900V off-line switcher for industrial and 3-phase power supplies

March 25, 2016 // By Graham Prophet
Power Integrations’ 900-V-rated InnoSwitch-EP family of off-line CV/CC flyback switcher ICs targets power supplies operating from high-voltage DC and three-phase power sources found in industrial, motor-drive, metering and renewable energy applications, and standard mains-voltage applications where continuous operation during line swells and surges is required.

The 900V InnoSwitch-EP ICs offer efficiency of 85% for a dual output 18W design – eliminating heat sinks and enabling highly compact power supply implementations. The company proposes the scenario of industrial-scale power feeds at high-voltage or megawatts scale from which a few milliwatts may be needed to feed a low-voltage microprocessor system, or a few tens of watts for inverter gate drivers. The 900V InnoSwitch-EP devices simplify the design of robust highly reliable power supplies operating from commonly available industrial voltages.

PI’s InnoSwitch-EP IC family employs the company’s safety-rated FluxLink magneto-inductive coupling technology and includes synchronous rectification with accurate secondary-side regulation, resulting in highly efficient, reliable power supply circuits that do not need an optocoupler. The 900V InnoSwitch-EP ICs feature an uprated, integrated 900V power MOSFET which provides a significant operating margin for 450 VAC industrial systems, increasing reliability and operational life. Working continuously with an input voltage of up to 450 VAC, an optional layer of protection - line UV/OV – prevents the IC from switching and protects the circuit up to 650 VAC. This flexibility, says PI, benefits designers of power supplies that suit all worldwide conditions.

900 V InnoSwitch-EP ICs enhance power-supply reliability by reducing BOM count to a minimum level and by eliminating optocouplers which degrade with time. Devices exceed all international energy-efficiency standards such as ENERGY STAR, California Energy Commission and European Union Code of Conduct (CoC), ErP Directive, and the US Department of Energy standards. Devices are UL1577 and TUV (EN60950) safety-approved and EN61000-4-8 (100 A/m) and EN61000-4-9 (1000 A/m) compliant.

900 V InnoSwitch-EP devices are priced at $0.95 (10,000). A reference design, DER-531, is available from; www.power.com/innoswitch-ep