AnsweredAssumed Answered

ADL5202 abnormal peak at output

Question asked by katsu on Mar 25, 2016
Latest reply on Apr 7, 2016 by katsu

Hello,

 

Issue:
When changing the amplitude
of input signal to certain value from zero, abnormal peak of a few period is observed at the beginning of output amplitude changing to certain value from zero.

Condition:

Gain is set by Parallel I/F transparent mode.

Gain is fixed to max.

Input signal is 128MHz sine wave.

Output level is 0dBm in 150 ohm.

Measured by FET probe contacting at 150 ohm termination (>>See the attachment please).

Application circuit:

Similar to Figure 55. Wideband ADC Interfacing Example Featuring One-Half of the ADL5202 and the AD9268 which is described in datasheet.

Request:

1. Could you please tell me the ways to solve this issue?

2. Could you please provide the transmission function of the internal ac-coupled feedback path? The feedback path is described in p.18 of datasheet. Would like to examine if excess compensation causes this issue.

 

Best Regards,

Outcomes