LM2901: LM2901M appear to have large offset

Jacob

Part Number: LM2901
Other Parts Discussed in Thread: OPA4322

I am having some trouble with an LM2901M which appears to have an offset of at least 165 mV though the datasheet specifies +/-3 mV.

This is with 7.2V input to the circuit, which causes the output to oscillate erratically. At 7.1V it is low and at 7.3V it is high.

Can you spot something that I am missing in the circuit, or could the LM2901M really have that large an offset?

Thanks!

over 5 years ago

0 kai klaas69 over 5 years ago

Guru 140200 points

Hi Jacob,

you violate the common mode input voltage range of LM2901. This chip can only handle input voltages which don't exceed 3.3V-1.5V=1.8V. But the OPA4322 gives out up to 3.2V! You might need a comparator which can input rail to rail.

Kai

0 Jacob over 5 years ago in reply to kai klaas69

Prodigy 180 points

That would do it. Thank you!

Amplifiers

Amplifiers forum

LM2901: LM2901M appear to have large offset