They have a robust 750V primary switch using Power Integrations’ PowiGaN technology and a high frequency active clamp flyback controller. They can be used in compact chargers for phones, tablets, and laptops. They have already been used by Anker, which makes mobile charging devices.

There are also primary and secondary controllers, synchronous rectification, and safety-rated feedback, all integrated in a single, compact InSOP-24D package. A steady state switching frequency of up to 140 kHz minimises transformer size to increase power density.  

In contrast with older active clamp flyback approaches, the InnoSwitch4-CZ and ClampZero combination provides up to 95% efficiency and maintains very high efficiency across variations in line voltage, system load and output voltage, claims Power Integrations. This is achieved with variable frequency asymmetrical control of the active clamp with intelligent zero voltage switching, enabling both discontinuous and continuous conduction modes of operation. This enhances design flexibility and maximises efficiency across the entire operating envelope, said the company. The flyback switcher ICs enable CV/CC accuracy, independent of external components, and consume less than 30mW no-load including line-sensing safety and protection features.

The InnoSwitch4-CZ family is a “significant milestone for GaN technology,” commented Balu Balakrishnan, CEO of Power Integrations. “PowiGaN switches, in conjunction with our active clamp solution - ClampZero - enable a highly efficient design and an extremely compact form factor,” he said.  

Steven Yang, CEO at Anker added: "The InnoSwitch4-CZ was a natural choice for Anker's new Nano II series of USB-C chargers. Its outstanding levels of integration and efficiency are key to the Nano II series’ extremely compact design.”

Targeting high efficiency compact USB PD adapters, high-density flyback designs up to 110W and high-efficiency CV/CC power supplies, InnoSwitch4-CZ ICs provide variable output voltage and constant current profiles. Devices are fully protected featuring auto-restart or latching fault response for output over-voltage and under-voltage protection, multiple output under-voltage fault thresholds and latching or hysteretic primary over-temperature protection.