Power Integrations introduced a breakthrough in flyback topology extending the power range of flyback converters to 440W – well beyond the limits that traditionally required more complex resonant and LLC topologies.
“We’re launching a higher‑power TOPSwitch now because the technology has finally caught up. Advances in gallium nitride and wide bandgap semiconductors allow us to build smaller switches that handle much higher current, so we can push simple flyback designs into power levels that just weren’t practical before,” Andy Smith of Power Integrations told Electronic Specifier.
The new TOPSwitchGaN flyback IC family unites the company’s PowiGaN technology with its TOPSwitch IC architecture, reducing complexity, eliminating heat sinks in many cases, shortening design time, improving manufacturability, and lowering total system cost.
“This is more than a product evolution – it’s a fundamental shift in how engineers can approach power supply design,” said Silvestro Fimiani, Director of Product Marketing at Power Integrations. “For decades, designers have had to move to resonant topologies like LLC as power levels increased. With TOPSwitchGaN, we’re pushing flyback into a power range previously not possible, allowing engineers to achieve high efficiency and performance with a far simpler architecture.”
TOPSwitchGaN ICs provide 92% efficiency across the load range – from 10% to 100% load – and easily beat European Energy-related Products (ErP) regulations at less than 50mW power consumption for standby and off modes. The device does this without the need for synchronous rectification.
PowiGaN switches deliver much lower RDS(ON) than silicon. This results in reduced conduction losses which dramatically increase the power capability of flyback converters. These new devices incorporate 800V PowiGaN switches, which provide excellent surge withstand capabilities and low switching losses, meaning that they can operate at switching frequencies of up to 150kHz to minimise transformer size.
No-load consumption is well below 50mW at 230 VAC including line sense, and up to 210mW of output power is available for 300mW input at 230 VAC to run housekeeping functions when units are in standby mode.
Fimiani continued: “As the first device to combine offline switchers into small packages – and with billions of units sold since 1994 – the TOPSwitch name stands for innovation in power conversion. Engineers rely on TOPSwitch for its efficiency and ease of use, and now those benefits are available for an even wider range of designs. TOPSwitchGaN expands the power range of the flyback architecture to 440W – previously unheard of using a flyback architecture – expanding the use of flybacks into applications previously requiring more complex topologies.”
The new ICs are available in two styles. For ultra-slim designs, low-profile eSOP-12 surface-mount packaging enables 135W (85–265 VAC) to be delivered without a heat sink for applications such as appliances. The vertical orientation of the eSIP-7 package minimises PCB footprint and has a thermal impedance equivalent to a TO-220-packaged part. By mounting a metal heat sink using a simple clip, the extended power range is achieved for applications including power tools, e-bikes, and garage openers. Because TOPSwitchGaN ICs are pin-to-pin compatible with TinySwitch-5 off-line switcher ICs, designers can use the same methodology for applications spanning 10W up to 440W.
“What’s exciting is that engineers can now use essentially the same simple architecture from around 20W all the way up to 400W. That makes it much easier to scale designs across power levels and is a real benefit for markets like power tools, e bikes, appliances and industrial systems,” Smith told me.
Availability & resources
Pricing for TOPSwitchGaN starts at $1.00 for 10,000-unit quantities (TOP7074K-TL). The following reference design materials are available:
- DER-1079 – this kit uses TOP7074K to deliver a 60W, wide-range isolated flyback PSU for appliances
- DER-1019 – this kit details a 356W highline (89V/4A) isolated flyback industrial PSU, based on TOP7078E
- RDK-1018 – this e-bike charger kit is a 168W wide-range isolated flyback design using TOP7075E
For further information, contact a Power Integrations sales representative or one of the company’s authorised worldwide distributors – DigiKey, Newark, Mouser, and RS Components, or visit power.com.
