This set of Linear Integrated Circuit Multiple Choice Questions & Answers (MCQs) focuses on “Frequency response of internally compensating and non-compensating op-amp”.
1. Open loop bandwidth of an op-amp extend its bandwidth from
a) 0Hz to fo
b) 20dB to fo
c) 3dB to fo
d) 0.704dB to fo
Explanation: The gain of the op-amp remains essentially constant from 0 to the break frequency fo and therefore rolls off at a constant rate of 20dB per decade. Thus, the open-loop bandwidth is the frequency band extending from 0Hz to fo.
2. What happens if 741 op-amp is configured as a closed loop inverting amplifier?
a) Gain increases
b) Gain roll-off at a rate 20dB/decade
c) No gain roll-off takes place
d) Gain decreases
Explanation: Whether the op-amp is inverting / non-inverting the gain will always roll-off at a rate of 20dB/decade, using only resistive components regardless of the value of its closed loop gain.
3. Op-amp requiring external compensating components is called as
a) Tailored frequency response op-amp
b) Compensating op-amp
c) Transient op-amp
d) High frequency op-amp
Explanation: Op-amp using external components like resistor and capacitor to form the compensating network are sometimes called tailored frequency response op-amps because the user has to provide the compensation if it is needed to tailor the response.
4. In the first generation op-amp 709c, the open loop bandwidth of gain versus frequency curve
a) Increases from the innermost compensated curve to the outermost
b) Decrease from the innermost compensated curve to the outermost
c) Increases from the outermost compensated curve to the innermost
d) Decreases from the outermost compensated curve to the innermost
Explanation: The gain versus frequency curve of 709c decreases from the outermost compensated curve to the innermost. For example, if C1 =10pF, R1 = 0Ω and C2 = 3pF, the bandwidth ≅ 5kHz. While if C1 =5000pF, R1 =1.5Ω and C2= 200pF, the bandwidth will be 100Hz.
5. Which type of op-amp offer relatively broader open-loop bandwidth?
a) Compensated op-amp
b) Uncompensated op-amp
c) Tailored frequency response op-amp
d) Non-compensated op-amp
Explanation: The uncompensated op-amps offer broader open loop bandwidth whereas; the internally compensated op-amps have very small open-loop bandwidth.
Sanfoundry Global Education & Learning Series – Linear Integrated Circuit.