DS160PR1601: DS160PR1601 EQ gain

Chris Zhao1

Part Number: DS160PR1601

Hi experts,

For redriver DS160PR1601, I copied the EQ gain figure below.

what's the real DC gain or low frequency gain? Can I believe there is boost for low frequency? which means this part will boost signals in all bandwidth.

I copied a typical PCIe ctle curve below, it will attenuate low frequecy much more than the Nyquist frequency, so the eye after CTLE, the eye will look better, but the signal amplitude should be lower.

Regards

Chris

www.ti.com/.../DS160PR1601

9 months ago

0 Chris Zhao1 9 months ago

Expert 1240 points

If the channel before DS160PR1601 is very lossy, then the input amplitude should be relatively small, I guess I must use flat gain, is that right?

My initial phase will only use GEN1.

+1 David Waier 9 months ago in reply to Chris Zhao1

TI__Genius 17411 points

Hi Chris,

The EQ boost diagram you've shown on the left for the DS160PR1601 illustrates the CTLE boost of the device at various frequencies - note at PCIe Gen1 (1.25GHz), there is relatively low boost from this device (~4dB max at EQ 19).

Please note other TI PCIe signal conditioning solutions listed here for your reference, which may provide higher boost at the desired PCIe data rate: https://e2e.ti.com/support/interface-group/interface/f/interface-forum/1045738/faq-which-redriver-retimer-should-i-use-for-each-pcie-data-rate?tisearch=e2e-sitesearch&keymatch=pcie%2520device%2520overview#

Best,
David

0 Chris Zhao1 9 months ago in reply to David Waier

Expert 1240 points

Hi David,

Thanks for your quick response, so the boost value is positive.

For ~4dB at EQ19, about 1.5 times; so for an 1.25GHz sine wave, if the input amplitude is 200mV, the output will be 300mV. is that right?

Regards

Chris

+1 David Waier 9 months ago in reply to Chris Zhao1

TI__Genius 17411 points

Hi Chris,

The CTLE boost is positive, yes.

Your understanding of the amplitude boost is correct, this would be ~315mV if input amplitude were 200mV @ 1.25GHz.

Best,
David

0 Chris Zhao1 9 months ago in reply to David Waier

Expert 1240 points

I see, so it's active CTLE.

Have a nice day!

Regards

Chris

0 David Waier 9 months ago in reply to Chris Zhao1

TI__Genius 17411 points

Yes that is correct.

Have a nice day as well Chris.

-David

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DS160PR1601: DS160PR1601 EQ gain