Dear team,
I have three questions about using ADS4222EVM, could you please help on those questions? Thank you.
1. I used ADS4222EVM+ TWS1405EVM and used HSDC pro to capture input signal.
When I feed:
Input Amp:-50dBm; Freq:1MHz at J6
Clock source: 61.44MHz at J19
I can get good FFT, but the code has some peak as the following picture. May I know the reason?
2. When I feed:
Input Amp:-40dBm; Freq:1MHz at J6
Clock source: 61.44MHz at J19
The FFT is really bad, and it seem input signal is saturated. But I saw the input spec of ADS4222 at datasheet can feed 2Vpp input signal. Why does ADC input saturate at only -40dBm?
3. How to revise the EVM if I would like to input 1kHz?
Because 1kHz input will be filter out by WBC1-1.
I think I could revise the following settings at EVM to feed 1kHz. Please let me if this is correct or any missing.
- Short T1 pin1 to pin6 and pin4 to pin3.
- DNI R119 and R123.
- Put 0hms at R120 and R129.
- Put 50ohms at R19 and R42
Regards,
Polly Chung