SNC521

One Channel Direct Drive Speech Controller

Ver: 1.3

August 26, 2003

5

Input data

Typical value of output current (mA)

0

0

1

3/127

…

N

n*(3/127)

…

127

3

DAC output

PWM: A PWM (pulse width modulation) circuit is built-in SNC521. PWM can

convert input digital data into pulse trains with suitable different pulse width. The

maximum resolution of PWM is 7 bits. Two huge output stage circuits are

designed in SNC521. With this advanced circuit, the chip is capable of driving

speaker directly without external transistors.

The recommended application

circuit is illustrated as follows.

PWM Output

VCC

BUO1/VO

1K

BUO1/VO

BUO2