DRV11873: The behavior without correct PWM input

Hi,

Thanks for sharing the details, I will verify and get back to you .

Thanks and Best regards

Venkatadri S

Hello Venkatadri-san,

Thank you for your quick response.  I'll wait for your comments.

Best Regards,

Yoshikazu Kawasaki

Hi Yoshikazu Kawasaki-San,

Even though device responds t0 PWM frequency below 7kHz we will not recommend as there can be sampling errors.

We have mentioned 7kHz to 100kHz with verified data.

Instead of 0Hz, drive stable 0V on the pin then motor will not start.

Hello Venkatafri-san,

Thank you very much for your comments.

> Even though device responds t0 PWM frequency below 7kHz we will not recommend as there can be sampling errors.

So, the root cause of the uncertain of the rotation direction I referred to in my first comment is no PWM input and the issue is expected?

> Instead of 0Hz, drive stable 0V on the pin then motor will not start.

Do you mean PWM input between 7kHz and 100kHz is the only way to control the rotation speed whatever the other pins are?

Best regards,

Yoshikazu Kawasaki

Hi Yoshikazu Kawasaki-San,

Please try above 7kHz and let me know if the uncertain rotation goes away? use any frequency above 7Khz and below 100kHz.

Can you clarify what "other pins are"?

Thanks and Best regards

Venkatadri S

Hello Venkatadri-san,

Thak you for your quick response.

The other pins I meant is like FS pin, CS pin or FR pin other than PWMIN pin.  I understand PWMIN has to have PWM input between 7kHz and 100kHz whatever the input pins other than PWMIN pin are.  If I'm wrong and the device can work without PWM input, please tell me exactly how input pins are set.

Best regards,

Yoshikazu Kawasaki

Hi Yoshikazu Kawasaki-San,

Input pin CS is for current limit, FR should be either high or low based on the direction of rotation.

For high speed FS will be tied to high, for low-speed FS will be tied to low.

Thanks and Best regards

Venkatadri S

Hello Venkatadri-san,

Thak you for your quick response.

I know how the input pins are used from the datahseet.  What I'd like to confirm is if there is no way to control the rotation speed other than PWM input.  From the information you gave me this time, I'll repy to my customer that there is no way other than PWM input which needs to be between 7kHz and 100kHz.

Best regards,

Yoshikazu Kawasaki