Kindly find the attachment ,
I plan to use the AD797 and discrete scheme in the in front of AD9257 where 1.8K and 1.5K used to attenuate the input signal as well as common mode voltage add for ADC input.
1.8K and 1.5K provides near to -7dB attenuation for input signal.
i am worry about internal resistance of ADC ,whether the internal resistance affect my attenuation resistors values (1.5K|| Rin of ADC).
Is it change the attenuation level ??
My input frequency is 500Khz only, So the AD797 is suitable for that.
Kindly suggest the solution.