Single-stage flyback controller for battery charging applications

Battery-powered appliances, one of the industry’s fastest-growing segments, require energy-efficient, robust, and cost-effective battery charging. For this reason, Infineon Technologies AG extends its offering of AC-DC controller ICs by introducing the ICC80QSG single-stage PWM controller for flyback topologies.

The IC is tailored for battery charger applications offering scalable power designs of up to 130 W – when optimised using CoolMOS P7 Superjunction (SJ) MOSFETs. It is also suitable for adapter, printer, PC, TV, monitor, set-top box, and audio amplifier applications.

The ICC80QSG battery charging IC offers a quasi-resonant mode, switching in valley n (QRMn). Its QRM operation comes with continuous conduction mode (CCM) prevention and valley switching discontinuous conduction mode (DCM) in mid to light load. By pairing ICC80QSG with CoolMOS P7 MOSFET devices, high efficiency and low electromagnetic interference (EMI) can be achieved to enable savings on the overall BOM: fewer heatsinks and coils may be needed in flyback designs.

In addition, the integrated burst mode function for very light loads allows designs with very low power consumption during standby mode. Additionally, the ICC80QSG features a reduced gate driver output voltage during burst mode, making it ideally suited for very low standby requirements under light load or no load conditions with a remarkable standby performance over the whole operating range.

The ICC80QSG implements a secondary-side regulation (SSR) method, which is ideal for current control during battery charging. For higher design flexibility, it accommodates adjustable on-time mapping at the valley changing position for the desired maximum operating switching frequency, as well as adjustable maximum on-time that limits input power and current, allowing safe operation under low line conditions.

The IC features an externally configurable hysteresis of brown-in and brown-out to protect the primary MOSFET by ensuring it does not get overheated even with fewer heatsinks during input undervoltage with tight brown-in/brown-out hysteresis. Together with a comprehensive set of protection features, the IC helps realise easy, safe and robust AC-DC battery charger designs for many applications.