D **12.40 Consider the compound-transistor class AB output stage shown in Fig. 12.19 in which Q2 and Q4 are matched transistors with VBE = 0.7 V at 10 mA and β = 100, Q1 and Q5 have VBE = 0.7 V at 1-mA currents and β = 100, and Q3 has VEB = 0.7 V at a 1-mA current and β = 10. Design the circuit for a quiescent current of 1 mA in Q2 and Q4, IBIAS that is 100 times the standby base current in Q1, and a current in Q5 that is nine times that in the associated resistors. Find the values of the input voltage required to produce outputs of ±10 V for a 1- kΩ load. Use VCC of 15 V.