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.

DRV8231: Unexpected H-Bridge Output Behavior on DRV8231DSGR

Part Number: DRV8231

Dear Texas Instruments Support Team,

we are evaluating the DRV8231DSGR motor driver and have observed an unexpected behavior on the H-bridge outputs.

During testing, when both input pins are set to logic low (IN1 = 0 and IN2 = 0), we expect the outputs to be in high impedance state as described in the datasheet. However, in our setup this does not happen.

When we apply external pull-up resistors (10k ohm) to both outputs, the voltage increases but does not reach the pull-up supply voltage. This suggests that there may be an internal impedance or leakage path inside the device.

Test conditions:
VM = 24 V
VR = 3.3 V
ISEN connected to GND
All other pins connected according to datasheet recommendations

We tested multiple devices of the same part number and observed the same behavior on all samples.

Could you please confirm if this behavior is expected, or if there are additional configuration requirements or operating conditions that we may have missed?

Thank you for your support.


  • Hello,

    Thank you for your question.

    Please allow us some time to review and we will reply within a day or two.

    Best,

    David

  • Hello,

    This is expected behaviour of DRV8231. Hi-Z in this case does not mean floating, only that the FETs are not driven.

    For your second question, Yes, there is inherent leakage current from the body diode and some through the ESD protection circuits. 

    Let me know if I was able to answer your questions or if there is anything else.

    Best,

    Jason