DRV8301 (pin-6, fault) go low once EN_GATE is activated

Jordda

Other Parts Discussed in Thread: DRV8301

Hi,

We meet the trouble in FAULT error with no PWM into DRV8301. Based on DRV8301 EVM board's schematic, we make our board. When power on our board without EN_GATE, pin-6 is kept HIGH as normal. But when enabling EN_GATE, pin-6 is going to LOW. I've checked GVDD is not higher than 16V. As the temperature issue, I believe it's not high. Do you have any advice how to resolve this FAULT error issue ?? Thanks!

PS: Another question is SPI_VDD. Do you think 3.1V is enough high to activate DRV8301's SPI function? Does it impact anything ?

over 12 years ago

0 Nicholas Oborny over 12 years ago

TI__Mastermind 21320 points

Hi Jordda,

Do you have a schematic/layout of your board that I can see. Can you explain the setup you are using (power supply/motor)?

I believe 3.1V should be fine, is this the same voltage level the controller is running at?

-Nick

0 Nicholas Oborny over 12 years ago

TI__Mastermind 21320 points

Also,

Here is an image with a list of reasons FAULT/OCTW could be asserting. This is found Page 16 of the datasheet and may be a good first step in trying to find the cause of the problem

-Nick

0 Ryan Kehr over 12 years ago in reply to Nicholas Oborny

TI__Guru 55615 points

Jordda,

After EN_GATE, the nFAULT pin will cycle low for ~2.18ms and then come back high. This is expected and part of the startup period for the device. The "start-up time" is specified on page 9 of the datasheet and is typically 5ms. During this time, it is not possible to communicate with the device over SPI.

I have attached a timing diagram of the relationship between EN_GATE and nFAULT.

On the other question, VDD_SPI should be connected to the same voltage as the MCU that is the master SPI device.

0 Jordda over 12 years ago in reply to Ryan Kehr

Intellectual 665 points

Hi Ryan,

Thanks for this useful timing diagram.

0 Jordda over 12 years ago in reply to Nicholas Oborny

Intellectual 665 points

Hi Nick,

Thanks for this important remind.

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DRV8301 (pin-6, fault) go low once EN_GATE is activated