This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

SN75LVDS82: SN75LVDS82 few Data bus output not working

Part Number: SN75LVDS82

Hello,

I am using SN75LVDS82 and SN74LVDS83 as LCD and Keypad interface in my system. Recently i got a new proto boards build with these parts.

SN74LVDS83 is working good as expected, i can see the data displayed on LCD.

But SN75LVDS82 is not working as expected. Here, key pad serial data is connected to channel 4 (A3M & A3P) and output taken from output data line D11, D16, D17, D23 & D27.

When i press the key pad, i can't see the any response at D11 and D17 but other data lines are getting correct response. Actually i have compared the old board result with new board, old boards are working good and getting response on all the data lines when i press the key. When i say old and new board there is no difference on LVDS design, everything same. Layout revised for some other purposes.

i am wondering why few data lines are respond and others not?

Is anyone faced similar issues? Any recommendation to debug this issue?

  • Hello Vinoth,

     Internally in the device it is not possible to not output part of the bits and outputs the rest.

     They must be some changes on your PCB layout/populated components...etc which prevent these two lanes from outputting the signal.

     You may use a second set of boards for your testing, Also you may double check the other components on your board.