Chapter 16 20

BOOK REVIEW IN COMMUNICATIONS Electronic Communications System By Malvino

CHAPTER 16 FREQUENCY EFFECTS

# DEFINITIONS TERMS

1) Type of amplifier designed to amplify AC signals

AC amplifier

2) Type of amplifier designed to amplify DC signals as well as AC signals DC amplifier

3)The capacitance that exist between any connecting wire in a transistor circuits that acts like one plate of a capacitor, and the chassis ground

Stray wiring capacitance

4) The frequency at which the voltage gain is equals 0.707 of its maximum value. Cut-off frequency

5) Half-power frequencies Cut-off frequency

6)The band of frequency of an amplifier that lies between 10 times the lower cut-off frequencies and 0.1 times the upper frequency.

Midband

7)The capacitor that produces the upper cut-off frequency and one that is more important than all others in determining the cut-off frequency.

Dominant capacitor

8)Amplifier that uses direct coupling between amplifier stage. This allows the circuit to amplify all the way sown to 0 Hz. DC amplifier

9) A DC amplifier that has high voltage gain, high input impedance and low output impedance.

Op Amps (operational amplifier)

10) Unit used/ attach when taking logarithm of power gain (G)

Decibel (dB)

11) Decibel power gain

Prepared By : RANIEL P. BABON 45


Often used on data sheets to specify the power gain of devices

12) Defined as the output voltage divided by the input voltage.

Voltage gain (A)A = V out/ Vin

13) 2 useful properties of decibel power gain

Each time the ordinary power gain

increases (decreases) by a factor of 2, the decibel power gain

increases (decreases) by 3 dB.

Each time the ordinary power gain increases

(decreases) by a factor of 10, the decibel power

gain increases (decreases) by 10 dB.

14) Basic rules for voltage gain 2, 6 dB x ordinary10, 20 dB x ordinary

15) Impedance (Z) for microwave system 50 Ω

16) Impedance (Z) for coaxial cable used in TV system 75 Ω

17) Impedance (Z) for twin-lead wire used also in TV system

300 Ω

18) Impedance (Z) used in telephone system 600 Ω

19) Equals to the square of voltage gain in any impedance matched system.

Power gain (G)G = A2

20) Equals to the decibel voltage gain in any impedance matched system

Decibel Power GainG dB = A dB

21) The inverse of logarithm Antilog / (log -1) / (1/log)

22)



Unit used to indicate the power level above 1 mWDecibel (dBm)

P dBm = 10 log [ P / 1 mW ]

23) The unit that can also be used to indicate the voltage level above 1 V

DecibelsV dBV = 20 log [ V/ 1V ]

24)Type of graph that uses decibels and can give us more information about the amplifier response outside the midband.

Bode plots

25)In terms of music , the word that refer to the doubling (x2) of the frequency*The ratio of lower frequency to the upper frequency that uses a factor of 2.

Octaves

26) The word refer to the ratio of lower frequency to the upper frequency that uses a factor of 10.

Decades

27) The scale that has the same space separation for all the numbers

Linear scale

28) The scale wherein the space between numbers are compressed logarithmically

Logarithmic scale

29)A graph paper that has a linear scale on the vertical axis and a logarithmic scale on the horizontal axis

Semi logarithmic

30) A graph that contains all the original information when correction of 3dB is mentally included

Ideal Bode Plot

31)Decreases of 20 dB per decade occur in an amplifier where there is one dominant capacitor producing the :

Lower cutoff frequency

32)Decreases of 20 dB per decade occur in an amplifier where there is one dominant bypass capacitor producing the :

Upper cutoff frequency



33) Another term used by technicians and engineers in industries for “cut-off frequencies”

Corner frequency

34)This term is used because the graph of the Ideal Bode Plot breaks at each cut-off frequency and then decreases at a rate of 20dB per decade

Break frequency

35) It tells you the frequency limitation of an Op Amp Unity-gain frequency

36) Unwanted signals that can appear under certain conditions in most Op Amps

Oscillations

37) The circuit with bypass capacitor and the output voltage lags the input voltage at higher frequency

Lag circuit

38)The charging and discharging of a capacitor produce a ______ in the output voltage of an RC bypass circuit.

Lag

39) An amplifier that produces an output voltage that is 180 o out-of-phase with the input voltage.

Inverting amplifier

40)The capacitor between the input and the output terminals of an amplifier Feedback capacitor

41)This converts the feedback capacitor into two equivalent capacitors, one for the input and one for the output side.

Miller’s theorem

42)The phenomenon wherein the feedback capacitance has been amplified to get a much higher capacitance

Miller effect

43)This means that the operational amplifier includes one dominant bypass capacitor that rolls off the Internally compensated



voltage gain at a rate of 20 dB per decade

44)The circuit on a typical operational amplifier that produces a dominant cut-off frequency. The voltage gain breaks at this cut-off frequency

Input lag circuit

45)In amplifier, this means that we use sinusoidal input voltage and measure the sinusoidal output voltage.

Sin wave testing

46) In DC amplifier, this word refer t all frequencies from zero up to the cut-off frequency.

Bandwidth

47) F2 = 0.35 / TR Risetime bandwidth relationship

48) Unity-gain frequency for most commercially available op amps

1 – over 200 MHz

49) Consider as the heart of the analog system Operational amplifier

50)2 internal capacitance of transistor 1. )collector capacitance

2. )emitter capacitance

51)

3 sources of stray effects

1. ) geometry and internal structure of the device2. ) printed circuit layout, including the orientation of the device and conductive tracks3. ) external leads on



the device

52) Graph of voltage gain versus input frequency Frequency response

53) Defined as 10 times the common logarithm of the power gain

Decibel power gain

54) Capacitors that produces the lower cut-off frequency

Coupling and bypass capacitor

55) Produces the upper cut-off frequency1. ) internal transistor capacitance2. ) stray wiring capacitance

56) Defined as 20 times the common logarithm of the voltage gain.

Decibel voltage gain

CHAPTER 17 DIFFERENTIAL AMPLIFIERS

# DEFINITIONS TERMS

1) Refer to the amplifier that performs a mathematical operation

Operational amplifier

2)It is a complete functional block with external pins IC Op Amps



3) Amplifier design to eliminate the need for an emitter bypass capacitance Differential amplifier

4) Two circuit stages in parallel with a common emitter resistor Differential amplifier

5) Defined as the voltage between the collector with the polarity

AC output voltage (differential output)

6) 2 separate s input of a differential amplifier1. ) non-inverting input2. ) inverting input

7) 2 output of a differential amplifier1. )single-ended output2. )differential output

8)The input voltage on a differential amplifier wherein the output voltage is 180 o out-of-phase with the 2nd input (V2)

Inverting input

9) The input voltage on a differential amplifier wherein the output voltage is still in-phase with the 1st input. Non-inverting input

10) Total input when both the inverting and non-inverting input voltages are present.

Differential input

11) Operation of a differential amplifier wherein one of the inputs is used and the other is grounded.

Single-ended input operation

12) Any change from the quiescent voltage. AC voltage (V out)

13)

3 input characteristics of an operational amplifier.

1. )input bias current2. )input offset current3. )input offset



voltage

14) The input offset current of identical transistors. Zero (0)

15) One way to reduce the output error voltage on the other side of the differential amplifier.

Using an equal base resistance

16)The input voltage that would produce the same output error voltage in a perfect differential amplifier.

Input offset voltage

17) A circuit which should be used if output error voltage is a problem

Nulling circuit

18)The same input voltage being applied to each of the base of a differential amplifier with single-ended output

Common-mode signal

19) Defined as the voltage gain divided by common-mode voltage gain

Common-mode rejection ratio (CMRR)

20) This means components are produced and connected during the manufacturing process on a single chip.

Integrated

21) A small piece of semiconductor materials. Chips

22) The wafer that will be used as a chassis for integrated components.

P-substrate

23) A thin layer of an N-type semiconductor on a heated chemical reaction.

Epitaxial layer

24) Sealing off the surface and prevents further chemical reactions

Passivation

25) Kind of insulation wherein integrated components are insulated from one another.

Depletion-layer insulation



26) A Greek word that means “one stone”. Monolithic

27) The most common type of IC.Monolithic IC

28) Common application of Monolithic IC’s.

1. )amplifier2. )voltage regulator

3. )crowbars4. )AM receivers5. )TV circuits

6. )computer circuits

29) It is used in IC’s because it is a convenient way to create current source and active loads.

Current mirror

30) Refers to fewer than 12 components IC. SSI

31) Refers to between 12 to 100 components IC. MSI

32) Refer to more than 100 components IC. LSI

33) Refers to more than 1000 components IC. VLSI

34) Refer to more than 1000000 components IC ULSI

CHAPTER 18

OPERATIONAL AMPLIFIER

# DEFINITIONS TERMS

1) It has a non-inverting input, an inverting input and a single-ended output

Typical operational amplifier

(op amps)

2)Has an infinite open-loop voltage gain, infinite input resistance and 0 (zero output) impedance Z.

Ideal op amps



3) The 1st stage that determines the input characteristics of the op amps.

Differential amplifier

4) 2 important factors that apply to typical op amps1. )differential input

2. ) single-ended output

5) Refer to ideal op amps that represents a perfect voltage amplifier

Voltage-Controlled Voltage Source (VCVS)

6) Characteristics of an ideal op amps

1. )infinite gain frequency2. )infinite unity-gain3. )infinite input impedance4. )infinite CMRR5. )zero output resistance6. )zero bias current7. )zero offset

7)Used to adjust the overall voltage gain to a much lower value in exchange for stable linear operation. Negative feedback

8) When no feedback paths/loop is used, the voltage gain is maximum.

Open-loop voltage gain

9) It is used in the later stages to get more voltage gains

Bipolar transistors

10) Circuit that produces a cut-off frequency of 10 Hz in an LM741C.

Lag circuit

11)Circuit that uses operational amplifier, resistor, and capacitor to tailor the frequency response for different applications.

Active filters

12)The advantage of using external compensating capacitor.

the designer has more control over the high-



frequency performance

13)A slow change in output caused by the effect of changing temperature on operational amplifier parameters.

Thermal drift

14) Quiescent output voltage of an ideal operational amplifier. 0 V.

15) This is the maximum output current the operational amplifier can produce.

Short circuit output current

16) It is the frequency at which the voltage gain equals to 1.

Unity-gain frequency

17)A capacitor inside operational amplifier that prevents oscillations that would interfere with the desired signal.

Compensating capacitor

18) A sudden transition in voltage from one DC level to a higher DC level.

Voltage step

19) This is equal to the change in output voltage divided by the change in time.

Slew rateSR = ΔV out /Δ t

20)The highest frequency that can be amplified without slew rate distortion.

Power bandwidth / large signal bandwidth of the

op amp

21) 2 bandwidth to consider when analyzing the operation of op amp circuit.

1. small signal bandwidth

determined by the first order

response of the op amp

2. large-signal or power bandwidth

determined by slew rate

22)The most basic operational amplifier circuit that



uses a negative feedback to stabilize the overall voltage gain.

Inverting amplifier

23) A wire between some point in a circuit and ground. Ground to both voltage and current. Mechanical ground

24) The type of ground which is widely used shortcut for analyzing an inverting amplifier. Virtual ground

25) Half-ground quality; short for voltage and open for current.

Virtual ground

26) The voltage where there is a feedback path between output and the input. Closed-loop voltage gain

27) It is equal to the ratio of feedback resistance to the input resistance.

Closed-loop voltage gainACL = R2/R1

28)This reduces the output error caused by input bias current, input offset current, and input offset voltage.

Negative feedback

29) Another basic operational amplifier circuit that uses negative feedback to stabilize the overall voltage gain

Non-inverting amplifier

30) A wire between 2 points in a circuit that is short for both voltage and current.

Mechanical short

31)Type of short that can be used for analyzing non-inverting amplifier short for voltage and open for current.

Virtual short

32)The virtual short uses these two properties of an ideal operational amplifier

1. since Rin is infinite, both input currents are zero 2. since AOL is infinite, V1 – V2 is zero



33) An amplifier used to combine two or more analog signals into a single output Summing amplifier

34) A circuit that combines all the amplified signals into a single output Summing circuit

35) The convenient way of combining audio signals in a high-fidelity system

Using a mixer

36) It is the equivalent of emitter follower, except that this works much better

Voltage follower

37) Is a perfect follower circuit because it produces an output voltage that is equal to the input voltage

Voltage follower

38) Is the ideal interface to use between a high impedance source and a low impedance load. Voltage follower

39) Represents about a third of all linear IC’s Op Amps

40) Other linear IC’s1. audio amplifier2. video amplifier3. voltage regulator

41) This equal to the change in the input offset voltage divided by the change in the supply voltages.

Power Supply Rejection Ratio (PSRR) = ΔV in /Δ

Vs

42) This means that there are either two or four op amps in the same package.

Dual and quad op amps

43) Audio amplifiers with less than 50 mW of output power.

Preamplifier (preamp)

44) Amplifiers that has an output powers from 50 – 500 mW.

Medium-level audio amplifier



45) Amplifier that has a flat response (constant decibel voltage gain) over a broad range of frequencies.

Video/wideband amplifier

46)This have voltage gains and bandwidth that you can adjust by connecting different external resistors.

IC video amplifiers

47) It is usually the 1st stage in an AM, FM or TV receivers.

Radio frequency (RF) amplifier

48) It is usually the middle stage in an AM, FM, or TV receivers.

Intermediate frequency (IF) amplifier

CHAPTER 19 FEEDBACK AMPLIFIER

# DEFINITIONS TERMS

1)Four types of negative feedback

1. ) VCVS (Voltage controlled voltage

source)2. ) ICVS (current controlled voltage

source)3. ) VCIS (voltage controlled current

source)4. ) ICIS (current

controlled current source)

2) Voltage controlled



Type of negative feedback that has input and output voltage and it has a stabilized voltage gain, infinite input impedance, and zero output impedance (ideal voltage amplifier).

voltage source (VSVS)

3)Type of negative feedback that has an input current controls an output voltage, because of this it sometimes called transresistance amplifier.

Current-controlled voltage-source (ICVS)

4) This word is used because the ratio of Vout / Iin has the unit of Ohms (Ω). Resistance

5)This prefix refers that has an input voltage controlling the output current, because of this it sometimes called transconductance amplifier.

Voltage-controlled current source (VSIC)

6) This word is used because the ratio of Iout / Vin has the unit of siemens.

Conductance

7)Type of feedback amplifier wherein the output current is amplified to get a larger output current. (Ideal current amplifier) has stabilized current gain, zero input impedance and infinite output impedance.

Current-controlled current source (ICIS)

8)This type of amplifier is when you put voltage at the input and you get ampere (current) at the output.

Voltage to current converter

9) This amplifier has a voltage output when you input current Current to voltage

converter

10) Defined as feedback voltage divided by the output voltage

Feedback fraction (B)B = V2/ Vout

11)This indicates how much the output voltage is attenuated before the feedback signal reaches the inverting input.

Feedback attenuation factor

12)This means that it almost eliminates the internal operational amplifier variations and makes the closed-loop voltage gain dependent primarily on

Negative feedback stabilizes the voltage

gain



external resistance.

13) It is the voltage gain of the forward and feedback path. Loop gain

14)It depends on having a very low percent error between the ideal and the exact closed-loop voltage gains.

Gain stability

15) Occur when the open-loop voltage gain is minimum. Worst-case error

16) Overall output impedance of a VCVS amplifier. Closed-loop output impedance

17)This occurs in the later stages of amplifier with large signals because the input/output response of the amplifying devices becomes linear. Non-linear distortion

18) The rms value of all the harmonics measured together tells us how much distortion has occurred.

Harmonic distortion

19) The instrument used to measure harmonic distortion Distortion analyzer

20)It acts like a perfect current amplifier, because it has very low input impedance and very high output impedance.

ICIS amplifier

21) The product of gain and bandwidth.Gain Bandwidth Product

(GBP)ACL x f2 = f unity

22) Occurs when voltage input is high enough to saturate one transistor and cut-off the others. Slew rate distortion

23) VCVS prototype with addition of coupling capacitors. AC amplifier



CHAPTER 20 LINEAR OP AMP CIRCUITS

# DEFINITIONS TERMS

1) Variety of basic Linear Op Amp circuits

1. inverting amplifier2. non-inverting amplifier3. differential amplifier4. instrumentation amplifier5. current boosters6. controlled current sources7. automatic gain control circuit

2)1. stable voltage gain



Advantages of non-inverting amplifier 2. high input impedance3. low output impedance

3) A circuit that produces an extremely accurate and stable value of output voltage. Voltage reference

4)This kind of circuit is used in communication receiver to reduce listeners fatigue by having a low voltage gain when no signal is being received. Squelch circuit

5)Circuit in which the input signal drives both inputs of the Op Amps simultaneously and produces the output with superposition of 2 amplified signals.

Inverter/non-inverter circuit

6) A rather unusual circuit because its voltage gain can be varied from -1 to +1.

Sign changer circuit

7) A point when (wiper at center) where a common-mode signal drives the Op Amps and the output is ideally zero.

Crossover point

8) A circuit that allows us to adjust voltage gain between +n to –n. Adjustable and

reversible gain circuit

9) A circuit that can ideally produce a phase shift of 0o to 180o Phase shifter

10)The most important characteristic of differential amplifier because the typical input signal is a small differential voltage and a large common-mode voltage.

CMRR(Common-Mode Rejection Ratio)

11) The desired input voltage of a differential amplifier. Differential input voltage

12) Amplifier often used in applications in which the differential input signal is a small DC voltage (mV). Differential amplifier

13)The voltage gain that distinguish from the common- Differential voltage gain



mode voltage gain.

14)Said to be balanced when the ratio of resistance on the left side equals the ratio of resistance on the right side. R1/R2 = R3/R4.

Wheatstone Bridge

15) A device that converts an electrical quantity into a non-electrical quantity. Output transducer

16) A device that converts a non-electrical quantity into an electrical quantity Input transducer

17) A resistor that converts a change in light intensity into a change in resistance. Photoresistors

18) A resistor that converts a change in temperature into a change in resistance. Thermistors

19) A diode that converts current into light LED

20)A device which converts AC voltage into sound waves Loudspeaker

21) Available quantities for wide variety of transducers

1. temperature2. sound3. light4. humidity5. velocity6. acceleration7. force8. radioactivity9. strain10.pressure

22)A differential amplifier that has a large voltage gain, a high CMRR, low input offsets, low temperature

Instrumentation amplifier



drift and high input impedance.

23) A resistor which has a temperature drift for as low as 1 ppm/oC Precision resistors

24)This is used when building the instrumentation amplifier to have high CMRR and low offset in the input.

Precision Op Amps

25)The technique to minimize the effects of leakage current and cable capacitance, the shield should be bootstrapped to the common-mode potential.

Ground driving

26) The word that refers to a fine adjustment rather than a coarse adjustment. “trim”

27)It means burning off resistor areas on a semiconductor chip with a laser to get an extremely precise value of resistance.

Laser trimming

28)

It is typically have a voltage gain between 1 to 1000 that can be set with 1 external resistor, a CMRR greater than 100 dB, an input impedance greater than 100 MΩ, an input offset voltage less than 0.1 mV., a drift of less than 0.5 μV/ oC and other outstanding parameter.

Monolithic instrumentation

amplifier

29)The circuit that subtract two input voltages to produce an output voltage equal to the difference of two input voltages.

Subtractor

30)A circuit that has inverting and non-inverting inputs. The inverting and non-inverting side has two input channels, and the total gain is the superposition of the channel gains.

Summing amplifier

31) A circuit whose output equals the average of the input voltages. Averager



32)In digital electronics, it is a weighted summing circuit that produced an output equal to the weighted sum of the inputs.

Digital to analog converter

33) Input voltages that have a value either 1 or 0. Digital input voltages

34) A power transistor or other devices that has a current gain and a higher current rating than the Op Amps.

Current boosters

35) It increases the short-circuit output current of the Op Amps.

Unidirectional current boosters

36) It refers to the supply lines of an op-amp because they look like rails on a schematic diagram. Rail-to-rail

37)This means that the input and output voltages van swing all the way to the positive or negative supply voltage.

Rail-to-rail operation

38)In radio or television, this is used to keep the volume from changing abruptly when we tune in different stations.

AGC (Automatic Gain Control)

39) In AGC circuit, the main function of JFET is ______. Voltage controlled

resistance

40) This reduces the power-supply ripple and noise appearing at the non-inverting input. Bypass capacitor

41) This current-source is a bidirectional voltage-controlled current source.

The Howland current source


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Chapter 16 20