There are many considerations when driving an ADC. A primary consideration is
the noise and linearity of the amplifier driving the ADC. The effective
resolution of an ADC is affected by its total harmonic distortion and noise
(called “SINAD” in ADCs and “THD+N” in amplifiers). The driving amplifier must
have a THD+N that is better than that of the ADC in order to maintain the
resolution of the ADC. The ADA4500 has a THD+N of 0.0004% or 108 dB. This makes
the ADA4500 suitable for processing signals into precision ADCs like the 16-bit
AD7980 with its excellent SINAD of 91.5 dB.