I'm using the ADA4937 as a buffer/driver for the AD9649BCPZ-40 ADC.
My system is required to have 1k input impedance. The current line-up is: input -> anti-alias LPF -> ADA4937 -> differential RLC LPF -> AD9649BCPZ-40.
Would it be better to design the ADA4937 with 50 ohm input impedance and design the anti-alias LPF to transform from 1k to 50 ohm, or should I just design everything at 1k? Required bandwidth is less than 10 MHz but I need it to be low noise.