PCM2903C: Speaker & microphone in a Dashcam product over USB interface

Shubham Srivastava

Part Number: PCM2903C
Other Parts Discussed in Thread: PCM2912, , PCM2912A

Hi,

I'm planning to use this IC for extension of audio interface over USB in a Dashcam product. The use case for us is to have speaker & microphone.

So can we connect microphone to pins Vin L (12) & Vin R (13) ?

This will clarify the doubt for PCM290xx series use case.

Regards,

Shubham

over 4 years ago

0 pdjuandi over 4 years ago

TI__Mastermind 29775 points

Hi,

PCM2912 has MIC input https://www.ti.com/product/PCM2912A maybe it is more suitable for your case.

Regards,

Peter

0 Shubham Srivastava over 4 years ago in reply to pdjuandi

Prodigy 50 points

Hi Peter,

I referred to PCM2912 already but it supports single mic, in our use case we need 2 mics. That's the reason I'm looking for ICs with at least 2 analog IN channels.

Can you please help me with clarification for mic connection to PCM2903C?

Regards,

Shubham

0 pdjuandi over 4 years ago in reply to Shubham Srivastava

TI__Mastermind 29775 points

Hi,

OK, in that case use PCM2903C.

Please refer to this document for more information.

https://www.ti.com/lit/an/sbfa020/sbfa020.pdf?ts=1639597906606&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FPCM2903C

Regards,

Peter

0 Shubham Srivastava over 4 years ago in reply to pdjuandi

Prodigy 50 points

Thanks for the confirmation Peter.

Also I see we need to add external biasing & filter circuit in case of PCM2903C which will increase the BOM cost. So for comparison we will consider PCM2912 also. Just needed one clarification on this part, can we configure any of the pins like Mute, Rec & Play for some other use case like an interrupt?

Regards,

Shubham

0 pdjuandi over 4 years ago in reply to Shubham Srivastava

TI__Mastermind 29775 points

Hi Shubham,

Unfortunately no. These pins (Rec and Play) are fixed use for status indicator and MUTE is an input pin.

Regards,

Peter

0 Shubham Srivastava over 4 years ago in reply to pdjuandi

Prodigy 50 points

Hi Peter,

We need the interrupt as input pin only. Is it possible to change the functionality of mute pin to something else, like adding a user button & intimating the host processor when it is pressed and let the processor make decision on what to be done?

Also it would be great if you can suggest some other ICs which can support more than 2 mics.

Regards,

Shubham

0 pdjuandi over 4 years ago in reply to Shubham Srivastava

TI__Mastermind 29775 points

Hi,

No, there's no register to reconfigure this and it's also tied to the USB audio class mute functionality.

This link shows the USB converter devices and besides PCM2912A the rest can take 2 but it's similar to PCM2903C above.

https://www.ti.com/audio-ic/converters/usb/products.html

Regards,

Peter

0 Shubham Srivastava over 4 years ago in reply to pdjuandi

Prodigy 50 points

Hi Peter,

Thanks for the clarification. Also can I assume the same is applied for PCM2903C as well, where the HID pins can not be configured for some other use cases? Please confirm.

Regards,

Shubham

0 pdjuandi over 4 years ago in reply to Shubham Srivastava

TI__Mastermind 29775 points

Yes.

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PCM2903C: Speaker & microphone in a Dashcam product over USB interface