Lab 9: Op Amps II (points per section given in parentheses)
9–1. Op-amp Limitations (34)
(a) Circuit diagram for measuring slew rate (1)
(b) Square wave input: measurements of rising- and falling-edge slew rates for 411 and
741 op amps at vin = 5, 10, and 20 Vpp with supporting scope images (6)
(c) Comparison of 411 and 741 average slew rates with typical values (1)
(d) Comparison of the rising-edge and falling-edge slew rates (2)
(e) Is slew rate amplitude dependent? (1)
(f) Sine input: comparison of measured and predicted frequencies when vout begins to
drop and/or distortion is evident for 411 and 741 at vin = 5, 10, and 20 Vpp with
supporting scope images (6)
(g) Circuit diagram for offset measurements (1)
(h) Measurement of total input offset voltage (2)
(i) What did you do with the “in” terminal to make effects of IB negligible? Why? (3)
(j) Measured Vos, comparison with specs (2)
(k) Explanation of how 10k input resistor allows you to measure IB (2)
(l) Measured IB, comparison with specs (2)
(m) Circuit used to measure Ios with explanation (3)
(n) Measured Ios, comparison with specs (2)
9–2. Integrator (16)
(a) Circuit diagram (1)
(b) Scope image of vin vs. vout for 2 Vpp, 500 Hz square wave input (1)
(c) Measured vs. expected vout (4)
(d) What is the function of the 10 MΩ resistor? What happens if you remove it? (4)
(e) How sensitive is the average DC offset at the output to changes in the DC offset of
the function generator with and without the 10 MΩ resistor? Can you quantify it
when the 10 MΩ resistor is in place? (6)
9–3. Differentiator (16)
(a) Circuit diagram (1)
(b) Scope image of vin vs. vout for 2 Vpp, 1 kHz triangle wave input (1)
(c) Measured vs. expected vout (4)
(d) Are the slew rate limitations of the op amp evident? (2)
(e) Scope image of vin vs. vout for 2 Vpp, 1 kHz sine wave input (1)
(f) Measured vs. expected vout (4)
(g) Measurement of phase difference between vout and vin; is it what you expect? (3)
9–5. Active Rectifier (11)
(a) Circuit diagram (1)
(b) Scope image of vin vs. vout for 10 Vpp sine wave input at 100 Hz, 1 kHz, 10 kHz (3)
(c) Scope image of vout vs. op-amp output for 10 Vpp, 10 kHz sine wave input (1)
(d) What causes the “glitch”? (4)
(e) What happens at higher input frequencies? (2)
Bonus: Measured vs. predicted amplitude of the glitch
9–6. Improved Active Rectifier (7)
(a) Circuit diagram (1)
(b) Scope image of vin vs. vout for 10 Vpp sine wave input at 10 kHz (1)
(c) Scope image of vin vs. op-amp output for 10 Vpp sine wave input at 10 kHz (1)
(d) Explanation of improved performance (4)
Bonus: Measured vs. predicted amplitude of the glitch
9–7. Active Clamp (16)
(a) Circuit diagram (1)
(b) Discussion about the output impedance of this circuit (4)
(c) Scope image of vin vs. vout for a 1 kHz sine wave input (1)
(d) Scope image of vin vs. vout for a 20 kHz sine wave input (1)
(e) What causes the “glitch”? (4)
Bonus: Measured vs. predicted amplitude of the glitch
(f) Scope image of vin vs. vout for a 1 kHz sine wave input with the diode reversed (1)
(g) Explanation of what happens when the diode is reversed (4)