I prototyped an H-bridge servo circuit using the IR2110 Hi/Lo gate driver utilizing the recommended bootstrap method. I PWM the circuit from 31.25nS upto (1,000) to 31.25uS. When I get to about 50% modulation the bootstrap capacitor begins to droop and the under voltage detector disables the driver until the capacitor recharges. I can't fiqure out why this is happening? I expect to at least get to 80% modulation (I know this is the best performance I can expect from this method). I'm using a low leakage schottky diode, and a 10uF tantalum cap. Making this capacitor larger does not seem to improve much. Any ideas?
Mike
Mike
