Infineon launches hybrid power controller for smaller chargers

Infineon Technologies has introduced a new digital controller that combines the simplicity of a flyback converter with the efficiency of a resonant converter. The E-series of the XDP hybrid flyback digital controller utilizes an asymmetrical half-bridge (AHB) topology, catering to a wide range of AC-DC applications. These applications include aftermarket and OEM chargers, adapters, power tools, e-bike chargers, industrial switching power supplies, TV power supplies, and LED drivers.

One notable feature of the E-series is the integration of gate drivers for both gallium nitride (GaN) and silicon switches. This allows for flexibility in selecting power components based on performance and cost considerations. The adaptive power factor correction (PFC) and hybrid-flyback control dynamically adjust the PFC bus voltage to optimize efficiency under various operating conditions, particularly during average and light-load operations.

For fast power-up sequences and consistent efficiency across variable load conditions, a high-voltage 600V start-up cell is incorporated into the design. Additionally, burst-mode control is implemented to minimize standby power consumption, thereby enhancing energy efficiency throughout different operational states.

The XDPS22xx family of controllers addresses common challenges associated with high-density adapters operating at moderate switching frequencies. The hybrid topology employed in these controllers enables zero-voltage switching (ZVS) and zero-current switching (ZCS) over line and load, contributing to superior conversion efficiency. By leveraging magnetization current to achieve ZVS and ZCS, the design optimizes performance while recycling leakage energy.

Unlike traditional topologies, hybrid flyback transformers in the XDPS22xx family do not need to store all the energy, resulting in a more compact charger design. This approach allows for full ZVS operation on the primary side and full ZCS operation on the secondary side, with the leakage energy being efficiently recycled to boost overall efficiency. The duty-cycle adjustment directly impacts the output voltage, offering a solution to the voltage output range limitations often encountered in other topologies.

A reference design showcasing the capabilities of the XPDS2201E HFB controller for a 170W charger has been developed to support wide input designs ranging from 18V to 42V, making it suitable for eBike and Power Tool chargers. With a high peak efficiency of 95% and two control inputs for defining constant current (CC) and constant voltage (CV) regulation loops, this design is well-suited for battery charging applications when combined with a safety switch and charging controller. The inclusion of a voltage doubler ensures adaptability to various residential voltages worldwide.

For more information on the E-series XDP hybrid flyback controller ICs from Infineon, interested parties can refer to the detailed specifications provided by the company.