PCM3002: codec reset and power up sequence

SHY

Prodigy 160 points

Part Number: PCM3002

Hi All,

Now i am prepare the PCM3002 for the Bluetooth eSCO function.

I want to know how can i reset the PCM3002 correctly(use /reset or sysclk ?)

thanks for your help.

over 5 years ago

0 Collin Wells over 5 years ago

TI__Guru 62935 points

Yes, you can use the active low reset pin, RST, to reset the product. Information about the RST pin as well as the device power-on reset timing can be found on pages 23 and 24 of the datasheet.

0 SHY over 5 years ago in reply to Collin Wells

Prodigy 160 points

Hi Collin,
thanks for your kind reply.
I want to know which sys_clk freq should be input for reset that at p.23/p.24.

256/384/512 * fs ?

Which clk input is necessary when reset ? fs and sysclk?

And how can i know if the reset is working ? check VDD with 2.4v?

0 Collin Wells over 5 years ago in reply to SHY

TI__Guru 62935 points

Hello,

Any of the 256/384/512*fs clock frequencies will work with the PCM3002 but as described in the "External Reset" section of the product datasheet you must input at least 1024 clocks at any of those frequencies in order to initiate the reset sequence. As described initialization starts on the rising edge of the RST, PDAD and PDDA signals and takes 1024 clocks for completion.

The device power will decrease significantly which can be monitored by measuring the power-supply current and the audio outputs will halt.

0 SHY over 5 years ago in reply to Collin Wells

Prodigy 160 points

Hi Collin ,
OK , i will try the reset function with Fsync and sysclk for 512*Fsync first.

And another question,which voltage should be out with Vref1/Vref2 after reset ?

I didn't get such information from that spec.

thank you.

0 Collin Wells over 5 years ago in reply to SHY

TI__Guru 62935 points

We agree this is a little unclear but we're pretty sure that the VREF1/2 and VCOM outputs are disabled during RESET/Power-down and will not be at the expected value during these conditions.

0 SHY over 5 years ago in reply to Collin Wells

Prodigy 160 points

Hi Collis,
thank for your reply again...

So when during reset /power-down , the VREF1/2,VCOM are disabled.
What about these 3 pins voltage after reset removal (i mean, in operation mode)?

0 SHY over 5 years ago in reply to SHY

Prodigy 160 points

hi Collis,
I want to know where can i get the Application Bulletin SBAA033 for lower sampling frequencies.(described in the p.2)

Because the sampling clock that i using is 8KHZ now.
thank you.

0 Collin Wells over 5 years ago in reply to SHY

TI__Guru 62935 points

Hello,

I've attached the SBAA033 document.

Low-Sample_Rate_Operation_sbaa033.pdf

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PCM3002: codec reset and power up sequence