Hi. I design AD7768 + AD4940 8 channels.
I have input signal of 5Vpp, from -2.5V to +2.5V, Vcm=0.
After ADA4940-1 ( Vs=+5V, Vs-=0) i have signal with Vocm=2.5V ( recieved from ADC Vcm pin and equal to AVSS1/2=2.5V)
Diffpair signal is from 1.25V min to 3.75V max with Vocm=2.5V.
I simulate this in LTSPICE
Help please, can i use reference of Vref=+2.5V (REF1+ = +2.5V, REF1- = 0) ?
For my signal Differential Input Voltage Range will be -2.5V to +2.5V ( max +3.75V - 1.25V = +2.5V and min 1.25V - 3.75V - = -2.5V).
I'am addraid that +3.75V on Ain+ or Ain- pin is more then Vref +2.5V and it will be not work.
But in datasheet
Absolute Analog Input Voltage Limits2 from AVSS =0 to AVDD1 =5V.
Correct, the Absolute Analog Input Voltage Limits is from AVSS to AVDD1 and the Differential Input Voltage range is from -VREF to +VREF. If your inputs are within these specifications then it should work.