AnsweredAssumed Answered

Best way to filter AD9257 (A/D) input with ADA4932 driver?

Question asked by Lionelwallace Employee on Sep 10, 2014
Latest reply on Sep 18, 2014 by UmeshJ

I received this customer question:

 

We are using ADA4932-1 to drive the inputs of a AD9257 ADC.  See attached schematic

 

We only need about 3MHz BW out of the driver.  I was thinking of simply increasing the input caps (C13, C15 and C20) to 220pF to reduce BW.

 

I looked at the ADA4932 and AD9257 data sheets and could not deduce what practical limit should be placed on the max value for these caps.

 

Any thoughts?  Would it be better to put some feedback capacitance across the 499 ohm feedback resistors (R9 and R16) of the ADA4932?   Or should I increase input caps AND add feedback caps?  Any issues I should be aware of?



Attachments

Outcomes