Protecting a ADC pin.

Archiver

I am using a MAX ADC to read the voltage from a vehicle and I know
that this is a hard environment. How can I protect the input of the
ADC from spikes and other problems?

I will be using a simple voltage divider. I have seem other people use
OP-AMPS on the input, but I don't understand why. Can someone explain?

Should I use some caps in the input to the resistor network? Would
that help?

Thanks for any suggestions.

-jr

Archiver

A Zenner diode in the input will do the job for spikes.
OP amps generally are used to amplify small signals. For higher voltage
signal values the resistor dividers are fine.
Capacitor in the input will act as a low pass filter, blocking the short
term changes.
ACJacques

James Russo wrote:
>
> I am using a MAX ADC to read the voltage from a vehicle and I know
> that this is a hard environment. How can I protect the input of the
> ADC from spikes and other problems?
>
> I will be using a simple voltage divider. I have seem other people use
> OP-AMPS on the input, but I don't understand why. Can someone explain?
>
> Should I use some caps in the input to the resistor network? Would
> that help?
>
> Thanks for any suggestions.
>
> -jr