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INA3221: These pin not used, can be leave floating, no connection?

Part Number: INA3221

Hi team,

My customer has their design using this device INA3221,

Customer has some questions on the connection with below highlighted pin, 

Are these pins be OK to leave floating, if unused? Datasheet not mentioning unused connection.

  • Hello Oliver,

    Thanks for reaching out on the forum.  By floating the output of the digital pins it would be similar to using a massively large pull-up that is as great and most likely greater than the RDSoff resistance of the mosfet that is open drain.  So you might see some potential at these points, but the current leaking through the drain to the source should be quite small as RDSoff is likely in the MΩ range and the parasitic leakage path resistance from a non zero potential to one of these digital outputs depends on the air and FR4 distance between that potential and the digital output pin.  Also as these pins connect to mosfets and there should be very little current passing from either gate to drain or gate to source.  Consequently, leaving the digital outputs floating should be fine. As for VPU, the design engineer I spoke to recommended to have it connected to the supply voltage as floating it may lead to the device consuming more power.