About HDMI_CEC level shifting on NX development board

Robotics & Edge Computing Jetson & Embedded Systems Jetson Xavier NX
1

Hi,

On NX module, HDMI_CEC is a open drain bidirectional port in 1.8V power domain. On the development board, in the CEC level shifting & blocking section, there is a 162k resistor labeled R62 pulled up to 3.3V. So I think the value of R62 should be bigger enough. But, why 162K? Or only because it’s just on the shelf?

Thanks.

3

It is under checking, will update once available, thanks.

4

HDMI spec requires 27kohm pull up on CEC, so we have a 162k and a 32.4k pull up on either side of the FET, to create 27k in parallel.

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