A wide duty cycle range wide band high frequency isolated gate driver for power converters

There are many gate driver circuits in the literature both with and without galvanic isolation. Almost all existing methods have limitations either in duty cycle and/or switching frequency. Further, most of the opto-isolated drives require multiple isolated power supplies. This paper presents a novel isolated gate driver based on dual forward converter topology that addresses the above issues. In the proposed gate drive, two forward converter transformers are paralleled at the secondary side achieving 0–100% duty cycle together with galvanic isolation and only with a single power supply. The gate driver switching devices and magnetics are designed for high frequencies independent of the main PWM frequency. At high frequencies, problems of resonance due to parasitics become significant. This paper also discusses this problem and proposes a novel solution to mitigate it. This circuit can be used for any application irrespective of switching frequency thus making it a wide band generalized gate driver. The proposed circuit is analyzed and verified experimentally.