use of INA169 High-side current sense on dual polarity power
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use of INA169 High-side current sense on dual polarity power

by silicon_ghost on Wed Feb 27, 2013 11:11 am

Looking at the spec sheet for the INA169 breakout board, it isn't clear to me if I can use this in my project. I have +15V and -15V supplies and I want to monitor current load in each of them (or combined if that provides a solution). It is obvious that it will work for the +15V supply but I can't tell if I'd blow the IC trying to interface to the -15V rail.
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Re: use of INA169 High-side current sense on dual polarity power

by adafruit_support_mike on Wed Feb 27, 2013 6:12 pm

Nope, it won't work. The INA169 is designed strictly for high-side current. The output comes through an NPN transistor that gets its power from the high side of the sense resistor, so running it on the low side wouldn't give you enough headroom to make it work.

The INA212 is a high/low sensor from the same general family though:

http://www.mouser.com/ProductDetail/Tex ... bNztSgM%3d
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