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INA226: Current measurement error with PWM motor driver

Part Number: INA226
Other Parts Discussed in Thread: INA301, INA240, ADS1013, ADS1015


For our design the INA226 is used to monitor currents for two bidirectional motors run by a TI motor driver (DRV8432) in full bridge configuration, and the common mode voltages for the motors are 0 and 24V for one driver while 0 to 12V for the other driver during each cycle of PWM.  In the INA226 datasheet the typical common mode voltage is 12V, but the maximum value is not specified.  What is the maximum operating common mode voltage for INA226?  Is the 24V common mode voltage too large for that part?  We do not see any issues with current reading from the 12V common mode voltage motor.  However, there is a difference in the way how we run the two motors; the 24V motor runs at 33.33 kHz with a 80% duty cycle PWM while the 12V motor runs with a 99.9% duty cycle.  Our problem is that the 24V motor reads very low current (less than 50 mA) in the forward direction even though the motor runs as it should (about 500 mA).  As for the reverse direction, we read only the half of the motor current at 250 mA.

In summary I would like to find out if the 24V common mode voltage is too high and if a PWM may cause the incorrect current reading. 

Is there any other application guidance for this situation that you can offer?

Best regards,