That is my circuit:
Input: 400V DC
U2_1: LTC1285 (ADC) http://www.farnell.com/datasheets/1575635.pdf
U2_2: IL261 (digital isolator) http://www.nve.com/Downloads/il260-1.pdf
The circuit behavior is:
1: resistive partitor with high precision resistor to decrease the input voltage.
2: zener diode protect from eventually overvoltage.
Now the question:
In point 3 is useful to use a low pass filter for clean the DC on ADC input from eventually high frequency noise? If yes, how can I connect it for a proper functioning?
Is the first time I use an ADC.. thanks in advance!