AnsweredAssumed Answered

Pop noise when using AD1937 codec

Question asked by ETT Employee on Oct 7, 2014
Latest reply on Nov 5, 2014 by larsc

I’m working on audio with AD1937

OS is Android-J.

Recently, we found that there is pop noise when using tinyplayer

 

 

1.      when to ramp up AD1937 to play music

2.      when to ramp down AD1937 after playing

 

It can be reproduced with tinyplay
with no change of any gain in codec beforehand

tinyplay xxx.wav –D 0 –d 4

 

Tested audio clip is 16bit,
48KHz, stereo

 

Here are register dump in codec
captured before and while playing audio

 

[Before playback]

00: 1d

01: 03

02: 41

03: 04

04: 03

05: 00

06: 00

07: 00

08: 00

09: 00

0a: 00

0b: 00

0c: 00

0d: 00

0e: 03

0f: 40

10: 68

 

[While playback]

00: 9c

01: 0b

02: 40

 

04: 02

05: 00

06: 00

07: 00

08: 00

09: 00

0a: 00

0b: 00

0c: 00

0d: 00

0e: 02

0f: 40

10: 68

 

And I did tested with DAC1 volume
0 and DAC1 switch off, but could still hear pop sound.

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