Audio Engineering

292 Chapter 9

(a)

Vcc

Output

Vref

R 2

Q 1 Q 2

R 1

0V 0V

Input

Figure 9.8 : Long-tailed pair layouts.

(b)

Vref 2

Vref 1

Output

Vcc

R 1

R 2

Q 3

Input Q 1 Q 2

V0V

Q 1

Output

0V 0V

Vcc

Input

R 1

Figure 9.9 : Emitter–follower.