Fast Charger

Following European Commission’s new regulation announced on Oct.4, 2022, all mobile phones, tablets and cameras sold in the EU will have to be equipped with a USB Type-C charging port by the end of 2024. On the other hand, the latest USB-PD (power delivery) Extended Power Range (EPR) standard enables higher power levels of up to 240 W. This leads to a proliferation of universal AC-DC adapter products for powering/charging a wide range of devices, from smartphones, tablets, to power tools, and even e-bikes. Meanwhile, although the stringent energy efficiency standard CoC Tier 2 did not become law in Europe as expected, the U.S. Department of Energy’s (DoE) new "Energy Conservations Standards," also called the Level VI specification, together with the market trend of slim and compact design, keep demanding higher efficiency and higher power density power conversion. This, in turn, calls for highly efficient converter topologies and power semiconductors.

Flyback and LLC are the commonly used topologies in the AC-DC power conversion in the fast chargers. Flyback topology is frequently used in designs with output power less than 100W while LLC topology are typically found in higher power fast chargers which mandates the use of active power factor correction (PFC). Due to the relatively lower BOM cost than the LLC topology, high efficiency flyback topologies such as active clamp flyback (ACF) and hybrid flyback topology (HFB) are adopted by more and more medium-power charger designs.

JJM offers a rich portfolio of discrete semiconductor components for high efficiency fast chargers. These include anti-surge MOV and TVS at the AC input end, FRD (fast recovery diodes) that suppress the voltage spikes caused by the transformer leakage, high voltage MOSFETs which are used in the primary side performing PFC as well as DC/DC conversion, MV/LV MOSFETs for synchronous rectification and power-switching at the USB Type-A/C ports, ESD protection for the USB PD protocol IC, Opto-coupler etc.