Part Number: DRV8353RS-EVM
Hello,
I am a student on a team developing BLDC motor controllers for a packaging-sensitive application. We've purchased a DRV8353RS-EVM to evaluate the gate driver chip. There have been issues:
First Test: We connected our motor and ran the driver using the provided GUI. The motor started spinning, but we realized we had not set the number of pole pairs correctly and turned off the motor through the GUI.
Second Test: We set the number pole pairs correctly (15 pole pairs). The motor started twitching and making high-pitched noises unexpectedly, so we cut power to the system.
Every Subsequent Test: The startup routine will not generate a good profile of the motor (nonsensically high phase resistances). The chip is throwing a GDUV fault for gate drive undervoltage/charge pump undervoltage. We probed the test points and found the following:
- Params: 20V DC bus; ~0.15 Ohm, ~0.3mH motor; split-rail configuration (default)
- Load nodes (MOTA, MOTB, MOTC) are all floating at ~17V -- is this normal?
- Charge pump voltage at ~1.7V (relative to load) -- abnormal
- Low-side gate drive voltage at ~2.8V -- abnormal
- The DRV8353RS chip gets very warm very fast
- The power supply reports a 180mA draw without the motor spinning
- LM5008 regulator output is at 12V -- nominal
- DVDD (logic level) is at 5V -- nominal
- We can see the motor back-emf on all the load nodes when we spin the motor
The motor is still functional using a different controller. The IDRIVE settings are at 150mA/300mA (default).
We suspect the DRV8353 chip is broken, but do not understand the root cause. What other tests can we do to understand what is going on? Is the chip still OK and something else is wrong? How can we get a replacement chip or full board?
Best,
Karthik
