This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

INA190: the driving current of REF pin

Part Number: INA190
Other Parts Discussed in Thread: TINA-TI

Dear experts,

Customer is using one LT6656 (1.25V) driving 8 INA190's REF pin.

They're wondering the how much the driving current of REF pin is to ensure LT6656 could drives them all.

Thank you.

Best Regards,

Cindy

  • Hi Cindy,

    the TINA-TI simulation shows a very low current through the REF pin. Not sure whether this is correct or not. But could be valid, as the INA190 is a low power amplifier drawing only 50µA supply current:

    But there's another issue. The current through the REF pin is bidirectional. So the voltage reference must not only deliver current but also absorb current. Because of this a simple OPAmp buffer as shown in figure 37 of datasheet might be the better choice. Or a dummy load resistor could be mounted from the output of LT6656 to signal ground so that the LT6656 is always sourcing current and is never going into the reverse current mode.

    Kai

  • Cindy,

    Kai is correct here in that the models parameters were designed to show typical performance here, including the reference pin current. Peter also took the liberty of capturing some test data in this forum post for the INA190. The current for each device should not exceed a few uAs.