I am two single ended signals from the outputs of two Instrumentation amplifiers driven +/-5V. I call them DIFF1, DIFFGND1, DIFF2, and DIFFGND2. DIFFGND1 and DIFFGND2 remains separate and isolated from supply GND using 1nF caps.
I am planning to feed these signals to ADS1299. The ADS1299 will be supplied using +/-2.5V. I have isolation between instrumentation supply and ADS supply to make sure that input to ADS will never go beyond its supply rail.
Here is the way i am planning to connect the signals from instrumentation amplifiers to ADS1299.
ADS1299 pins ---------> INA single ended signals
IN1P ----> DIFF1
IN2P -----> DIFF2
(IN1N+IN2N ---->DIFFGND1+DIFFGND2) ---> Driven by a low noise buffer into the middle of the rail of ADS1299 which is ground.
I would appreciate if anyone can comment on the configuration. It would be nice to have some idea about noise numbers it could results in.
Thanks
Sankar
