Input offset voltage level of AD8629

Thanks Harry,

But customer have suspected the input offset voltage of AD8629,

So 90mV output is suspected in his circuit.

What is the way of the input offset voltage measurement?

And as for your enclosed "BadCircuit.pdf", it means that my enclosed schematic bad , correct?

Thanks Kaos

Kaos,

  The circuit is doing exactly what you asked it to do.  You have built a circuit that has a gain of +1,

see attached.  The second op amp is set for a gain of +10.  Write the equations or simulate the circuit.

The offset of the AD8629 is a few microvolts.

Harry

Kaos,

  Yes, your circuit is bad and will not do what you want.

There is a standard "op amp test loop" that will allow measuring several parameters.

See figure 1 in:

Simple Op Amp Measurements: Analog Dialogue: Analog Devices

Harry

Thanks Harry.

I will suggest your circuit for offset voltage measurement to our cusotmer.

Kaos

Sorry, our customer replied for your answer.

This is not customer's answer he said.

I found my misunderstanding for this.....

So I will put the new sled here Amplifiers group.

Please see there later.

Thanks Kaos