DRV11873: when motor speed increase, it will add the noise into the supply power.

Amelie Zheng

Part Number: DRV11873

Hi Team，

When the motor speed is adjusted to 20hz or above, There will be noise added to the input power supply.

In the following picture which is 20hz, you could see the noise plus in the supply power. When the frequency is 10hz, no noise plus.

When the speed is 10hz, no noise in the supply power.

Do you have some advice about that?

over 3 years ago

0 Cole Macias over 3 years ago

TI__Mastermind 18900 points

Hello Amelie,

Does the signal line up with any of the other waveforms? Perhaps on U, V or W?

10Hz and 20Hz is pretty low, what is the corresponding PWM duty cycle? Is the frequency on PWMin does not change the speed but the duty cycle does.

Best,

-Cole

0 Evan Guo over 3 years ago in reply to Cole Macias

Prodigy 10 points

Hello Mr. Cole Macias

The motor runs at 10Hz or 20Hz.

The frequncy of the PWM is 10kHz and the duty cycle when motor runs at 10Hz is 41%, when at 20Hz is 77%.

0 Amelie Zheng over 3 years ago in reply to Cole Macias

TI__Genius 10865 points

Hi Cole,

Evan is our customer. Could you kindly help for this?

0 Cole Macias over 3 years ago in reply to Evan Guo

TI__Mastermind 18900 points

Hello Evan,

Understood, most be a very low Ke motor.

Again, does the signal line up with any of the other waveforms? Perhaps on U, V or W? What is the fundamental frequency of the noise? The oscilloscope picture does not have the units per division for the horizontal or vertical boxes so I cannot say if it lines up with any expected sources of noise that could be generated by the device.

Best,

-Cole

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DRV11873: when motor speed increase, it will add the noise into the supply power.