What is the relationship between value of Input Level Control register (Address
0) and gain value? Why 1.8836 is corresponding to the gain of 11dB?
A gain of G=1.8836 corresponds to 5.5dB and in the AD1970, this value is
multiplied by 2 to get a level of 11dB. Thus, a gain of 1.99 – the maximum
allowed by the binary format here – would yield a gain of ~12dB (11.95dB).