Power Integrations has added GaN parts to its InnoSwitch3-MX range of ac-dc mains power supply chips, intended for use in TVs, monitors and appliances up to 75W without a heatsink.

This is part of a programme for the company, which is gradually rolling out GaN transistor higher-power versions of its various InnoSwitch3 ICs – see table below – which are system-in-package products that once included only silicon-based power switches.

These are fly-back switcher ICs that, alongside the primary switch, include primary-side controller, secondary-side synchronous rectification controller and an induction-based isolated high-speed communications link.

These chips are intended to work with a secondary side switching chip branded InnoMux – see circuit diagram. The InnoSwitch3-MX receives control instructions from the InnoMux IC, which independently measures the load requirements of each output and directs the switcher IC to deliver the right amount of power to each output to maintaining regulation of current or voltage.

“The InnoMux chipset employs a unique single-stage power architecture that increases overall efficiency to 91% in constant-voltage and constant-current LED backlight driver designs,” according to Power Integrations. “With a breakdown voltage of 750V, the GaN InnoSwitch3-MX parts are also extremely robust and highly-resistant to the line surges and swells commonly-seen in regions with unstable mains voltages.”

The parts are INN3478C, INN3479C and INN3470C.

InnoSwitch3 product table

PowerInt has now filled in the right-hand ‘Parts with GaN transistors’ box.

I am guessing we will see announcement in the InnoSwitch3-CE column at some point….