Description

This reference design is a Gallium nitride (GaN) based, 3.6kW, single-phase, continuous conduction mode (CCM) totem-pole bridgeless power factor correction (PFC) converter targeting M-CRPS server power supply. This design includes E-meter functionality with 0.5% accuracy using AMCx306 as current sensing device, eliminating the need for external power metering ICs. An alternative low cost current sensing option using TMCS1133 is also provided in this design. The supply is designed to support a maximum input current of 16-ARMS and peak power of 3.6kW. The power stage is followed by a baby boost converter, which helps to greatly reduce the size of the bulk capacitor. This design can work with either LMG3522EVM-042 or LMG3422EVM-043 GaN EVM. LMG3522R030 and LMG3422R030 are TI 30mΩ high-voltage GaN FET with integrated driver and protections, enable high efficiency and high power density. The F28003x C2000™ real-time microcontroller is used for all the advanced controls including re-rush current limit, baby boost operation during AC drop out event, e-metering, and communication between PFC and house-keeping controller. In addition, the F28003x microcontroller has built-in Sigma-Delta filter module to interface with AMC1306 precision current sensing reinforced isolated modulator to achieve industry leading low total harmonic distortion (iTHD) and high measurement accuracy. The PFC operates at a switching frequency of 65kHz and achieves peak efficiency of 98.93%.