In-system calibration of a INA169 μA current sensor
John Peck writes about using an Adafruit INA169 breakout board for low current testing in a circuit:
One of my projects will be powered by a battery, and will sleep for long periods while it waits for user input. My battery life will depend on this sleep current, which might be about 10 µA. My handheld meter will measure this, but it suffers from mediocre common-mode rejection when I use it to measure high-side current.
I really wanted to probe my sleep current and send it directly to an oscilloscope. These INA169 breakout boards seem like a convenient way to make this probe, but using them raises calibration, noise, and bandwidth questions. I want to describe how I put down a simple calibration circuit to give myself some confidence in this measurement.
See John’s application and results in the post here.
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