DRV8243S-Q1LEVM: Increased VM in fast decay mode

Kei Kuwahara

Expert 5320 points

Part Number: DRV8243S-Q1LEVM

Hello team,

My customer is using DRV8243 to drive solenoid. (They are driving the solenoid with H bridge)

However, they are experiencing increase in VM (up to 35V) when fast decay mode.

Is there any ways to reduce the increase in VM?

Would switching between slow decay and fast decay (mixed decay mode) during the brake work?

Best Regards,

Kei Kuwahara

over 1 year ago

0 Audrey Kuehler over 1 year ago

TI__Intellectual 980 points

Hello Kei!

Thank you for reaching out.

This VM pumping is happening because the VM bus is charging higher as the current is flowing into the power supply.

I would recommend decreasing the PWM duty cycle more gradually during braking.

We also have an FAQ that discusses this concept in more detail:

https://e2e.ti.com/blogs_/b/industrial_strength/posts/art-of-stopping-the-motor-vm-pumping

0 Brian Dang over 1 year ago

Genius 5040 points

Hi Kei,

Kei Kuwahara said:
My customer is using DRV8243 to drive solenoid. (They are driving the solenoid with H bridge)

However, they are experiencing increase in VM (up to 35V) when fast decay mode.

How is the solenoid 2 terminals connected to the driver output? Only one output and to GND or VM, or between two output? If connecting to one output and GND or VM, then bumping VM should not happen.

Brian

Motor drivers

Motor drivers forum

DRV8243S-Q1LEVM: Increased VM in fast decay mode