LCC chipset boosts converter efficiency while reducing component count
Delivering over 98 per cent efficiency without the need for a heatsink, the HiperLCS-2 chipset has been unveiled by Power Integrations at APEC 2022. The surface-mount LLC chipset delivers 250W and has no-load consumption of less than 50mW.
The energy-saving HiperLCS-2 chipset can dramatically simplify the design and manufacture of LLC resonant power converters, said Power Integrations. It consists of an isolation device with a high bandwidth LLC controller, synchronous rectification driver and FluxLink isolated control link, together with a separate half-bridge power device using Power Integrations’ 600V FREDFETs with lossless current sensing and high- and low-side drivers. Both devices are housed in low-profile InSOP-24 packages. The result is an integrated, energy-efficient architecture which eliminates heatsinks and reduces component count by up to 40 per cent compared to discrete designs, said the company.
Edward Ong, senior product marketing manager at Power Integrations explained the rationale behind the design: “Resonant converters using separate controllers and discrete MOSFETs can be incredibly bulky and are notoriously difficult to manufacture due to their complexity and high component count. We have applied our advanced FREDFETs and magneto-inductive FluxLink technology to the LLC topology, yielding 98 per cent efficiency and reducing component count . . . while eliminating bulky heatsinks and unreliable optocouplers”. Designers can use the HiperLCS-2 chipset to create compact adapters and open frame power supplies for TVs, monitors with USB PD ports, all-in-one PCs, game consoles and battery chargers for power tools and e-bikes, he advised.
Resonant converters are typically used wherever an application demands a level of efficiency unachievable with single-switch topologies such as flyback converters. The use of the high-speed FluxLink feedback mechanism is claimed to avoid the compromises normally associated with the LLC topology, for designers to quickly and consistently implement designs with high performance, wide operating range and low component count.
Power supply designs based on the new HiperLCS-2 can achieve no-load input power of less than 50mW at 400V DC input and provide a continuously regulated output, to comply with stringent no-load and standby efficiency regulations.
According to Power Integrations, HiperLCS-2 devices operate at high efficiency across the load range with dissipation so low that direct heat transfer through the FR4 PCB is all that is required, eliminating heatsinks in adapter designs up to 220W continuous output with up to 170 per cent peak power capability. All HiperLCS-2 family members feature self-powered start-up and provide the start-up bias for a PFC stage using the company’s HiperPFS ICs. Secondary-side sensing provides less than one per cent regulation accuracy across line and load range and across production variations. Power Integrations added that its FluxLink technology for safety-isolated high-speed digital feedback control provides much faster transient response and far superior long-term reliability compared to optocouplers.
A reference design, DER-672, is available to download and to evaluate HiperLCS-2 ICs.
