GaN Totem-Pole PFC Design Guide and Power Loss Modeling

October 11, 2019 by Paul Shepard

Infineon Technologies has published its "CoolGaN™ totem-pole PFC design guide and power loss modeling" design guide to accompany the EVAL_2500W_PFC_GAN_A demo board (pictured above). This design guide is intended for design engineers who want to design a CoolGaN™ Continuous Conduction Mode (CCM) PFC totem-pole converter.

This design guide discusses the PFC stage in high-power applications such as telecom and data center server power supplies.

"CoolGaN totem-pole PFC design guide and power loss modeling" includes:

  • Equations for design and power losses
  • Selection guide for semiconductor devices and passive components
  • Totem-pole PFC controller using ICE3PCS01G
  • 2500 W design example with calculated and experimental results

GaN-based totem-pole PFC proves to be a winning topology in terms of efficiency and power density. This document shows the benefits of GaN-based totem-pole PFC and introduces its analysis and design methodology, including equations for power loss estimation, a selection guide for semiconductor devices and passive components, and a design example with experimental results.

Demo Board

Infineon also offers the EVAL_2500W_PFC_GAN_A demo board showing a high-efficiency PFC stage, which exploits the advantages of Infineon's CoolGaN™ technology to boost the system efficiency above 99 percent for efficiency-critical applications, such as server or telecom rectifiers.

One unique advantage within the enhancement-mode (e-mode) GaN semiconductors is the complete absence of any reverse recovery charge. Therefore this technology enables new topologies in power classes that cannot be addressed by today's HV superjunction (SJ) power semiconductors. Based on these features, the totem-pole PFC topology is the perfect match to exploit the benefits of Infineon's CoolGaN technology.

This demo board shows reliable operation up to 2500W with benchmark efficiency of 99.2 percent. To achieve this, only two discrete 70mΩ CoolGaN switches in combination with two discrete 33mΩ 650V CoolMOS™ C7 Gold switches are required.

All power components are surface mount devices enabling a faster and cheaper assembly process. The control is realized with Infineon's standard ICE3 continuous conduction mode (CCM) control IC. The pwm switching frequency is set to 65kHz.