3 vs 6 PWM on DRV8301

MARK PESACH

Intellectual 850 points

Other Parts Discussed in Thread: DRV8301

i am using the drv8301 to drive my motor with Field Oriented Control.

i understand that with FOC this is possible with only 3 pwm mode.

but i would be happy if someone can please explain if there any advantage with the 6 pwm method obver the 3 pwm.

best regards.

Mark.

over 9 years ago

0 Rick Duncan over 9 years ago

TI__Guru** 114905 points

Hi Mark,

Our experts have been contacted and should reply soon.

0 Nicholas Oborny over 9 years ago

TI__Mastermind 21320 points

Hi Mark,

Pro:

3-PWM mode allows you to reduce the required PWM resources from the MCU. The DRV8301 would handle the dead time generation and complementary low-side signal.

Con:

3-PWM does also not allow for the half-bridge to be placed in the Hi-Z state (generally not required for FOC). You would have to switch the DRV8301 back to 6-PWM mode for Hi-Z.

0 MARK PESACH over 9 years ago in reply to Nicholas Oborny

Intellectual 850 points

Hi Nick

thank you for your reply,
i just wanted to ensure that for FOC there is no advantage with 6 pwm

best regards
mark

0 Nicholas Oborny over 9 years ago in reply to MARK PESACH

TI__Mastermind 21320 points

Only advantage I could see is being able to add dead time in software. DRV8301 requires a resistor to set the dead time.

But I don't see this being any problem. Dead time should not need to be adjusted dynamically.

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3 vs 6 PWM on DRV8301