JOULWATT releases JW1556, a high-performance asymmetric half-bridge controller for PD3.1 applications

With the popularity of 100W chargers and mobile power supplies, high-power devices have also begun to use the USB Type-C interface for power supply, forming a complete ecosystem and accelerating the popularity of USB PD. However, for high-performance computing devices, the 100W power provided by the USB PD3.0 protocol is not enough, and the newly launched USB PD3.1 protocol expands the output range of USB PD3.0 and supports 28V, 36V, 48V output , the maximum power reaches 240W, which can meet the power supply requirements of different devices.

USB PD3.1 is a very ambitious standard upgrade, extending the application of USB PD from traditional mobile phones and laptops to portable devices, Internet of Things devices, smart homes, communication and security equipment, automobiles and medical fields. USB PD will become a truly unified power supply standard, which will play an important role in promoting environmental protection of the earth, reducing electronic waste, and interconnecting everything.

JOULWATT  JW1556  comes out

in the traditional charger primary topology, LLC half-bridge resonance is soft switching and has high conversion efficiency. In the PD3.1 application, although the LLC input voltage can be regulated by the PFC pre-stage, the output voltage cannot meet the PD3.1 wide-range output of 5-28V, and a step-down circuit must be additionally matched to achieve a wide-voltage output range.

The AHB asymmetric half-bridge topology not only has the same high conversion efficiency, but also can achieve a wide range of output without an external buck circuit, which is very suitable for PD 3.1 fast charging applications. Facing the increasingly mature AHB controller market, Jiehuat followed the trend and took the lead in launching the asymmetric half-bridge flyback controller JW1556 to fill the gap in the domestic market.

The JW1556 is an asymmetric half-bridge flyback controller in a QFN 4x4-20 package for offline flyback converter applications. Integrated power supply boost converter, the input voltage range is 2.5-38V, the maximum operating frequency is 1.5MHz, and it supports 65-240W fast charging applications.

JW1556 uses ZVS mode under heavy load and supports Adaptive ZVS switch to optimize efficiency. When using DCM mode under light load, it can provide two-way output control of main power switch and auxiliary switch, and support functions such as high-voltage startup, X capacitor discharge, burst mode control, and adjustable line compensation.

The typical application of PD 3.1 power supply composed of JW1556 AHB control chip, JW1571 boost PFC control chip, and JW7726B synchronous rectifier chip is shown in the figure above, and JWHT can provide a one-stop solution for PD 3.1 applications.

Conclusion :

In the applications of 28V, 36V, 48V fixed voltage gears and AVS adjustable voltage gears newly added by the PD 3.1 specification, compared with other topologies such as QR and ACF, the AHB asymmetric half-bridge topology has obvious advantages in terms of efficiency. As the PD 3.1 fast chargingmarket matures, the AHB topology will gradually become popular, replacing the traditional flyback topology on small-volume chargers to achieve higher efficiency and smaller size.

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Date : July 14, 2022