TDA4VL-Q1: How to set the Spread Spectrum function

bing zhu

Part Number: TDA4VL-Q1

Hi, experts ,

We found that the 1600MHZ frequency point exceeded the standard during the EMI test, and we would like to try to see if we can pass the EMI test by spreading the frequency.

I've looked at the TRM and there are a couple of parameters I'm not sure how to use, can you elaborate?

How should I set the parameters Type of spread, Modulation dvider and Spread Depth? Thanks

Best Regards,

Bing

over 1 year ago

0 kcastille over 1 year ago

TI__Guru 54352 points

Bing,

Can you clarify which clock you are trying to experiment with?

Thanks,

Kyle

0 bing zhu over 1 year ago in reply to kcastille

Intellectual 360 points

Kyle，

The DDR clock is set to 1600MHZ, so it is suspected that the problem is introduced by the DDR, and the PLL used is PLL12.

Best Regards,

Bing

0 bing zhu over 1 year ago in reply to bing zhu

Intellectual 360 points

Kyle，

Why can't I write the 0x68c040 register value?

Best Regards,

Bing

0 Kevin S over 1 year ago in reply to bing zhu

TI__Mastermind 38170 points

You cannot use spread spectrum for DDR. If the 1600 MHz clock is causing issues, you will need to set your DDR frequency to a slower frequency that does not impact your EMI test.

Regards,
Kevin

0 bing zhu over 1 year ago in reply to Kevin S

Intellectual 360 points

Kyle，

Is there any other way than lowering the frequency of the DDR?

Best Regards,

Bing

+1 kcastille over 1 year ago in reply to bing zhu

TI__Guru 54352 points

Bing,

No the only option to move the 1600 MHz EMI signature is to move the clock to a slightly lower frequency.

Regards,

Kyle

Processors

Processors forum

TDA4VL-Q1: How to set the Spread Spectrum function