MP7770 –2 X 45W STEREO SE OR 90W MONO BTL CLASS D AUDIO AMPLIFIER

MP7770 Rev.1.0

www.MonolithicPower.com

14

12/4/2012

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Over-Temperature Shutdown

Thermal monitoring is also integrated into the

MP7770. If the die temperature rises above

150°C, all switches turn off. The temperature

must fall below 130°C before normal operation

resumes, with the same power-up sequence

used to prevent popping noise.

Over-Temperature Warning Output

The MP7770 includes an open drain, active low

fault indicator output to act as an over-

temperature warning (OTW). The OTW pin is

asserted when the die temperature reaches

125°C and goes low until the temperature drops

below 115°C.

Do not apply more than 6V to the OTW pin.

Fault Output

The MP7770 includes an open drain, active low

fault indicator output on the FAULTB pin. A fault

triggers if either the current limit or thermal

shutdown is tripped.

A fault on any channel will cause the FAULTB

pin to pull low. A fault on either channel will

cause the all outputs to go into high impedance.

When the fault goes away, the MP7770 will

resume normal operation.

Do not apply more than 6V to the FAULTB pin.

Normal Operation

Overcurrent

detected?

No

Disable output,

Fault =L

Yes

Meet restart

condition (start

Enable output ,

Fault=H

Yes

Yes

No

TEMP>125 °C

？

No

OTW =L

Yes

TEMP<115 °C

？

OTW=H

Yes

No

TEMP>150 °C

？

No

Disable output ,

Fault =L

Yes

TEMP<130 °C

？

Yes

No

Meet restart

condition (start

Yes

No

Enable output ,

Fault =H

Around 1ms

time out

finished?

No

Figure 2: Fault Timing Chart