10W charger design for smart mobile devices meets latest specs

April 16, 2015 // By Graham Prophet
Using its InnoSwitch ICs, this reference design from Power Integrations for a 10W CV/CC charger meets DOE-6 and European CoC Version 5, Tier 2 efficiency standards at the end of the cable.

RDK-420 is a reference design kit for a 10W CV/CC USB charger based on the PI’s InnoSwitch-CH family of highly integrated switcher ICs. InnoSwitch ICs combine the primary-side switch together with primary and secondary controllers and feedback circuits into a single, worldwide safety-rated, surface-mount package.

Innoswitch ICs employ accurate secondary-side regulation (SSR), using Power Integrations’ high-speed digital FluxLink technology to communicate direct voltage and current measurements across the safety isolation barrier. This feedback technique permits precise control without the need for an optocoupler, while avoiding the performance compromises inherent in primary-side regulation (PSR), such as limited accuracy and efficiency and poor transient response versus no-load consumption. Other benefits include: ±3% CV, ±5% CC regulation; cable voltage-drop compensation; built-in synchronous rectification driver for high efficiency; <10 mW no-load input power; and accommodation of transformer manufacturing tolerances.

RDK-420 can be purchased from Power Integrations. A complete reference design report (RDR-420) is also available containing the power supply specification, schematic, bill of materials, transformer documentation, printed circuit layout and performance data required to build a 85 VAC – 264 VAC input smart mobile / USB charger with 5V, 2A output, measured in accordance with new European Union Code of Conduct (CoC) Version 5, Tier 2, and US Department of Energy standards (DOE-6), at the end of a USB cable.

Power Integrations; www.power.com/rdk