Communications Power

1-kW, 80 Plus Titanium, GaN + Silicon Digital AC-DC Power Supply Reference Design

The TIDA-010062 reference design from Texas Instruments is a digitally-controlled, compact 1-kW ac-dc power supply design for server power supply unit (PSU) and telecom rectifier applications combines the use of gallium-nitride FETs in the PFC stage with silicon MOSFETs in the LLC stage. The highly efficient design supports two main power stages, including a front-end continuous conduction mode (CCM) totem-pole bridgeless power factor correction (PFC) stage.

The PFC stage operates from an input voltage range of 100- to 265-Vac and generates a 380-Vdc bus. The second stage is made up of an isolated half bridge LLC stage, which generates a 12-V, 84-A nominal output.

The PFC stage features LMG341x GaN FET with integrated driver to provide enhanced efficiency across a wide load range and meet 80 plus titanium requirements. The design also supports a half-bridge LLC isolated dc-dc stage to achieve a +12-V dc output at 1-kW. Two control cards use C2000™ Piccolo™ microcontrollers to control both power stages.

Features

  • 80 Plus Titanium efficiency, η=>95% @ 20%-100% load
  • CCM GaN based totem pole bridgeless PFC stage with >99% peak efficiency, enabled by LMG341x GaN FET with integrated driver
  • Half-bridge Si MOSFET LLC stage with >98% peak efficiency
  • Fast load transient, Vo change within 300mV @ 2.5A/us slew rate
  • Low iTHD, <10%@10% load, <5% @ 20% load, <2% @ >50% load
  • Power density 41W/in3, 38-mm by 66-mm by 160-mm

The block diagram below shows the high-level block diagram of the design. In this design, two TMS320F280049 C2000™ Piccolo™ control cards are used respectively for the controller of the PFC stage and LLC stage, and an LMG3410 GaN daughter card is used for totem pole half-bridge switching.

TIDA-010062 block diagram (click on image to enlarge)

A silicon MOSFET-based synchronous rectifier, driven by the UCC27714 half-bridge driver, reduces power loss in the low-frequency half bridge at the input. Another silicon MOSFET-based synchronous rectifier used is driven by the UCC21540 isolated half-bridge driver for LLC half-bridge switching. The input current is sensed by a Hall-effect sensor TMCS1100, and the DC link voltage is processed by a variable-gain amplifier stage built using the OPA237 amplifier for better accuracy at low current levels. The output current is sensed by the INA180 current-sense amplifier.

For communication between the primary and secondary control card, Fast Serial Interface (FSI) is sensed by the four-channel digital isolator ISO7742. An onboard auxiliary power supply is implemented using the UCC28911 and provides a 12-V bias for the primary side and a 6-V bias for the secondary side. The TPS560430 is used in both the primary and secondary side for regulated Vcc in control cards and control circuits.

Texas Instruments Incorporated
To Top

Join 50,000+ Power Pros

 

  • Keep pace with relentless innovation
  • Influence the conversation
  • Take your insights to another level

You have Successfully Subscribed!