DS90UB948-Q1EVM: How to connect DS90UB948 and DS90UB927.

Apollo Chen79

Part Number: DS90UB948-Q1EVM
Other Parts Discussed in Thread: DS90UB927Q-Q1

Dear support team:

I have read the specification content. And DS90UB948Q-Q1 can be backward compatible to the DS90UB927Q-Q1 FPD-LINK III.

we're trying to connect a DS90UB927Q-Q1 board and a DS90UB948Q-Q1 board. But we meed into some problems.

It will blink irregularly when DS90UB948Q-Q1 output to LVDS or LCD panel. As you know that DS90UB927Q-Q1 supports data rate up to 720P , and DS90UB948Q-Q1 up to 1080P.

So Is there any timing issue between these two boards? May I ask how to solve this blink issue? Shall I need to set register or modify hardware to resolve this problem?

I recorded the problem into a video and uploaded it to google drive，link as below:

https://drive.google.com/file/d/1AtklpVhCBISaMxLT25Hi_FzrhprcLiPH/view?usp=drivesdk

Best regards,

Apollo

over 7 years ago

0 Steven(Shenzhen) Shi over 7 years ago

TI__Mastermind 30515 points

Apollo,
it doesn't matter for the 720p of UB927 and 1080P of UB948, they are fully compatible when working at 720p.
for you issue, please check the PCLK in your case, maybe the system is disturbed.

best regards,
Steven

0 Apollo Chen79 over 7 years ago in reply to Steven(Shenzhen) Shi

Prodigy 95 points

Hi Steven,

Does the register of VOD(0x4B) setting will cause the display blinking? Because bit [1:0] default value is 400 mV for 928, but 948 is 190 mV

DS90UB928

DS90UB948

0 Steven(Shenzhen) Shi over 7 years ago in reply to Apollo Chen79

TI__Mastermind 30515 points

Appolo,
it is dependent on the interconnection between UB948 output and the input of display controller chip. please check the sch. whether it has one more additional 100ohms between them? Few customers make a mistake that uses two 100ohms in the LVDS link, which makes the output swing smaller and would result into bit error and then blink.

best regards,
Steven

Interface

Interface forum

DS90UB948-Q1EVM: How to connect DS90UB948 and DS90UB927.