E-bikes, light electric mopeds and electric motorcycles have become the most widespread short-distance transport in China, covering a huge range of scenarios such as daily commuting, food delivery and shared mobility. By the end of 2023, the national two-wheeler EV fleet exceeded 400 million units, far exceeding the 310-million-unit car fleet. The market is enormous, yet supporting charging equipment has long suffered from safety and performance shortcomings, creating an urgent need for industry upgrading.

I. Existing industry charging pain points force solution iteration

As the EV fleet continues to climb, charging fire accidents occur frequently, and various regions have successively issued bans on bringing vehicles and batteries into homes and elevators. Outdoor centralized charging has become the mainstream usage scenario, imposing hard requirements on chargers' dustproof, waterproof and weather-resistant capabilities. Traditional silicon-based chargers can only achieve a high protection rating by enlarging the housing, which greatly compromises portability. At the same time, end users commonly report three major shortcomings of traditional chargers: slow charging, low power-conversion efficiency, and serious heat generation during long operation leading to rapid battery aging. Whether vehicle makers, shared-mobility operators or outdoor charging stations, all urgently need a new-generation charger solution that balances compactness, high efficiency and high safety — third-generation wide-bandgap semiconductors have become the core path to solving these industry pain points.

II. Klinsun Power launches an integrated GaN+SiC two-wheeler charger reference solution

As a domestic R&D manufacturer of third-generation power semiconductor solutions, Klinsun Power is deeply engaged in the application of GaN and SiC devices and the implementation of power solutions. For the electric two-wheeler charging scenario, it has launched a standardized charger solution that optimizes from the device level, solving at once the industry problems of large size, high heat, slow charging and difficult protection of traditional chargers, and adapting to the vehicle-matching needs of multiple power ranges.

1. Core hardware configuration of the 500W solution

Taking the mainstream 500W charger reference design as an example, the whole solution adopts the classic high-efficiency PFC+LLC resonant topology, with all core power devices selected as Klinsun Power's mass-production models:

• PFC boost switch and LLC half-bridge switch: X3G6509B8 GaN HEMT;
• PFC boost rectifier: XD6506F8 SiC Schottky diode.

The bare board measures only 160×50×40mm, with a bare-board power density as high as 1.5625W/cm³; operating frequency is greatly increased — the PFC loop switching frequency is 100KHz and the LLC resonant loop can reach 250KHz. High-frequency characteristics effectively shrink the size of passive components such as transformers, inductors and capacitors, achieving significant weight reduction at the same power and making it easier to build a highly protected portable outdoor charger.

2. Third-generation semiconductors bring all-round performance advantages

GaN and SiC both belong to the third generation of wide-bandgap semiconductors and, compared with traditional silicon devices, have disruptive electrical properties that directly optimize overall charger performance:

1. Higher temperature and voltage tolerance: excellent material breakdown voltage and high-temperature tolerance adapt to complex charging environments such as open-air summer sun and low-temperature outdoors, reducing the risk of high-temperature failure and fire;
2. Extremely low switching loss: higher electron mobility and lower on-resistance support 100kHz-level high-frequency operation, greatly reducing circuit heat and the space taken by heat sinks;
3. Doubled power density: miniaturization of high-frequency passive components shrinks the overall size by more than 30% at the same power, making it easier to build IP-rated waterproof and dustproof housings;
4. Stronger long-term reliability: low leakage current and outstanding thermal and electrochemical stability mean it is less prone to aging under long-term cyclic charging, extending the service life of both charger and battery;
5. Excellent conversion efficiency: low device loss greatly raises full-load conversion efficiency, saving power and reducing operators' long-term electricity costs.

Applied to two-wheeler chargers, this GaN+SiC combination delivers four core improvements at once: faster charging, lower temperature rise, smaller size and higher safety.

III. Prototype measured data: high efficiency, stable waveform, ample EMC margin

1. Full-load-range efficiency curve
Under 90V~260V full mains input, overall efficiency stays above 92% across the 20%~100% load range, with peak full-load efficiency near 97% at 220V mains; light-load loss control is excellent, meeting the Level VI high-efficiency standard and saving more on electricity over long-term use.

2. Oscilloscope waveform test
Under full-load 220Vac input, the GaN drive waveform, LLC resonant current and PFC switch Vds voltage waveform were captured respectively: the waveform edges are clean with excellent spike suppression and small switching oscillation, making EMI interference easier to filter; radiation and conduction interference tests have ample margin, requiring no additional expensive filter components and helping customers control overall BOM cost.

IV. Summary of the solution's deployment value

1. Mature device selection, stable and controllable supply: the core GaN and SiC chips have been verified in numerous Klinsun Power projects, with a self-controllable supply chain and no risk of supply interruption;
2. Compliant with the new national standard: the full set of hardware, waveform and safety tests is complete, fully meeting the new national standard certification requirements for electric two-wheeler chargers, so customers can quickly tool up for mass production based on this solution;
3. Covering multi-scenario needs: supports flexible adjustment across multiple power levels, adapting to diverse scenarios such as household car chargers, outdoor charging piles and shared battery-swap equipment;
4. Comprehensive cost optimization: high-frequency miniaturization reduces the material usage of plastics, heat sinks and passive components, lowers EMC debugging difficulty, shortens mass-production debugging man-hours and dilutes overall production cost;
5. Outdoor safety adaptation: overall heat is greatly reduced and the housing can easily incorporate multiple waterproof and dustproof structures, adapting to outdoor centralized charging in residential communities and reducing high-temperature fire hazards.

Relying on the core GaN+SiC third-generation semiconductor technology, this Klinsun Power electric two-wheeler charger reference design provides vehicle makers and charging equipment manufacturers with a complete power solution that is highly efficient, compact, safe and low-cost, helping the two-wheeler charging industry complete its safety, miniaturization and efficiency upgrade.