DRV8312: 3 phase motor driver

Rohit Bhayal

Part Number: DRV8312

Tool/software:

Hii,

In our design we want to use only 2 phase output of IC DRV8312. Can we use only two outputs of DRV8312 IC making third output Not connect(NC).

can you please help?

11 months ago

0 Yara Al Shami 11 months ago

TI__Genius 15025 points

Hi Rohit,

There are instructions in this FAQ that address your question:

https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/1176539/faq-quick-guide-to-debugging-common-issues-in-bldc-motor-drivers

Let me know if you still need help

Regards,

Yara

0 Rohit Bhayal 11 months ago in reply to Yara Al Shami

Prodigy 30 points

Hi Yara,

"Can you please provide detailed pin connections for the DRV8312? I have reviewed the FAQ but still have some doubts."

0 Yara Al Shami 11 months ago in reply to Rohit Bhayal

TI__Genius 15025 points

Hi Rohit,

PWM_x and RESET_x should be connected to GND.

I recommend connecting GVDD_x to the recommended voltage range or you will get a FAULT that triggers for GVDD_UV. PVDD_x should also be connected to the other supplies, but it is not necessary to decouple it with any large decoupling. Just a 1uF or 0.1uF to GND on this pin would be fine.

To avoid BST_x undervoltage protection, you will need to supply the capacitor as recommended, just a small 100nF is sufficient.

OUT_x should be left floating.

Regards,

Yara

0 Rohit Bhayal 11 months ago in reply to Yara Al Shami

Prodigy 30 points

Hi Yara,

As OUT_C is an unused phase, the bootstrap capacitor of the unused phase (BST_C) needs to be connected to GND?

0 Yara Al Shami 11 months ago in reply to Rohit Bhayal

TI__Genius 15025 points

Hi Rohit,

You don't want BST_x to be connected to GND since it is powered by GVDD

I consulted my team further on this question and you can actually keep OUT_x (in your case the unused phase, OUT_C) floating, and tie BST_x (in your case BST_C) to OUT_x using a capacitor. I'd recommend testing with the capacitor tying BST_x to OUT_x but also test both OUT_x and BST_x floating.

Regards,

Yara

0 Sanath P 11 months ago in reply to Yara Al Shami

Prodigy 130 points

Hi Yara,

As OUT C is not connected in above 3 phase motor driver, Can I use it for driving other motor as shown in below diagram (i.e., with 2 DRV8312 ICs, 3 different motors can be driven)? Will it cause any timing or functionality issues?

0 Yara Al Shami 11 months ago in reply to Sanath P

TI__Genius 15025 points

Hi Sanath,

Some issues that may arise is certain protection features will be affected and may not detect faults accurately. If each motor has different voltage requirements that could also cause issues.

It looks like you may be trying to drive brushed motors? If so I would recommend looking into brushed and stepper motor drivers here:

https://www.ti.com/motor-drivers/brushed-dc-bdc-drivers/overview.html

https://www.ti.com/motor-drivers/stepper-driver/overview.html

and if you have any brushed or stepper motor drive related question please make a separate post so it can be assigned to the correct team.

Regards,

Yara

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DRV8312: 3 phase motor driver