SA1469XH

4)

When the voltage of the mute pin is above 2V, the mute circuit is stopped and the output circuit is operated

normally.

5)

If the chip temperature rises above 175

°C, then the TSD (Thermal Shutdown) circuit is activated and the

output circuit is muted.

2. TSD (THERMAL SHUTDOWN)

Output Driver

Bias

R2

R1

Qn

1)

TSD circuit.

2)

The base-emitter voltage of the TR, Qn is designed to turn-on at below voltage.

3)

When the chip temperature rises up to 175

°C, then the turn-on voltage of the Qn would drop down to 460mV.

(Hysteresis: 25

°) and, the Qn would turn on so the output circuit will be muted.

3. OP-AMP

OP-Amp is integrated in the IC for user convenuence.

OPIN(+)

OPIN(-)

OPOUT

Pins 14, 15 and 16 may be left open when the operational amplifier is not used.

4. DRIVER

1)

2)

The input signal through the pin # 3 is amplified by 13K/10K times and then fed to the level shift.

3)

The level shift produces the current due to the difference between the input signal and the arbitrary reference

signal. The current produced as +

ΔV and -ΔV is fed into the driver buffer.

4)

Driver buffer operates the power TR of the output stage according to the state of the input signal.

HANGZHOU SILAN MICROELECTRONICS CO.,LTD

REV:1.4

2008.07.23

Http://www.silan.com.cn

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