0195136047.pdf

260 ANALOG BUILDING BLOCKS AND OPERATIONAL AMPLIFIERS

expression forGPfor the case whenRi 1 =Ri 2 =
Ri, andRo 1 =Ro 2 =Ro.
5.1.11Consider Example 5.1.4. For what value ofVoutis
the power dissipation maximum?
5.1.12In the circuit of Example 5.1.4 letvin= 1 − 0 .5 cos
ωt. Determine the time-averaged power dissipated
in the amplifier.
*5.1.13In the circuit of Example 5.1.4, what is the smallest
value ofRLso that no matter what valuevouttakes
in the range of 0 to 20 V, the power dissipation in
the amplifier never exceeds 50 mW?
5.1.14(a) An audio amplifier withRi=10 k, Ro=0,
andA ̄(ω), as shown in Figure 5.1.13(a), is
used in the circuit shown in Figure P5.1.14
withRS = 1 k, RL = 16 , andC =
0. 2 μF. SketchGV(f) versus frequency if
GV(f) is defined byGV(f)=

∣

∣V ̄L

∣

∣/

∣

∣V ̄S

∣

∣.

(b) Findfmaxfor this circuit iffmax, the maximum

usable frequency, is defined as the frequency

at whichGVhas dropped 6 dB below its max-

imum value.

5.2.1Using the ideal op-amp technique, find the closed-

loop voltage amplificationA′for the circuit shown

in Figure P5.2.1.

5.2.2Findvoin the circuit shown in Figure P5.2.2 by

using the ideal op-amp technique.

5.2.3In the circuit shown in Figure P5.2.3, use the ideal

op-amp technique to find:

(a)voas a function ofvi.

(b) The voltage atA.

*5.2.4Determine the open-circuit output voltagevoof the

system shown in Figure P5.2.4 as a function of the

input voltagevi.

5.2.5Find the gainvo/vifor the circuit shown in Figure

P5.2.5 and comment on the effects ofR 3 andR 4 on

the gain.

+

+

− −

−− C V−−−in RL V−L

RS

VS

Figure P5.1.14

−

vi + vo

R 1

R 2

R 3

Figure P5.2.1

−

+

vo

RF

I

Figure P5.2.2

−

vi + A vo

2 V

− +

Figure P5.2.3