Features

Benefits

1.

Description

The integrated circuit U4083B is a low-power audio amplifier for telephone loudspeak-

ers. It has differential speaker outputs to maximize the output swing at low supply

voltages. There is no need for coupler capacitors. The U4083B has an open-loop gain

of 80 dB where the closed-loop gain is adjusted with two external resistors. A chip dis-

able pin permits powering down and/or muting the input signal.

Figure 1-1.

Block Diagram

Bias circuit

U4083B

4k

4k

50k

50k

125k

4

3

2

7

1

8

5

6

Amp1

Amp2

FC2

FC3

Vi

VS

VO1

VO2

CD

GND

Low-power

Audio Amplifier

for Telephone

Applications

U4083B

Rev. 4655C–CORD–03/06