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DRV8839: MOTOR VIBRATION WHEN OPERATE 100% DUTY CYCLE

Part Number: DRV8839

Hello Sir,

Good Morning,

Task : PWM based Motor Drive using Motor Driver IC

As above mention project we working, we are facing issue of MOTOR Vibration while motor operate at 100% duty cycle.

MCU :

a>  PWM output Freq : 2 Khz

b>  Duty Cycle             : 100%

MOTOR Specification : 

a> Voltage : 3 Vdc

b> Current : 0.15 A

We attach PWM Driver IC configuration,

        

We test with different PWM freq. such as 1Khz, 5Khz, 10Khz, 15Khz, 20Khz but get same issue.

Motor Only vibrate at 100% duty cycle.

Need Help , I am not get any idea what is issue.

Thanks & Regards

Chintan Patel

  • Hi Chintan,

    Can you describe the motor vibration in more detail?
    Have you examined the OUT1 and OUT2 to confirm the outputs remain active?
    If the outputs do not remain active, please examine the VM and VCC supply to confirm the voltage remains stable.
    What value bulk capacitance do you have on the VM supply?
  • Rick Duncan said:
    Hi Chintan,

    Can you describe the motor vibration in more detail?
    Have you examined the OUT1 and OUT2 to confirm the outputs remain active?
    If the outputs do not remain active, please examine the VM and VCC supply to confirm the voltage remains stable.
    What value bulk capacitance do you have on the VM supply?

    Dear

    Thanks for your promoting reply on motor vibration issue.

    Bellow mention detail about motor Specification

    CMP17B Micro Vacuum Pump Specifications

    Free Flow     Max Vacuum  Max Pressure   Current    Voltage

    Model:CMP17B       500mL/min      --400 mbar     700 mbar      0.15 A     3 VDC

    Motor Construction:    Brush Motor

    Diaphragm Material:   Butyronitrile

    Pump Material:       PPS

    Temperature Range:  37-122F(5—50℃) 

    Weight:               33 grams

    Size:              18*30*45mm

    Life:                  1000 hours

    Sound Level:           65 dB (1 meter  space)

    Certification:           RoHs

    Stored Temperature:     --40℃ to 85℃

     

    About our system 

    1. Supply of VM and VCC is 3.3V DC

    2. We use Li-ion battery for our application 

    3. To Achieving 3.3V DC for regulation we use "LP5912-3.3DRVT"

    4. In DRV8839 IC  0.1uF/16V ceramic is use at both side input and output 

     

    1> Have you examined the OUT1 and OUT2 to confirm the outputs remain active?

    Ans: Yes Sir, I shown on CRO , OUT1 and OUT2 remain active 

     

  • Hi Chintan,

    Can you provide scope captures of OUT1 and OUT2 when the vibration occurs?
    Also have you tried running the motor directly connected to a power supply? Does the motor vibrate at 3.3V?
  • Hello Rick, 

    Thanks for your reply.

    Below attached image describe signal  between output 1 and output 2.

    We checked with 3.3v power supply to motor directly then vibration is same as 100% duty cycle.

  • Hi Chintan,

    If the motor vibration is present when connected directly to the power supply, please work with the motor vendor to determine the reason.