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INA146: Cross reference? Either TI or other manufacturer, but same pinout and SOIC8 package?

Part Number: INA146
Other Parts Discussed in Thread: INA149, INA148, INA143

We found out that TI will not be able to produce any INA146UA High Voltage, Programmable Gain Difference Amplifier chips until July, 2023. Brokers have proven very undependable. Is there any cross reference, or alternate, part available with the same pinout and SOIC8 package from any manufacturer? We are trying to avoid a PCB respin.

Thanks for any assistance.

  • We have INA143 with gain between 1/10 and 10 and unity-gain difference amplifiers, INA148 and INA149, that may be configured to be pin-to-pin compatible to INA146 and available in SO-8 package. 

  • We looked at those options, but the issue is we need the programmable gain stage, as we use a gain of approximately 0.14. We could change some resistor values and use a gain of 0.1, but the inputs, SENSE and REF pins of the INA143 are in the exact opposite location from the INA146 when using it as a G=0.1 Difference Amplifier.

    Our input voltages are 24 - 60Vdc.

    Our circuit:

    The INA143 with a gain of 0.1 requires the input signals to go to pins 5 and 1, with 3 to ground and 6 shorted to 2.

    This is why we are looking for an almost exact alternate, or cross reference, for the INA146, or at least something usable in our circuit layout (resistor values can change).

  • What is the input common-mode (Vcm), input differential voltage (Vdiff) and the supply voltage of your application?  Unfortunately, we do not have a difference amplifier with exact pinout of INA146. 

  • What is the input common-mode (Vcm), input differential voltage (Vdiff) and the supply voltage of your application?  Unfortunately, we do not have a difference amplifier with exact pinout of INA146. 

  • Thank you for looking into our issue. We could respin the PCB and use a different circuit, but that is worst case, as it involves a lot of customer retesting, compliance, and other parts may also become unobtainable. That is why we are trying to find workarounds with the PCB we have. 

    When operating correctly and after power-up, one input (PWR_IN) is going to be from 24V to 60V, the other input (PWR_24_60) will be at 0 to 60V. Vcm max. = 60V, Vdiff max. = 60V, Vsupply = 24V.

  • David,

    One could use INA149 with two external connections as shown below to make it look like INA146 in a unity gain BUT on Vsupply of 24V this would allow maximum differential voltage of only 21V so the input would have to be attenuated accordingly. Otherwise, I believe you'll be forced to spin the new PCB.

  • Again, thank you for the responses. We really need the chips to become available again.