(a) For the circuit of Problem 5.15, calculate the maximum possible average output power than can be delivered to a load R_Lif the instantaneous power dissipation per device must be less than 100 mW. Also specify the corresponding value of R_Land the circuit efficiency (for the output devices only). Assume sinusoidal signals.

(b) Repeat (a) if the maximum instantaneous power dissipation per device is 200 mW.

Data from Prob. 5.15:

For the output stage of Fig. 5.20a, assume that V_CC = 15 V, β_F (pnp) = 50, β_F (npn) = 200, and for all devices V_BE(on) = 0.7 V, V_CE(sat) = 0.2 V, I_S = 10^ˆ’14 A. Assume that the magnitude of the collector current in Q_13A is 0.2 mA.

Fig. 5.20 a:

Transcribed Image Text:

+V cc |0.17 mA Q138 Q134 BIAS 0.22 mA Q14 Q19 0.68 mA| Q18 7, V2 Q20 V1 Q23 Q17 +o -V cc (a)