Test circuit for INA114 instru. amp?

[runtf50]

Hi,

I have several INA114 instrumentation amps that I want to test (that is, they are "used" components and I want to check whether they are OK to use in another circuit). What is the most simple test setup I can use to check them out? I have a VOM, a USB scope, signal generator, a lot of various resistors, 12V batteries, etc.

Best Regards,

David

 

[flat5]

Data sheets often include test information.

 

[runtf50]

I wasn't planning on testing against specs, or anything like that - Just basic "Functions" vs "Does Not Function" testing. It's been 30 years since I've done this sort of thing (I'm trying to help out a friend who has absolutely no hardware experience). I guess I'll just stick in a gain resistor, connect supply voltages and an an input DC signal and see if I get output that doesn't stick at a supply voltage.

- David

 

[Roff]

I wasn't planning on testing against specs, or anything like that - Just basic "Functions" vs "Does Not Function" testing. It's been 30 years since I've done this sort of thing (I'm trying to help out a friend who has absolutely no hardware experience). I guess I'll just stick in a gain resistor, connect supply voltages and an an input DC signal and see if I get output that doesn't stick at a supply voltage.

- David

Just keep in mind that your input needs a DC path to circuit ground, i.e., you can't use a floating voltage source.

 

[runtf50]

Thanks, Roff - I think you just solved what seemed to be a problem.

Best Regards,

David

 

[Roff]

Thanks, Roff - I think you just solved what seemed to be a problem.

Best Regards,

David

To clarify - you don't need to have either input connected directly to ground. You just need a path. It can be many megohms, since the input bias current is 2nA max.
Both inputs must also be within the input common mode range, which worst case is 4V above the lower supply rail, and 4V below the upper rail.