SN75DP126: SN75DP126

Hi Ian,

1uF is too large, the recommended starting point is 200nF.
Do you have scope captures of EN, Vcc, and Vdd?

Regards

Dear Guys,
What’s the good waveform for EN? I cannot find it in your datasheet.
Thanks, Ian.

Hi Ian,

This device mentions a reset has to be asserted after the power supply is stable, but there are no specific timing parameters.
Although, it has voltage parameters:
VTH(EN) -> EN input threshold voltage min=280mV max800mV
EN Vil(max) = 0.285V Vih(min)=0.8V

POR capacitor doesn't delay the signal, they make a long slope.
My guess is the very long slope from 1uF capacitor sets the device in an unknown state.

Regards

Dear Guys,

Would you pls check schematic as below if need to modify? Customer using DP126 but no working.

C94, C95: Can it REMOVE ?

C39, C40, R66, R67: It's need by COM Express design guide .

C389, C390: Can it REMOVE ?

C394, C395, R307, R308: Keep ?

Thanks, Ian.

Hi Ian,

Could you elaborate on the issue the customer is facing, is there any video on DP or HDMI?

I got a little confused with all the images, could you share the customer's schematic for review?

I will send you by email the DP126EVM schematic and the diagram of typical AUX channel connection.

Regards