Re: Input offset current drift vs. temperature

On Aug 6, 10:11 pm, Tim Wescott <t...@xxxxxxxxxxxxxxxx> wrote:
Kingcosmos wrote:
Does anyone know if the input offset current of an op-amp drifts with
temperature?

Every parameter of an op-amp, including size, drifts with temperature.

Or will it stay within the +/- rating of the data***
spec while the input bias current drifts vs. temperature?

If the data *** guarantees the input offset current over temperature
then it should stay in bounds, yes. Read your data *** carefully.

I think
JEFT and MOSFET bias currents from gate leakage double every 10°C?

Possibly, and it may even matter with a JFET. With a MOSFET it'll go
from negligible at 100C to several orders of magnitude below negligible
at lower temperatures. Meanwhile, your offset voltage will be atrocious.

--

Tim Wescott
Wescott Design Serviceshttp://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details athttp://www.wescottdesign.com/actfes/actfes.html

Most datasheets I see will state a +/- rating for both input bias and
input offset currents, and a graph later in the data*** showing
input bias vs. temperature. I would simply guess that the input
offset currents would drift in the same manner. Rule of thumb maybe.

.

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