DP83620: Output Voltage (-Vout)

Hi Kenshow,

There is no register control for adjusting the VOD.

However, this device is designed for margin. I am surprised it is not passing.

Can you please send me the schematic? Also, please let me know how you are taking the measurement.

Are you using a cable? what length? Are you using a 100 ohm termination board?

Hi Ross,

I cannot post the circuit and layout information here. So, I am contacting TI's local FAE.

Thank you.

Regards,
Kenshow

Hi Ross,

May I change an external bias resistor value to adjust VOD?
To change the resistor value, the waveform could be moved to the middle of the test condition. And, this seems to have been solved the problem.

Best Regards,
Kenshow

Hi Ross,

 I am waiting for your reply about changing value of  an external bias resistor.

 Please comment on my solution.

Thanks,
Kenshow

Hi experts,

Do you have any comments?

Thanks,
Kenshow

Hi Kenshow,

If you adjust the bias resistor as you mentioned, you can change the driver swing.

The bias resistor sets the current mirror for the current-mode line driver. If you increase the resistance you should see the swing reduce as the current will decrease. Opposite for when you decrease the resistance. 

How far are you having to change the resistor to get it to pass?