Comparator circuit for ADC

[djc]

Hi,

I am new to analog circuit. I have to design a circuit for ADC input. ADC may b 10 bit or 8 bit. Now according to ADC input output of the circuit should be 0v from 1v-8v, and from 9v to 13v output should be 6 v flat. How to do that plz guide me.

 

[one25]

First, you should declare what happen if the input voltage is between 8 and 9V, then define "0 volts".

I suppose ADC is connected to a microcontroller, so the problem is quite simple, if you already have a 6V supply on the circuit or more.

You need a divider on input, in order to reduce input voltage under reference voltage for ADC. Then, you compare your ADC value with value matching 9V (?) and update an output pin of microcontroller, driving a fet transistor with a drain resistor towards 6V source. If you don't need exactly 6V, you could put a 6V zenner diode betwwen drain and source.

There are a lot more possibilities... but you have to provide more details.

 

[djc]

Thanx one, how about using a Op amp. take that output is 0 for 1v-9v input and 5v for 9v-13v.

 

[one25]

OOoo, I got it. You don't want to do it with ADC... so is simple... you need a comparator circuit.
Take a look here:
https://www.physics.unlv.edu/~bill/PHYS483/comparators.pdf
https://www.ti.com/lit/ds/symlink/lm311-n.pdf