I am using a PWM input signal freq - around 500 Hz for driving a 12 V DC motor (less than 2 A). Input (PWM signal) is supplied at Enable "A" and IN 1 and IN 2 are either HI or LO alternately for FORWARD and REVERSE. The IC runs very hot even with heatsinks. Am I doing something wrong. Sometimes it heats up without the motor connected. I have checked all the connections and it is OK. Do you feel the frequency has something to do with it?