• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 47 subscribers
  • Views 186 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

INA780B: Two ICs in parallel

AJ Ratzlaff
Prodigy 30 points
Part Number: INA780B

This may seem like a silly idea, but is it reasonable to put two INA780Bs in parallel to increase the measured current of a circuit? My aim is 100A max and this IC solves all the other issues regarding ADCs, voltage measurement, and communications. The obvious issues are needing to address two addresses in software, and also combining values to get the full value of current. That isn't as much of a concern. What are things I would need to know or account for if I were to do this?

  • +1
    TI__Mastermind 31485 points

    Hello Appreciated Engineer,

    Yes this is possible. But it depends on how much board space and heating your system can tolerate. Using the INA780BEVM as a reference, this does not mean you need the area of two EVMs to achieve 100A, but it is recommended to test out a prototype under the worst-case operating conditions (ambient temperature, 100A, minimum possible surface air flow). The nice thing about validating this device/circuit thermal capability is that the device has an on-board die temperature sensor that trigger an ALERT once an internal temperature has been reached, usually 150°C.

    Another thing to consider is how much shunt voltage your system can accept.

    You can certainly make some optimizations over the INA780BEVM by using shorter traces to set the address pins (A0 and A1), but I would use this EVM as a base for the layout with IS+ and IS- pads as close as possible to each other and vias under the devices. Another optimization that could be done is to use conductive filled vias under the device. In the EVM, the vias are not filled or are filled with non-conductive epoxy which is not good at transferring heat from the device.

    Hope this helps. Please post back if you have more questions.

    Sincerely,

    Peter

  • 0 in reply to Peter Iliya
    Prodigy 30 points

    Hey, Peter

    Thank you for this response. I will be sure to test out the EVM and implement good thermal design in my application. I will also leverage the Alert function. This should be an interesting design.

    - AJ Ratzlaff