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Class D Audio Amplifier IC Forum Discussions

jacksl528
Level 3
10 replies posted 5 questions asked 5 replies posted
Level 3

Hello, I did a project with ma12070p. The I2S signal and MCLK of ma12070p are from DSP audio board,
The problem now is to use 24V main power supply to supply power to the whole circuit board, convert 24V to 5V through DC-DC chip, and provide DVD and avdd (5V power supply) for DPS and ma12070p

But when I turned on the power, ma12070p couldn't work. I found the root cause of the fault, that is,Problems with start up procedure


I would like to ask how to provide 5V power supply for DPS before ma12070p startup when there is only one 24V power supply, so as to provide system clock (MCLK) in advance

 

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1 Solution
Meghana
Moderator
Moderator 50 solutions authored 5 likes given 100 replies posted
Moderator

Hello @jacksl528 ,

Thank you for posting on Infineon Community. 

As you have understood correctly, the clock signal has to be applied before enabling the device. Activation of MA12070P is controlled via pin "ENABLE".

In your case, you can add a pull up resistor from "ENABLE" pin to 5V/3.3V whichever is compatible with DSP I/O pins, which will keep the device disabled by default. Once the clock signal is generated, you can activate the device by applying a low pulse on "ENABLE" pin through DSP. 

Regards

Meghana R

 

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2 Replies
Meghana
Moderator
Moderator 50 solutions authored 5 likes given 100 replies posted
Moderator

Hello @jacksl528 ,

Thank you for posting on Infineon Community. 

As you have understood correctly, the clock signal has to be applied before enabling the device. Activation of MA12070P is controlled via pin "ENABLE".

In your case, you can add a pull up resistor from "ENABLE" pin to 5V/3.3V whichever is compatible with DSP I/O pins, which will keep the device disabled by default. Once the clock signal is generated, you can activate the device by applying a low pulse on "ENABLE" pin through DSP. 

Regards

Meghana R

 

Audio-guru-CPH
Employee
5 solutions authored 25 sign-ins 10 replies posted
Employee

Hello jacksl528 and Meghana.

For best stability, place the ceramic PVdd decoupling capacitors as close as possible to the PVdd pins of the device.

Also the fly-capacitors, should be placed as close to the device fly-cap nodes as possible.

In the picture of the PCB, they are placed at a relatively long distance. Keep traces as short as possible.

Thanks.

Best regards,

Rasmus Meyer.