HYSEMi HY923, Enabling High Power Density in Fast-Charging Designs

Miniaturization and higher power density, managing secondary-side rectification losses and thermal performance has become a critical design bottleneck. LHYSEMi has introduced the HY923 series, an intelligent digital multi-mode synchronous rectifier controller that has become an industry benchmark. Housed in a compact SOT23-6 package, the chip operates as a diode simulator, driving standard external NMOS to replace high-loss Schottky diodes. The HY923 is currently deployed across power segments ranging from 30W to 200W, including mini fast chargers, multi-port wall adapters, desktop charging stations, and smart fast-charging sockets, serving as a core component for reducing secondary-side conduction losses and enhancing overall conversion efficiency.

The core strength of the HYSEMi HY923 lies in its highly flexible topology adaptability and deep digital-layer optimization for high-frequency third-generation semiconductors. The chip utilizes advanced digital control to automatically optimize for various operating modes, including DCM, PFM, CCM, and QR. With an operating voltage range of 3.2V–25V, it is perfectly suited for the wide output requirements of USB PD3.2, PPS, and UFCS, while supporting drain voltage sensing up to 150V without the need for auxiliary windings, greatly simplifying peripheral circuits for high-side or low-side SR applications. Furthermore, to mitigate potential shoot-through risks during high-frequency switching, the HY923 features unique adaptive pre-turn-off technology that minimizes switching losses while improving EMI performance through a flexible turn-off process. The chip also allows for custom volt-second threshold configuration via the INTG pin to eliminate SR MOSFET false triggering caused by transformer parasitic ringing in DCM/QR modes, providing a robust hardware shield for high-power output.

Market teardowns confirm that the HY923 has successfully entered the supply chains of numerous leading global digital brands due to its high-current drive capability and exceptional stability. Notable applications include the Baseus 45W GaN charger, Torras 45W travel series, Lenovo thinkplus 30W 2A1C charger, Anker Nano 45W display charger, and Shilong Fuhua 35W fast-charging socket. Even under extreme high-power, high-heat conditions—such as the Xiaomi 90W 2C1A GaN charger and the Anker 200W six-port flagship desktop station—the HY923 consistently assists the primary controller in reducing secondary-side heat, enabling the successful implementation of high-density stacking designs. Its high adaptability across all power segments makes it a universal semiconductor solution for the industry's shift toward greener, smaller, and more efficient power adapters.