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DRV8243H-Q1EVM: DRV8243H EVM

Part Number: DRV8243H-Q1EVM

I recently acquired the DRV8243H along with the EVM, and I'm encountering two issues:

  1. Currently, the nFault is triggered when the ITRIP reaches 5A, and I'm struggling to adjust it to a different value. I've attempted modifying the RIProp and changing the ITRIP to various levels, but none of these adjustments seem to resolve the issue.

  2. The motor doesn't operate smoothly; every 2-3 seconds, there's a noticeable lag or spike in its performance. I'm aiming for a clean and consistent operation.

My current hardware configuration is as follows:

  • Diag Level 1
  • SR Level 1
  • Mode Level 3 (PWM Mode)
  • RIPROP 1K OHM
  • ITRIP Level 5

I would appreciate any insights or suggestions to address these issues. Thank you!

  • Hello Avi,

    Thanks for the post. 

    1. For the mentioned 5 A target current what was the supply voltage used? Based on your description it appears you have hit the thermal shutdown TSD in your application test at this current. 

    2. The device is set in auto-retry mode after a TSD based on your configuration. Hence you're seeing this in the not so smooth output because every time a TSD happens the bridge is disabled and enabled after a few milliseconds per the datasheet specification. 

    You can use the die temperature estimator and plug-in your application voltage and current over time and see if the device will hit TSD. https://www.ti.com/tool/download/SLVRBI3. I think you may have a much higher in-rush current at startup that causes the device to hit TSD, this can happen very fast. SR level setting has an impact as you may notice by changing SR values in the die temperature estimator. Usually SR LVL 1, 24.5 V/us should be good. When SR is changed the device must be either go through a sleep-wake cycle or a power cycle.

    What is the version of the GUI used for testing? Version 1.0.1 is the latest. Be sure to perform a Firmware update with the latest GUI. The issues you encountered in not due to GUI version thought. Just that it would be best to use the latest for device evaluation. Thanks.

    Regards, Murugavel 

  • Thank you for the response Murugavel!

    1. Using a 24V power supply.

    2. Experiencing non-ideal output behavior even at low currents (e.g., 1A). It seems unrelated to TSD (Over Temperature Protection).

    3. Initially, we utilized the GUI to set up the DRV, and it worked fine. However, we later lifted the resistors connected to the MCU and directly wired our MCU instead.

     
    I have a question regarding the recommended PWM frequency for our DRV setup. Currently, we are operating at 24 kHz, and based on the documentation, there shouldn't be any issues up to 25 kHz.

  • Hello Avi,

    We have tested with 25 kHz PWM and it worked as expected no issues with 24 kHz. I suspect the SR may not be set correctly. As well as double check the settings. This product is currently used by several customers in automotive and non-automotive applications. 

    Regards, Murugavel

  • Meaning we are working per the recommended configurations both on the hardware and software level. I'm not sure what else it could be. Is there a Temperature/Current chart we could review to make sure that we're operating in the right range?

  • Like I mentioned earlier you can use the die temperature estimator and plug-in your application voltage and current over time and see if the device will hit TSD. https://www.ti.com/tool/download/SLVRBI3. This Excel will generate the chart for you.

    Regards, Murugavel