Regarding the issue of the ADAU1787's power-on startup, the normal power supply (DVDD) does not output any voltage.

Hello!

I made a circuit board that consists of 3 ADAU1787 chips and one MCU.However, I have encountered some problems recently. I have attached my AD project files and a screenshot of the ADAU1787 hardware configuration circuit.DSP_LowPower_V1(0423).zip

The REG_EN of the three ADAU1787 chips on the board are all connected to AVDD for enabling.

Both AVDD and HPVDD are powered by the same VA1.8V.The distinction between VA and VDD on the board is a 0-ohm resistor, and IOVDD is connected to VDD.

The peripheral circuits of the three ADAU1787 chips are the same, but after powering up the board and getting it connected, I encountered some strange issues. On the same board, the DVDD voltage of ADAU1787 is 0.9V, indicating that the DSP has successfully started and is functioning normally. However, for some DSPs, the DVDD output is 0.

Using U1, U2, and U3 to represent the three ADAU1787 chips,
The first main control board, U1 has no DVDD output, while U2 and U3 have outputs.
The second main control board, U1, U2, and U3 all have no output, and the voltage measurement is around 90mV.
The third main control board, U2 has no output, while U1 and U3 have an output of 0.9V, but then U1 loses its output.

I would like to ask, why is this the case? I can't see any problem. Is there something wrong with my design? What should I do?

Audio Signal Processors

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ADAU1787

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