INA226: schematics reviewed for the negative voltage sense

Henry Wang3

Part Number: INA226
Other Parts Discussed in Thread: TIDA-00313, INA238

Hi Sir,

My customer refer to the TIDA-00313 Basic Block Diagram to do the INA226 application circuits for voltage sense from -23V to +36V.

Could you please help to review the schematics is available or not?

Programmable power system_V1_0924.pdf

*The U702 is monitored the net-name "GNA_INA-7.7V" is equal the -7.7V or not.

And the net-name "VS_INA" is 4.7V.

*The voltage sense circuit from -23V to +36V.

over 2 years ago

0 Javier Contreras4 over 2 years ago

TI__Mastermind 26475 points

Hello Henry,

I see two issue with this design. The first is the GND_INA pin must be the same voltage as the lowest voltage of VBUS or Vin+ and Vin-. From the TIDA-00313 you can see it is connected to -48V. So from your example it should be -23V as that is the lowest voltage.

The other issue is the VCM Range. For the INA226 the VCM range is from 0 to 36V this is relative to the GND_INA pin. So you can only go 36V above the GND_INA pin.

If you are able to connect the GND_INA pin to your lowest voltage possible of -23V you could use the INA238 in its place as it has the ability to go 85V for the VCM voltage above the GND_INA pin.

Regards,

Javier Contreras