SoloX Source Series Resistor LVDS

scottgauche — Fri, 30 Sep 2016 14:03:27 GMT

Hi,

Does NXP have any recommendations for adding source series resistance to the LVDS output of the SoloX? We would like to slow down the edge rates. We are running the LVDS at 24.58 MHz.

We are trying to lower the amount of 688 MHz (LVDS parent clock) noise we are seeing in emissions scans. We were able to add 10 pF 0201 capacitors at each LVDS pair between the vias under the SoloX and see the emissions level go down. But we aren't able to test adding source series resistors because the traces are on internal layers until they reach the connector.

We use a deserializer (DS90CF384) to drive a RGB parallel LCD on another board with 100 ohm termination resistors for each LVDS pair.

This is our LVDS clock tree:

pll5 0 0 688239984 0
pll5_bypass 0 0 688239984 0
pll5_video 0 0 688239984 0
pll5_post_div 0 0 172059996 0
pll5_video_div 0 0 172059996 0
ldb_di0_sel 0 0 172059996 0
ldb_di0_div_7 0 0 24579999 0

Re: SoloX Source Series Resistor LVDS

igorpadykov — Sat, 01 Oct 2016 00:15:50 GMT

Hi SCOTT

one can look at LVDS common-mode chokes (represent also resistance)

p.13 SPF-27962 i.MX6SX SabreSD schematic

Schematics (1)
IMX6SOLOX-SABRESDB-DESIGNFILES
http://www.nxp.com/products/software-and-tools/hardware-development-tools/sabre-development-system/sabre-board-for-smart-devices-based-on-the-i.mx-6solox-applications-processors:RD-IMX6SX-SABRE?fpsp=1&tab=Design_Tools_Tab

Best regards
igor
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topic Re: SoloX Source Series Resistor LVDS in i.MX Processors

SoloX Source Series Resistor LVDS

Re: SoloX Source Series Resistor LVDS