• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 30 subscribers
  • Views 554 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Is DRV8816 good choice to drive my motor?

Mark Sievel
Prodigy 10 points
Other Parts Discussed in Thread: DRV8816, DRV8800, DRV8816EVM

We are planning to use the DRV8816 to drive small brush motors. Our application is a little unique. We have access to only one lead of the motor. The other lead of the motor is switched by other means between +12VDC and GND. So we will connect the one motor lead we have access to to the half bridge, and can either source current to the motor, or sink current from the motor, or do nothing based on the state of the half bridge, and the state of the other motor lead. We will be able to drive 2 motors with the two half bridges.

Our motor is a 12 VDC brush motor. We do not plan to PWM.

We have mocked up a  driver and motor, and have had some problems. We think the driver enters fault mode, probably due to poor heat sinking.

The motor draws about 1.5 A peak when starting, after about 75 msec, the motor running current drops to about 200 mA. The motor is only powered for about 2-4 sec. Only one of the two half bridges is likely to be powered at a time.

If we follow the datasheet guidelines for board layout, will we have thermal problems? We must operate from -40C to about 83C. Do we need more safety margin?

  • 0
    TI__Guru** 114905 points

    Hi Mark,

    The DRV8816 will work in your application. You might also want to examine the DRV8800. It has similar features, but may not work if under all combinations of driving the two motors. If you decide to examine the DRV8800, please pay attention to the control logic table on page 13 of the datasheet.

    In addition to following the guidelines in the datasheet, we also recommend that you look at the DRV8816EVM. It is available for purchase through the estore and allows an early evaluation without having to create your own PCB. The EVM folder also contains the schematic and layout used, which can guide you through the process of creating your own.