Power up/down sequence burning TB6612FNG??

Other Hardware Motors, Mechanics, Power and CNC
1

New to the forum and Arduino - simple project to make a car go forward and backwards.

Basically, I'm using this TB6612FNG driver with the Arduino pro mini. I have the TB6612FNG connected to a 6V, 700mAh battery pack to control a Meccano 4.5V DC motor. I'm using different power sources for the Arduino and the DC motor via TB6612FNG Vm pin.

I wrote a sketch and was able to make it work and properly control the motor. However, the problem comes when I disconnect the battery pack, power off the Arduino, then reconnect the battery pack to the TB6612FNG. As soon as the power connection is made (Arduino is still off), the TB6612FNG burns out and literally goes up in smoke.

Specifically, these are the steps followed to power the project:

  1. turned on the Arduino,
  2. plugged in battery pack to the TB6612FNG,
  3. ran the sketch with no problem and motor was properly controlled,
  4. removed power from Arduino,
  5. removed power from TB6612FNG,
  6. reconnected the TB6612FNG - as soon as the power connection was made, the TB6612FNG went up in smoke.

I find it difficult that the power up/down sequence could be the culprit but can't think of anything else.

I've gone through 2 of these already. The first one, I had the Arduino and DC motor running off the same power source (both off of the same 6V 700mAh pack) but thought it prudent to separate the two. As soon as I did that and connected the power supply, the TB6612FNG went up in smoke as well.

Any suggestions?

2

This was the connection diagram followed:

https://learn.sparkfun.com/tutorials/tb6612fng-hookup-guide?_ga=2.47646695.1946177927.1535542052-1808193875.1534733654

3

Alright, maybe this was common knowledge and I should have known better but the power sequence can cause a short on the TB6612FNG. Guess I'll add a relay to the circuit to make sure it gets powered at the right time.

4

B6612FNG burns out and literally goes up in smoke.

its means that IC cant recieve the current.

5

Its typical for motor drivers to require motor supply first, before logic supply, otherwise internal
paths allow motor current to be pulled from the logic supply. If you derive your Arduino supply
from the motor voltage using a buck converter or regulator this would happen automatically.