GaN Talk Blog

This article orginally appeared on EE Times.

The power MOSFET market is large and well established, and is expected to reach a value of around $14 billion by 2027. It is generally divided into three voltage segments: below 40 V, 40–200 V, and above 600 V. The segment below 200 V accounts for roughly 75% of the total market. It is in this segment that most of the target applications of Efficient Power Conversion (EPC) are concentrated, including AI servers, 48-V power converters, robotics, and autonomous machines. This makes it a crucial battleground for the adoption of GaN technology. By focusing on higher efficiency, increased power density, and simpler system design, GaN technology is increasingly positioning itself as a viable replacement for silicon in modern power conversion systems.

48 volts is increasingly being adopted as the new standard for computing data centers and consumer electronics such as laptops. The new USB PD3.1 standard is also making inroads into laptops driven in part by the increase in USB voltage to 48 V that increases the total power delivery up to 240 W given a current limit of 5 A for the connectors and cables. Compatible power supplies using the new USB PD standard also face increasing pressure to yield a small form factor solution driving the need for high power-density. The fast-switching speed and low R_DSon of GaN FETs address this challenge in multiple circuits that make up the power supply.

Brick DC-DC converters are widely used in data center, telecommunication and automotive applications, converting a nominal 48 V bus to (or from) a nominal 12 V bus. Advances in GaN integrated circuit (IC) technology have enabled the integration of the half bridge and gate drivers, resulting in a single chip solution that simplifies layout, minimizes area, and reduces cost.

This application note discusses the design of a digitally controlled bi-directional 1/16th brick converter using the integrated GaN power stage for 48 V-to-12 V application, with up to 300 W output power, and peak efficiency of 95%.

The standard dimension of the 1/16th brick converter is 33 x 22.9 mm (1.3 x 0.9 inch). The height limit for this design is set to 10 mm (0.4 inch).

This post was originally published by Bill Kleyman on November 5, 2018 on the Data Center Frontier  web site. Learn more about eGaN technology and EPC GaN solutions for the Data Center.

The data center is an ever-changing entity and part of our technological landscape. But sometimes the biggest changes in the colocation industry happen at the core of what makes a data center tick, and may not be visible at first glance. In this instance, we’re talking about data center power, and the potential of creative solutions on the market, such as using Gallium nitride (GaN) in power conversion equipment.

Motivation

eGaN FETs are capable of switching much faster than Si MOSFETs, requiring more careful consideration of PCB layout design to minimize parasitic inductances. Parasitic inductances cause higher overshoot voltages and slower switching transitions. This application note reviews the key steps to design an optimal power stage layout with eGaN FETs, to avoid these unwanted effects and maximize the converter performance.

Impact of parasitic inductance on switching behavior

As shown in figure 1, three parasitic inductances can limit switching performance 1) power loop inductance (L_loop), 2) gate loop inductance (L_g), and 3) common-source inductance (L_s). The chip-scale package of eGaN FETs eliminates any significant inductance within the transistor itself, leaving the printed circuit board (PCB) as the main contributor. Each parasitic inductance is a consequence of the total area encompassed by the dynamic current path and its return loop. (See WP009: Impact of Parasitics on Performance).

This post was originally published May 26, 2017 on the PowerPulse.net web site . Learn more about eGaN technology and EPC GaN solutions for 48 V to Point-of-Load.

During last week’s PCIM Europe event in Nuremberg, Germany, direct 48V-to-1V power conversion architectures were a significant topic, mostly outside of the exhibit floor. Vicor was quietly showing its latest generation of 48V direct-to-chip power components. Ericsson Power Modules and Efficient Power Conversion were holding invitation-only meetings where future designs of 48V direct to load power conversion architectures were the focus of the discussions. By the end of 2017, several vendors are expected to be offering dc-dc converters delivering 48V-to-1V direct conversion.