Chapter Questions
Name the five basic terminals of an op amp.
Name the manufacturer of an AD74I op amp.
A $74 \mathrm{l}$ op amp is manufactured in an 8-pin dual-in-line package. What are the terminal numbers for the (a) inverting input; (b) noninverting input; (c) output?
A 741 op amp is connected to a $\pm 15-\mathrm{V}$ supply. What are the output terminal's operating limits under normal conditions with respect to (a) output voltage; (b) output current?
When the load resistor of an op amp is short-circuited, what is the op amp's (a) output voltage; (b) approximate output current?
Both op amps of Fig. P2-6 are in 14-pin dual-in-line packages. (a) Number the terminals. (b) Calculate $E_d$. (c) Find $V_o$.
$E_i$ is applied to the (-) input and ground to the (+) input of a 741 in Fig. P2-7. Sketch accurately (a) $V_o$ vs. $t$ and (b) $V_o$ vs. $E_i$.
Swap the input connections to $E_i$ and ground in Fig. P2-7. Sketch (a) $V_o$ vs. $t$ and (b) $V_o$ vs. $E_i$.
Refer to Problems 2-7 and 2-8. Which circuit is the noninverting zero-crossing detector, and which is the inverting zero-crossing detector?
To which input would you connect a reference voltage to make an inverting level detector?
You need a 741 noninverting voltage-level detector. (a) Will the output be at $+V_{\text {sat }}$ or $-V_{\text {sat }}$ when the signal voltage is above the reference voltage? (b) To which input do you connect the signal?
Design a reference voltage that can be varied from 0 to $-5 \mathrm{~V}$. Assume that the negative supply voltage is $-15 \mathrm{~V}$.
Design a 0 to $+50 \mathrm{mV}$ adjustable reference voltage. Derive it from the $+15-\mathrm{V}$ supply.
The frequency of carrier wave $E_c$ is constant at $50 \mathrm{~Hz}$ in Fig. P2-14. If $V_{\text {temp }}=5 \mathrm{~V}$, (a) calculate high time $T_H$; (b) plot $V_{\mathrm{o}}$ vs. time.
Assume that $V_{\text {temp }}$ is varied from $0 \mathrm{~V}$ to $+10 \mathrm{~V}$ in Problem 2-14. Plot $T_H$ vs. $V_{\text {temp. }}$.
In Fig. P2-16, $E_{\text {in }}$ is a triangle wave. The amplitude is $-5 \mathrm{~V}$ to $+5 \mathrm{~V}$ and the frequency is $100 \mathrm{~Hz}$. Sketch accurately the graphs of (a) $V_o$ vs. $E_{\text {in }}$; (b) $V_o$ vs. $t$.
Draw the schematic of a circuit whose output voltage will go positive to $+V_{\text {sat }}$, when the input signal crosses $+5 \mathrm{~V}$ in the positive direction.
Is the solution of Problem 2-17 classified as an inverting or noninverting comparator?
Draw a circuit whose output goes to $+V_{\text {sat }}$ when the input signal is below $-4 \mathrm{~V}$. The output should be at $-V_{\text {sat }}$ when the input is above $-4 \mathrm{~V}$.
Does the solution circuit for Problem 2-19 represent an (a) inverting or noninverting, (b) positive- or negative-voltage-level detector?