The JoulWatt JW1556 is an asymmetrical half-bridge flyback controller specifically designed for offline flyback converter applications. Encased in a compact QFN 4x4-20 package, it integrates a boost converter with an input voltage range of 2.5-38V and can operate at frequencies up to 1.5MHz, making it ideal for high-power fast-charging applications in the 65W to 300W range. To maximize efficiency, the JW1556 operates in Zero Voltage Switching (ZVS) mode under heavy loads and supports Adaptive ZVS switching, while shifting to Discontinuous Conduction Mode (DCM) at lighter loads. It offers two control outputs for the main power switch and an auxiliary switch, providing flexible power management options.
The JW1556 includes several additional features, such as high-voltage startup, X-cap discharge to reduce standby power, burst mode control for improved energy efficiency at low loads, and adjustable line compensation. Robust fault protection mechanisms, including over-voltage, short circuit, and over-temperature protections, make it a reliable choice for high-efficiency power converters in modern applications.
- Package: QFN 4x4-20
- Input Voltage Range: 2.5V to 38V
- Output Power Range: 65W to 300W (suitable for fast charging applications)
- Maximum Switching Frequency: Up to 1.5MHz
- Operating Modes:
- ZVS (Zero Voltage Switching) with Adaptive ZVS under heavy load
- DCM (Discontinuous Conduction Mode) under light load
- Control Outputs: Main power switch and auxiliary switch
- Additional Features:
- High-voltage startup
- X-cap discharge function for reduced standby power
- Burst mode control
- Adjustable line compensation
- Fault Protections: Over-voltage (VIN OVP, VS OVP), short circuit, over-temperature (OTP), brown-in/brown-out, current sense (CS) open/short
Application Cases:
Teardown of Aohi 140W 2C1A GaN Charger
Teardown of Baseus 100W Retractable Cable Desktop Charger
Teardown of Baseus 130W GaN Charger (2C1A)
Teardown of Baseus 240W GaN Desktop Charger (3C1A+DC)
Teardown of Bull 140W GaN Fast Charging Power Strip (3C1A)
Built-in AHB Architecture, Teardown of Lenovo thinkplus USB-C Mini 100W GaN Charger
Built-in Automotive-Grade SiC MOS, Teardown of Philips 200W Charger
