DS90UH948-Q1: SSC function for LVDS

Hi Fanbin,

Fanbin Meng said:

They want to know for 941-948 configuration, if the SOC support the spread spectrum, would the 948 LVDS has some improvement?

If the EMI source is x948, then spread spectrum on the x941 input will not improve x948 EMI performance. The DSI input is retimed and converted into FPD-Link which is then retimed and converted into OLDI LVDS. The retiming prevents the SSC from the previous link to affect the next output. 

Please provide the following information for better support:

• Can you share the EMI data where x948 is failing? 
  • Is the failure frequency at a multiple of the PCLK Nyquist frequency?
• Have you tried operating at a different PCLK rate and see if EMI failure is PCLK dependent?
• Please share schematic and layout (Altium files preferred, pdf accepted as alternative)

I have attached our detailed guide on layout for EMI/EMC performance which will walk you through all our recommendations. Feel free to share with customer.

FPD-Link_EMI_EMC Optimization (1).pptx

Thanks,

Ragav Subramanian