Controlling BTN7971B by tiny85

Hi everyone,

I am trying to control a high current (around 40amp burst, 15amp constant) motor by mosfet chip BTN7971B with tiny85. By the datasheet this chip can handle max 25khz pwm.

Before I control it by atiny85, I tested the chip as following: pin1: Battery neg- pin3: 5v by LM1085IS-5.0 pin4: nil pin5: nil pin6: nil pin7: Battery pos+ pin8: power output to motor+ motor - connect to battery neg- to activate by giving 5v to pin2

The 1st few trigger that worked perfectly but not sure why I burnt 2 of the chips by this setting after few tried (not work anymore, anyway). I am thinking if pin2 needs pwm signal to handle. Does anyone know what is PRO and CON to use PWM or direct connect the IN pin to 5v? Please advise.

Actually I am making a project to activate brush motor by a button and stop it by a hall effect sensor when the motor rotate to a specific angle both are controlled by tiny85. Please give suggestion.

Does anyone have comment?