Question

[shahzaib198]

Sir i need to know the reason for this question:

Well sir i have made a logic probe for TTL using Operational Amplifier, But sir
i am not getting the point that if we can make it using two resistors as well
then whats the Advantage of using Operational Amplifier.

Thanks, Please Reply me Urgently @ [email protected] or here.
 

[hemlig]

The answer to that is very simple:
Impedance

if you don't mind measuring errors then it is ok to ignore the impedance..

but the op is there for the reason to keep the impedance high at the probe.
(low impedance at the probe will result in measuring errors)