• Resolved

PCM1792: no sound

Prodigy 210 points

Replies: 3

Views: 20

Part Number: PCM1792

Hello,

I'm designing an audio hifi power amplifier with integrated DAC, a PCM1792.

I build first prototype and I can't made the PCM1792DB (I purchase PCM1792DB) working.

The I2S come from an XMOS MCU, data format is I2S 24bit.

Then, I look on SCK pin, 24.576Mhz is present, on BCK I have the right frequency (around 2.8Mhz for a 48khz datarate), on LRCK I found the 48Khz frequency and I see bitstream on DATA pin.

nRST is high level, but maybe the init sequence is wrong.

init sequence:

1- 3.3VDAC is up, SCK is feed with a clock (24.576Mhz) analog power is OFF (5VA feeding analog pins of PCM1792), nRST is low

2-5VA analog is ON when I press a button (before I press buton 5VA is OFF)

3-XMOS MCU start init sequence with nRST only (I2C pins stays high level, no communication)

I expected PCM1792 start with right config (default I2S 24b format) and then seeing some sound from PCM1792 but nothing, 0VDC even the I bias which should give me about 2.5VDC on the 390R resistor is not working.

I see a voltage around 2.45V on IREF pin connected to a 10KR resistor.

Attached my schematics and a screen shoot showing nRST pin (nRST pin stay low when device power up, then XMOS MCU apply reset and put nRST in high level)

Tripple check solders, change PCM1792 with a new one; nothing change.

Any ideas ?

brix.pdf