Power Integrations — InnoSwitch3-EP Flyback Power Converters

Power Integrations has introduced new versions of its InnoSwitch™3-EP family of integrated flyback power converter ICs which have a 1700 V breakdown voltage rating for use in high-voltage industrial applications. The new parts are also ideal for use in regions which have unstable mains voltages.

The INN3647C and INN3649C products include a silicon carbide (SiC) power MOSFET and offers high conversion efficiency and increased breakdown voltage for the primary switch. In DER-913, an isolated flyback power supply reference design developed by Power Integrations, the INN3647C achieves better than 92% efficiency when supplying a continuous 30 W output at a high ambient temperature of 85 °C. The reference design steps down a 1000 V DC to 24 V.

The INN3647C and INN3649C ICs incorporate a multi-mode quasi-resonant/continuous-conduction mode flyback controller, the high-voltage SiC switch, secondary-side sensing, synchronous rectification driver, safety-rated feedback, and comprehensive protection features into a single IC.

These converters offer all the benefits of secondary-side control with the simplicity of primary-side regulation. They are insensitive to transformer variation and give an extremely fast transient response. The devices provide exceptionally accurate constant-voltage and constant-current regulation across temperature and production.

The converters perform accurate output-current sensing using an external output sense resistor. Excellent noise immunity enables engineers to realize designs which achieve Class A performance according to the EN61000-4 standard.