Hi,
We are using LM49350 audio codec in our application. We are facing an issue where the mic output is getting interfered with Headphone output.
We are running below experiments in our set up using arecord & aplay in our application.
1. Record silence - using arecord - The noise floor at the mic output is close to -70dB, which is on the expected lines.
2. Record silence (using arecord) and play silence (using aplay) simultaneously - The noise floor at mic output is increased to -40dB. This is where we are seeing interference from Headphone output at the Mic output. We have disabled ALC on both ADC and DAC side to observe the noise floor.
We are using Mono input and stereo output in our application. Below are the register settings we are using in our initial setup. I would appreciate if some one can take a look at the register settings and let us know if we you see any issue.
Register -- Value
--------------------
0x0 -- 0x7
0x1 -- 0x0
0x2 -- 0xd
0x3 -- 0x0
0x9 - 0x3
0xa - 0xc0
0xb - 0x0
0xc- 0xbf
0x51 - 0x5f
0x61 - 0x5f
0x80 - 0x0
0x81 - 0x0
0xa0 - 0x0
0x11 - 0x2
0x12 - 0x2
0x15 - 0x8
0x16 - 0xf
0x20 - 0x43
0x30 - 0x41
0x42 - 0x0
0x43 - 0x1
0x44 - 0x1
0x50 - 0x1a
0x52 - 0x0
0x53 - 0x2
0x54 - 0x1b
0x55 - 0x2
0x56 - 0x2
0x60 - 0x1c
0x62 - 0x0
0x63 - 0x2
0x64 - 0x1b
0x65 - 0x3
0x66 - 0x3
0x82 - 0xf
0x89 - 0x33
0x8a - 0x33
0x83 - 0xc
0x87 - 0x3f
0xa1 - 0xf
0xa8 - 0x33
0xa9 - 0x33
0xa2 - 0xc
0xa6 - 0x3f
0x70 - 0x1
0x71 - 0x0
Thank you in advance.
Regards,
Durga Prasad.
Hi Durga -
This question was sent to Gerardine Ly directly as well. She will respond to you offline.
Nisha
H Nisha,
I got in touch wit Gerardine Ly and she is helping us in solving this issue.
Best Regards,