TLV320AIC3253EVM-K: Frequency for a digital PDM microphone

Jagrit Arora

Hello,

I am trying to evaluate a digital PDM microphone using TLV320AIC3253EVM-K. I have attached the microphone to J6 of the evaluation kit. I have removed jumper W15. All the other jumpers and switches are correct.
The microphone operates at 3.12MHz input clock frequency, but the evaluation module (EVM) is operating at default 44kHz.
Is the 3MHz input clock frequency for microphone automatically generated by the EVM or do I need to define it myself somewhere ? If I need to define it myself, could you please tell me where can I define it.
Also is the microphone output automatically decimated down to 44kHz ? Or do I need to change the default frequency of EVM to 3MHz and perform the decimation and low pass filtering myself?

Thanks and Best Regards,
Jagrit Arora

over 5 years ago

0 Diego Melendez over 5 years ago

TI__Guru 57800 points

Hi, Jagrit,

The microphone clock is provided by the codec, assuming the internal clock tree is properly set. You can look at the reference digital mic code as example.

The codec will take the data from the mic and internally will down sample it to the system sampling rate.

Best Regards,

-Diego Meléndez López
Audio Applications Engineer

0 Jagrit Arora over 5 years ago in reply to Diego Melendez

Prodigy 190 points

Hi Diego,

Thanks a lot for your kind help.

Best Regards,
Jagrit Arora

Audio

Audio forum

TLV320AIC3253EVM-K: Frequency for a digital PDM microphone