Efficient 65W USB-C PD Power Design

Pulsiv, a leading technology company based in the UK, has recently introduced a groundbreaking modular 65W USB-C reference design tailored for in-socket chargers. The company is also in the process of developing a more powerful 240W version to cater to a wider range of charging needs.

The 65W USB-C PD reference design by Pulsiv is a testament to the company's commitment to high efficiency and compact size. Unlike traditional external adapters, this design boasts low thermal requirements, making it ideal for integration into sockets by original equipment manufacturers (OEMs).

Tim Moore, the Chief Product Officer at Pulsiv, explained, "We have taken the AC-DC front end of the power supply and pulled it into an end-to-end system. What we really wanted to do with the design was prove the technology works and learn from this." This innovative approach has set a new standard in the industry.

One of the key features of this design is the utilization of 'valley fill' control algorithms developed by Pulsiv and implemented in Osmium, a secure microcontroller. This algorithm enables a half active bridge configuration that enhances efficiency up to 95%, peaking at 96%, despite the challenges at low current levels.

The transformer and inductor components are custom-designed and manufactured by Frenetic in Spain, allowing the design to seamlessly fit into power sockets with a depth of just 25mm. This compact form factor makes it suitable for retrofitting in spaces where efficiency and heat management are critical considerations.

Moreover, the design incorporates gallium nitride (GaN) transistors from Innoscience, operating at 125kHz. While GaN technology presented some challenges during the design process, Pulsiv successfully optimized the system for GaN components. Moore praised Innoscience for their responsive support and high-performance devices.

Notably, the selected GaN parts are not embroiled in the ongoing patent disputes involving other manufacturers. Pulsiv has conducted thorough testing to ensure compatibility with alternative GaN products, such as those from Nexperia, providing flexibility and reliability in the design.