SNC558

Two Channel Direct Drive Speech Controller

Input data

Typical value of output current (mA)

0

0

1

3/127

…

N

n*(3/127)

…

127

3

VCC

BUO1/VO

1K

DAC output

PWM: A PWM (pulse width modulation) circuit is built-in SNC558. 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 SNC558. With this advanced circuit, the chip is capable of driving

speaker directly without external transistors.

The recommended application

circuit is illustrated as follows.

BUO1/VO

BUO2

PWM Output

Ver: 1.2

November 26, 2002

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