Using DRV8833 to power MCU

Support Motor controllers/drivers and motors
1

Hi,
Is it possible to power MCU with VMM of DRV8833. If so what is the output voltage at VMM. I’d like to power both the Motors and the MCU with a single battery source.

Thanks,

2

Hello.

Yes, it is possible to power an MCU using the VMM pin. As described in the pinout table on the DRV8833 product page, VMM gives access to the motor power supply after the reverse-voltage protection MOSFET, so it can be used to supply reverse-protected power to other components in the system.

- Patrick

3

Thanks.

1 Like
4

Would motor noise affect the arduino or other mcu when powered from vmm of drv8833?

5

Motors can generate a lot of electrical noise, and that has the potential to interfere with signals like the ones going to and from an Arduino regardless of how you are you are powering it. So, if you notice parts of your system behaving strangely when the motor is active you might consider some of these suggestions for decreasing the impact of motor-induced electrical noise:

  1. Solder a 0.1 µF ceramic capacitor across the terminals of your motor, or solder one capacitor from each terminal to the motor case. For the greatest noise suppression, you can use three capacitors (one across the terminals and one from each terminal to the case).
  2. Make your motor leads as thick and as short as possible, and twist them around each other. It is also beneficial to do this with your power supply leads.
  3. Route your motor and power leads away from your logic connections if possible.
  4. Place decoupling capacitors (also known as “bypass capacitors”) across power and ground near any electronics you want to isolate from noise.

Powering your microcontroller from the same source as your motor and driver does however introduce additional ways for the motor to affect it. For example, if your power supply is insufficient for the motor, then the motor’s inrush current when it starts up could cause the supply voltage to drop to a point where your microcontroller will brown out. (Suggestion 4 above can reduce the chances of that significantly though.)

- Patrick

1 Like
6

Thanks.

1 Like