Sd292 Asg3

SYDE 292

Sample Exam Questions

#3

Questions: 1. Show that the circuit shown below has a first order low-pass transfer function. For the case R1 = 1 kΩ, R2 = 100 kΩ and C2 = 100 pF, find the DC gain and the 3-dB frequency. Show all calculations. Assume that the op-amp is ideal.

Vo ( jw) for the non-inverting amplifier. Vi ( jw) Assume that the op-amp is an LF356 and that only the open loop gain is non-ideal. Provide a gain dB versus frequency plot when R2 = R1.

2. Derive the transfer function

Note: The spec sheets for the LF356 op-amp have be issued. This is the op-amp used in the laboratory. 3. Verify analytically that the gain bandwidth product of both the inverting and noninverting amplifier is a constant. (Hint: this is really quite straight forward - don't complicate it) 4. Derive the gain for the inverting amplifier and the voltage follower when the op-amp has a finite CMRR. Vo of the amplifier circuit shown below left. Vi Hint: Start at the left hand side of the feedback circuit and work your way toward the output figuring out the various node voltages and branch currents in the feedback circuit.

5. Find the gain

6. For the circuit shown above right, express Vo as a function of V1 and V2. 7. What is the gain as a function of x for the circuit shown below left.

8. For the circuit shown above right, determine the output voltage for each of the following combinations of input voltages; a) V1 = 3V, V2 = 2V; b) V1 = 3V, V2 = -4V ; c) V1 = 5V, V2 = -8V. d) V1 = -5V, V2 = -8V. Assume that +/- Vsat = +/- 13V. 9. The circuit shown below left is a Howland voltage controlled current source, show that iL = Vin / R as long as ILRL < Vsat / 2

10. The circuit shown above right is a current controlled current source show that iL = G iin with G = (1 + R2 / R1)