Now I am using ADS5400 to capture the input signal.
The characteristics of the input signal is as follow:
1) single-ended input, 50ohm;
2) signal bandwith :500MHz;
3) input voltage: -2V to +0.5V;
4) DC-coupled;
And the input characteristics of ADS5400 is as follow:
1) Differential input, common mode voltage of 2.5V;
2) The input voltage at each pin of the differential input must be in range of 2.0V to 3.0V;
I ask a question at High Speed Data Converters Forum, and Richard P. advise me to use LMH5401 to achieve it and advise me to open a question at High Speed Amplifiers Forum.
I find the input circuitry of TSW12J54EVM is similar to my requirement.
In datasheet, the gain of LMH5401 should above 2, so the output of LMH5401 is out of ADS400’s range.
I use an attenuator to attenuate the input signal of LMH5401.
Question 1:Can this circuitry work ok for my requirement?
Question 2:The gain of the LMH5401 shoule be set to ?and the optimal resistance value is ?
Question 3:Now the lowpass filter is 2GHz, if I need 800MHz, how to change it ?
Thanks!
Best wishes!