ZVS flyback ICs shrink adapter size

Power Integrations has launched its InnoSwitch4-Pro family of digitally controllable, off-line CV/CC zero voltage switching (ZVS) flyback ICs that claim to “substantially” reduce the size of power adapters, delivering over 95% efficiency. Combining programmability, high efficiency, and a small form factor, the flyback switchers, capable of delivering up to 220 W, combine a 750-V PowiGaN primary switch, controller, FluxLink reinforced isolation feedback link for secondary-side control, an I2C interface, active clamp drive, and synchronous rectification in a compact InSOP-28 package.

(Source: Power Integrations)

Thanks to the integration of the company’s PowiGaN gallium-nitride primary switch and steady-state switching frequency of up to 140 kHz, the integrated devices reduce the component count and PCB area required for ultra-compact adapters for cellphone, notebook, tablet, and multi-port accessories. The high efficiency enables the elimination of heat sinks, spreaders, and potting materials typically required for thermal management, according to the company.

“ZVS, combined with our PowiGaN technology, virtually eliminates switching losses,” said Aditya Kulkarni, product marketing manager at Power Integrations, in a statement. The new flyback switchers also interface with the company’s Integrations’ ClampZero family of active clamp ICs to achieve ZVS in both continuous conduction mode (CCM) and discontinuous conduction mode (DCM), he stated.

InnoSwitch4-Pro flyback switcher ICs also claim “exceptional” CV/CC accuracy, independent of external components, and consume less than 30 mW no-load while offering line-sensing and protection features, said the company. Protection features include auto-restart or latching fault response for output overvoltage and undervoltage protection, multiple output undervoltage fault thresholds, latching or hysteretic primary over-temperature protection, and output bus switch short-circuit protection.

The adapter size can be further reduced by using the company’s MinE-CAP ICs in combination with InnoSwitch4-Pro and ClampZero ICs, said the company. MinE-CAP devices are also based on the PowiGaN technology and can reduce input capacitance size by approximately 40 percent. Together, they enable ultra-compact and slim form factors required by OEM accessory and aftermarket USB PD and Universal Fast Charging Specification (UFCS) adapters, said the company.

The InnoSwitch4-Pro flyback ICs are priced at $1.85 in 10,000-unit quantities. More information is available via Power Integrations or one of the company’s authorized worldwide distributors: Digi-Key, Farnell, Mouser, and RS Components. Two reference designs, DER-960 (100 W) and RDK-942 (65 W), are available, which the company is showcasing at electronica, Nov. 15-18, Munich, Germany, at Hall C2, Booth 141.