TC4424EPA output always high

[hippopotamusxd]

As per the attached schematic, I'm using the TC4424EPA to drive MOSFET used as a low-side switch for a DC motor (water pump) with the idea being that the PWM signal from an Arduino will be used to regulate the current flow through the pump.

At first the system worked but it quickly failed and the output of the TC4424EPA remains high even when input is at 0V.

When no signal is connected to the input and the circuit is powered up, the input reads 5V, despite the 10k pulldown resistor on the input.

I've tried replacing the driver, tested the circuit again with a resistive load and it worked as expected, connected the pump again and the it again worked as expected for a little while, but the output again started being high always.

Given how the circuit worked as expected during quick testing with a resistive load instead of the pump and worked as expected at first when the pump was connected I'm not sure what the issue could be.

How can I confirm if the driver is permanently damaged?
If I conclude that the driver is damaged, is there something obviously wrong with the schematic that could be the reason why?

[TomGeorge]

Hi,
Have you tried the other half of the pair in that chip?

Have you checked the MOSFET?
What is part number of the MOSFET?

So with the controller disconnected, pulling the input to 5V or 0V does not move the output from 0V?

Tom....

[jim-p]

@hippopotamusxd

is there something obviously wrong with the schematic that could be the reason why?

Not obvious but one possibility is that the motor may be causing a voltage spike on the 12V power and that is damaging the driver.

Another is that you are exceeding the MOSFET specifications