INA310A: Current sensing with negative voltage

Ulisse_

Prodigy 215 points

Part Number: INA310A
Other Parts Discussed in Thread: TMCS1123, TMCS1126, TMCS1133

Hi,

I need help to use this part as current sensing in negative voltage.

I need to control current in H-bridge in positive voltage rail and negative voltage.

I can use this part? have a circuit testing?

Thank you

8 months ago

0 Mitch M 8 months ago

TI__Mastermind 20815 points

Hello Ulisse,

The INA310A cannot have a negative common mode voltage, but it can have a negative voltage difference over the sense resistor. Here is an app note that we have for doing current sensing in an H-Bridge: https://www.ti.com/lit/ab/sboa174d/sboa174d.pdf

Regards,

Mitch

0 Ulisse_ 8 months ago in reply to Mitch M

Prodigy 215 points

I need to measure current with shunt 70+/- voltage rail 70V+ | GND | 70V-

Have a IC specific TI?

I need to measure this and need help.

Thank you

0 Mitch M 8 months ago in reply to Ulisse_

TI__Mastermind 20815 points

Hey Ulisse,

The INA310A (as well as our other analog out current sensors) are not capable of doing the -70V rail. That being said, we do have a couple options for you to consider:

Use a digital INA with a floating voltage and a digital isolator.
1. example: https://www.ti.com/tool/TIDA-00313
Use a Hall based current sensor:
1. Here are some device options that reject ambient magnetic fields:
  1. TMCS1123
  2. TMCS1126
  3. TMCS1133

Note that if you are trying to measure really small currents, then the digital INA with an isolator may be a better option.

Regards,

Mitch

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INA310A: Current sensing with negative voltage