I have some stepper motors driven by DRV8825 modules (running at 24V). When running the steppers it causes voltage spikes on the power rail. This unfortunately killed my TB9051FTG Dual DC motor driver.
The same 24V supply that is going to Vmot on the DRV8825 is also going to Vin on the TB9051FTG.
Googling suggests that the solution is a TVS diode. However, looking at the circuit diagram for the TB9051FTG Dual I think there is already a TVS diode at Vin? Not sure of the symbol.
Will adding a TVS diode (e.g, P6KE30CA-E3/54) be able to protect a TB9051FTG ? I’m afraid to try.
Did you add the required capacitor directly across the Vmot and GND terminals of each motor driver, as described in the product page documentation? I use larger ones, 330 uF to 470 uf, 50V
Consider using separate power supplies for the stepper motors and the TB9051FTG to prevent back EMF and transients from affecting the motor driver. If separate supplies aren’t possible, ensure that the supply lines are well-filtered and that the stepper drivers are properly decoupled.
Yes I did have the capacitor on the DRV8825’s, but nothing on the DC motor driver (although adding one additional capacitor probably wouldn’t make much difference I wouldn’t have thought).
I realised that the diode in the circuit diagram can’t be a TSV diode because the board accepts a range of voltages, so it would be impossible to spec a TSV diode. I think the diode I spotted is a flyback diode.
I’m going to go for it with a TSV diode. I can’t find one with the specs I need ( standoff voltage > 24v, clamping voltage <40v) so I will wire some in series.
Turns out the motor controller was not dead, I had just broken my code. If someone who has successfully destroyed their DC motor controller comes across this thread:
I was going to use a 5KP26A TSV diode to clamp the voltage spike to under 40V.
The diode clamping voltage is actually a little higher than 40V, but this refers to the voltage when the diode is conducting at maximum current, so for spikes without much current it will clamp the voltage to much less.
I was also going to add a flyback diode (running from negative to positive, because stepper motor current spikes will cause ringing (oscillation of the voltage going both +ve and -ve). I would just use a regular 1N4007 diode for this.