i am now actually very frustrated. I already damaged 3 "A4988 Stepper Motor Driver Carrier with Voltage Regulators" and i dont know why this is happening.
When the Driver is damaged the 5V Supply on the board gets very hot, if i dont remove the main supply the main chip explodes in the upper right corner. I think the cause for this is an overvoltage applied on the board which first damages the chip and after that there flows a high current from the 5V supply in the chip and burns it.
My configuration is the exactly how it is mentioned in the description on the web page. The only difference is, that i also use the 5V from the board to power my microcontroller. On the Powersupply Port is an 2000uF Capacitor.
So there are the following components:
Notebook -> programing the arduino (stays connected)
Arduino -> GND and VCC connected to the pololu board
pololu board -> connected to power source (24V)
power source -> i got two types, a lab power supply and a meanwell rail power supply
stepper motor connected
I think it destroys the chip when i disconnect and reconnect the the powercable. I do this for testing my programs etc... the rail power supply seams to be more likely to damage the chip
What could i do to secure the chip? I cant figure out whats the cause for the problem... maybe a voltage peak between the laptop and the powersupply and the 5V powersupply.
I dont have enough chips to destroy to figure out what makes this damage. Could you plz help me how to secure the chip at all costs? Maybe supressingdiodes 28V and 5,8V on the Chip pins?