INA240-SEP: negative rail current measurement

Arun Gopalakrishnan

Part Number: INA240-SEP
Other Parts Discussed in Thread: INA240, INA901-SP

hi,

Is it possible to measure the output current of negative rail in +/-15V DC-DC converter using INA240-SEP current sense amplifier?

If possible please explain the connection?

thanks

Arun

0 Kirby Kruckmeyer96848 over 5 years ago

Hello Arun,

The INA240 common mode only goes down to -4V, so you cannot connect the inputs directly to the -15V bus.

You could use the INA240 by putting voltage dividers on the inputs. This will impact the resulotion of the currrent monitor to some extent.

You could also reference to the -15V rail, but your output would be negative.

A good alternative for a space grade part would be the INA901-SP whose common mode reaches down to -15V.

Kirby

0 Arun Gopalakrishnan over 5 years ago in reply to Kirby Kruckmeyer96848

Hello Kirby,

thanks for the detailed help.

INA901-SP seems to be a good option for me.

thanks,

Arun Gopalakrishnan

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