Dagu 4 channel motor driver fried
I have fried my 4 channel motor driver and don't know how this can happpen. As you can see in the picture the Dual FET IC U10 for motor 4 is blown away. This happened during a first test of my IOIO-SHR v2 robot. Before connecting the motor driver the program has been tested with an oscilloscope, all Outputs are working as expected. All connections has been double checked. Power supply testet with an voltmeter. Each PWM pin can be controlled from the Android phone with a Slider of my test app. PWM frequency was 1kHz.
Everything works fine I can control the speed of each motor. Both direction pins were LOW during the test, so the motors run only in one direction. After 2minutes playing around I put one slider to 100% PWM. A few seconds later blue smoke comes out of the board. What have I done wrong?
Here is a picture of the schematic I have used. Motor driver 2 and 4 has been used. 5V logic power from the IOIO board. 7.2V motor power from a battery pack. PWM , DIR for each motor has been connected to the IOIO pin 3,4,13,14. The IOIO board is running with 3.3V and so the outputs has only 3.3V, too. Could this be a cause?