DRV8906-Q1: DRV8906 to drive BLDC

user5913722

Prodigy 120 points

Part Number: DRV8906-Q1
Other Parts Discussed in Thread: DRV8311

I want to use DRV8906 to drive two three-phase BLDC motors，is it possible? are there any risks? thanks!

5 months ago

0 Shinya Morita 5 months ago

TI__Mastermind 30715 points

Hi,

Thank you for your questions. We consider that DRV8906-Q1 cannot be used for BLDC application, because;

-DRV8906-Q1 does not have PWM external input pin. Therefore, All OUTPUTs should be changed via SPI bus. SPI communication delay always exist to change output.

-Internal PWM generator's frequency is up to 2KHz only.

I suggest to pick BLDC device from here.

Brushless DC (BLDC) motor drivers | TI.com

Please generate new E2E post if you have question about these BLDC devices.

regards

Shinya Morita

0 user5913722 5 months ago in reply to Shinya Morita

Prodigy 120 points

thank you for your reply

1. According to this document- "Driving BLDC Motors with PWM Generation Mode", SPI frequency up to 5MHZ, so SPI delay shall be OK, right?

2. Normally my maximum motor speed will be 1200RPM, What PWM frequency do you suggest? any problems with low PWM frequency?

https://www.ti.com/lit/ab/slvafl7/slvafl7.pdf?ts=1712626845545&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FDRV8311%253FkeyMatch%253DDRV8311%2526tisearch%253Dsearch-everything%2526usecase%253DGPN-ALT

+1 Shinya Morita 4 months ago in reply to user5913722

TI__Mastermind 30715 points

Hi,

Thank you for your further questions and interested in DRV8906-Q1.

1. DRV8311 is developed by another product group who develop BLDC motor driver. DRV8906-Q1(our brushed DC motor driver group device) is not designed to operate like DRV8311 BLDC motor driver.

2. DRV8906-Q1 is not designed for BLDC motor driver. DRV8311 can support PWM up to 200KHz like normally BLDC motor driver can support.

DRV8906-Q1's PWM generator is designed for LED driver mainly. Even brushed DC motor, 2KHz is too slow normally and may hear audible noise. >20KHz is required to avoid audible noise. And to support rpm speed with BLDC, normally PWM frequency is higher than 20KHz..50KHz, 100KHz, 200KHz.

By the way, DRV8906-Q1 does not have current sense function like DRV8311. FYI.

TI do not restrict customer to use DRV8906-Q1 for BLDC, but I guess this device probably end up cannot be used in your BLDC application. We would like to recommend to investigate our BLDC motor diver family.

regards

Shinya Morita

Motor drivers

Motor drivers forum

DRV8906-Q1: DRV8906 to drive BLDC