I am using the AD698 LVDT signal conditioner.
Datasheets say maximum input at A and B input channels is 3.5Vrms.
Is this value the differential voltage between the - and + input or is it the
voltage at 1 terminal in reference to ground?
The 3.5Vrms maximum refers to the voltage between the + and – terminals for
both the A and B inputs. Note the inputs are fully differential (-A is 180deg
out of phase with +A) and internally biased for the optimum input common mode