DRV11873: Motor speed issue

Cherry Zhou

Part Number: DRV11873

Hi team,

Here's an issue from the customer may need your help:

The motor speed cannot be increased to around 5000. With a 5V 150mA supply, increasing the supply voltage or increasing the duty cycle, the motor will stop spinning, what is the reason for that? Is it related to the DRV11873 's speed limited or the output current is out of range? Could you help check this case? Thanks.

Best Regards,

Cherry

over 3 years ago

0 Aaron Barrera over 3 years ago

TI__Mastermind 26046 points

Hi Cherry,

Can you set FS = 1? What is the PWM frequency used?
Can you set the supply to higher than 150-mA? If there is not enough current, supply can brown out to under 4.1V and this will shut off the device.

Thanks,
Aaron

0 Cherry Zhou over 3 years ago in reply to Aaron Barrera

TI__Mastermind 22235 points

Hi Aaron,

Thanks for your support here!

FS is pulled up to 5V and can reach a maximum of 9500 turns. But by increasing the voltage or duty cycle, the motor speed can no longer increase and will simply stop.

Voltage: 9V, enough current, 20K PWM frequency. Can the speed be increased more?

Thanks and regards,

Cherry

0 Aaron Barrera over 3 years ago in reply to Cherry Zhou

TI__Mastermind 26046 points

Hi Cherry,

You could be coming across a false lock condition, similar to this thread. Does this help?
https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/691434/drv11873-the-speed-issue-9000rpm-10800rpm

Thanks,
Aaron

Motor drivers

Motor drivers forum

DRV11873: Motor speed issue