

R310k

R1100k

C10.1µF

C20.1µF

C31000pF

CP*

1797 TA02

*CP = SUM OF PHOTODIODE CAPACITANCE, PARASITIC LAYOUT CAPACITANCE AND LT1797 INPUT CAPACITANCE ≅10pF.

TRANSIMPEDANCE GAIN: AZ = 10MΩ.

R6, C3 LIMIT THE NOISE BANDWIDTH TO 500kHz.

OUTPUT NOISE ≅1.8mVRMS.

R1, CP AND LT1797 GBW SET UPPER LIMIT ON BANDWIDTH.

R4, C2 SET LOWER 1.6kHz LIMIT ON GAIN OF 101.

PHOTODIODESFH213FA


LT1797

111797fc


Typical applicaTions

Ultralow Noise, ±5V Supply, Rail-to-Rail Output Amplifier

–

+–

+

R110k

R51k

R34.99k

R24.99k

–5V

–5V

5V

5V

LT1028

LT1797

IN

OUT

C12200pF

R410Ω

1797 TA03

TOTAL INPUT VOLTAGE NOISE ≅ 0.94nV/√Hz (INCLUDING 10Ω RESISTOR)

BANDWIDTH ≅ 40kHz

AV = 500


LT1797

121797fc


package DescripTion

1.50 – 1.75(NOTE 4)2.80 BSC

0.30 – 0.45 TYP 5 PLCS (NOTE 3)

DATUM ‘A’

0.09 – 0.20(NOTE 3) S5 TSOT-23 0302

PIN ONE

2.90 BSC(NOTE 4)

0.95 BSC

1.90 BSC

0.80 – 0.90

1.00 MAX0.01 – 0.100.20 BSC

0.30 – 0.50 REF

NOTE:1. DIMENSIONS ARE IN MILLIMETERS2. DRAWING NOT TO SCALE3. DIMENSIONS ARE INCLUSIVE OF PLATING4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR5. MOLD FLASH SHALL NOT EXCEED 0.254mm6. JEDEC PACKAGE REFERENCE IS MO-193

3.85 MAX

0.62MAX

0.95REF

RECOMMENDED SOLDER PAD LAYOUTPER IPC CALCULATOR

1.4 MIN2.62 REF

1.22 REF

S5 Package5-Lead Plastic TSOT-23

(Reference LTC DWG # 05-08-1635)

Please refer to http://www.linear.com/product/LT1797#packaging for the most recent package drawings.


LT1797

131797fc


Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.

revision hisToryREV DATE DESCRIPTION PAGE NUMBER

B 6/10 Updated the last Feature.Updated the package description in the Pin Configuration section.Updated VOH in the Electrical Characteristics section.Replaced the package drawing in the Package Description section.

123

12

C 7/17 Corrected Simplified Schematic 9

(Revision history begins at Rev B)


LT1797

141797fc

For more information www.linear.com/LT1797 LINEAR TECHNOLOGY CORPORATION 2000

LT 0717 REV C • PRINTED IN USAwww.linear.com/LT1797

relaTeD parTs

Typical applicaTion1MHz Photodiode Transimpedance Amplifier Response of Photodiode Amplifier

Rise Time vs Supply Voltage (600mV Output Step)Supply Voltage 10% to 90% Rise Time

±1.5V 830ns

±2.5V 800ns

±5V 700ns

PART NUMBER DESCRIPTION COMMENTS

LT1630/LT1631 Dual/Quad 30MHz, 10V/µs Rail-to-Rail Input and Output Op Amps

High DC Accuracy, 525µV VOS(MAX), 70mA Output Current, Max Supply Current 4.4mA per Amp

LT1638/LT1639 Dual/Quad 1.2MHz, 0.4V/µs, Over-The-Top™ Micropower Rail-to-Rail Input and Output Op Amps

170µA Supply Current, Single Supply Input Range –0.4V to 44V, Rail-to-Rail Input and Output

LT1783 Micropower Over-The-Top SOT-23 Rail-to-Rail Input and Output Op Amp

SOT-23 Package, Micropower 220µA per Amplifier, Rail-to-Rail Input and Output, 1.2MHz Gain Bandwidth

LT1880 SOT-23 Rail-to-Rail Output, Picoamp Input Current Precision Op Amp

150µV Maximum Offset Voltage, 900pA Maximum Bias Current, 1.1MHz Gain Bandwidth, –40°C to 85°C Temperature Range

–

+LT1797

PHOTODIODESFH213FA

SIEMENS/INFINEONVS = ±1.5V TO ±5V

3pF

100k

V+

V–1797 TA04 1797 TA04b2µs/DIV

100mV/DIV









Documents

LT1797 – 10MHz, Rail-to-Rail Input and Output Op Amp in SOT …LT1797 1 1797fc For more information Typical applicaTion FeaTures DescripTion 10MHz, Rail-to-Rail Input and Output