DS90UB940-Q1: MIPI CSI output clock abnormally

Kailyn Chen

Part Number: DS90UB940-Q1

Hello,

Our customer used DS90UB940 and worked normally ,but he found that if he disconnected the cable, it would still output MIPI clock signal, and the LOCK is still high level. So is it normal phenomenon? What is the output state when disconnected the cable ?

Best regards

Kailyn

over 5 years ago

0 Hamzeh Jaradat over 5 years ago

TI__Guru** 108400 points

Hello Kailyn,

If you disconnect the Cable between SER and DES, you will lose LOCK.

0 Kailyn Chen over 5 years ago in reply to Hamzeh Jaradat

TI__Genius 9560 points

Hi Hamzeh,

Thank you very much, but the question now is that it would still output clock even though disconnected the cable. Could you please help to analyze why does it appear this phenomenon?

Best regards

Kailyn

0 Hamzeh Jaradat over 5 years ago in reply to Kailyn Chen

TI__Guru** 108400 points

Hello Kailyn,

This is not expected behaviour. If there is no input signal (Cable disconnected) there should be NO Lock and NO CLK at the output.

Please measure the noise level at the input of your Deserializer, i.e. at RIN0+/- and RIN1+/- while the cable is not connected, and make sure these fullfil the

FPD-Link III Input specs listed in the datasheet page 11.

Interface

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DS90UB940-Q1: MIPI CSI output clock abnormally