CDCM61001 : about capacitor values of /RSTN pin

Thank you for your responce.

Phenomenon that the clock amplitude become large output after power has occured.

Could you advise how not to output the clock of large amplitude?

Please refer the attached files A1.png.
- Large amplitude period is 45.2ms
- The period during from CE VIH to RSTN VIL is 3.4ms

Thanks in advance for your support.

I don't think I understand your question. If I look at the scope shots, the outputs are operating fine but takes 45ms after the RSTN pin has reached Vih. Are you asking to reduce the delay of 45ms?

No. Customer want not to output large amplitude at power on.
They set output is 1.2Vp-p but output is large amplitude 2.7Vp-p at power on.
Could you advice how not to output large amplitude?

Thanks in advance for your support.

Can you show the customer schematic on the output section? Also please provide the pin config that customer is setting on the device? If proprietary, you can send to me by email at madhu_b@ti.com. Thanks.

Dear Madhu Balasubramanian

Please refer the attached file.

Thanks in advance for your support.

5751.schematic.pdf

Are you using a high impedance probe or low impedance to the 50 ohm in the scope? I see that the 100 ohm between P and N is no connect and in order to fully avoid reflections, you need to keep the 100 ohms and use a differential probe.

You are measuring a high frequency clock and given the time scale, there seems to be reflections appearing as overshoots and the scope is likely rebuilding the signal using these and showing as a very high amplitude signal.

If you zoom into the time scale in order to look at 1 or 2 clock periods of 156.25MHz, you should get a clear picture of what's going on.

I send you the attached file of zoomed into the time scale.
Could you advice anything about scope shots?

Thanks in advance for your support.

How are you measuring? Using high impedance probe? What is the current draw? Can you also check the common mode level of the output pins?

I want to check to our customer. Pls wait for a moment.

Yes,our customer has been measured using a differential probe as your recommended.

They guess the measurement method is not the cause this phenomenon will return to nomal amplitude tens msec after the start.

Are there any factors that are considered in the measurement method other than?

Thanks in advance for your support.

Sorry I am not following. Are you saying that the outputs come back to normal levels after some time?

If customer using differential high impedance probe, please make sure that they are terminating the outputs with a 100 ohm between P and N.