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INA310A-Q1: TINA-TI Simulation of bidirectional measurement setup as per datasheet does not work

John Hermann
Prodigy 10 points
Part Number: INA310A-Q1
Other Parts Discussed in Thread: INA301

Tool/software:

Dear all,

I set up the simulation for bidirectional current measurement as per datasheet, figure 7-6. However, the simulation does not work. It works fine, however, when only connecting one INA301. 

I used the simulation model from this thread: INA310A: TINA-TI model for INA310A - Amplifiers forum - Amplifiers - TI E2E support forums

Is there a problem with the simulation model?

Simulation parameters: Current is triangular from -4000 to 4000 amps. Shunt is 1 µohm. With the INA301B5 (Gain of 500)  this should lead to a voltage swing of -2..2 volts. 

Best regards,

John

  • 0
    Prodigy 10 points

    Dang, wrong screenshot. I meant to post this image:

  • +1 in reply to John Hermann
    TI__Mastermind 23685 points

    Hey John,

    I think the issue here is how you have set up the load line. The valid common mode range of the INA310 is -4V to 110V. The way you have set this up, you are running a fixed resistance and variable voltage, and requiring V=IR to set the load current, which means your voltage is set as high/low as +/-400V. On the high side, as nearly no voltage is lost by the shunt, this is effectively the common mode of device, and it is travelling out of the recommended operating operating area via this setup.

    I recreated the circuit using a load current setup with a constant VCM, and things look to be in order. I attached a copy of my setup if you'd like to have a look, but moving to this style of setup should work:

    INA310 Bidirectional.TSC

  • 0 in reply to Carolus Andrews
    Prodigy 10 points

    Carolus,

    yes, of course, you are right. That resolved my issue. I just moved the load resistor to the high potential and therefore transformed the circuit to low-side-measurement. Now it works perfect. Thanks again, I totally missed that.

    Best regards

    John