ProMagTech logoProMagTech
Planar Transformer Application Note

1MHz / 3.3kW Half-Bridge LLC 2-in-1 Matrix Planar Transformer

Key finding: At 1MHz and kilowatt power level, the transformer must be reviewed as an integrated electrical, thermal and mechanical structure, not as a standalone turns-ratio part.

This application note summarizes a 2-in-1 matrix planar transformer concept for an 800V HVDC AI-datacenter power stage using a half-bridge LLC topology and GaN-compatible high-frequency operation.

Home / Technical Resources / 1MHz Matrix Planar Transformer
1MHz 3.3kW half-bridge LLC matrix planar transformer application note cover

1. Public Design Scope

The supplied application note identifies the component as a 1MHz / 3.3kW half-bridge LLC resonant transformer for an 800V HVDC AI datacenter DCX stage. The reference operating window shown in the material is 380-420VDC input and a typical 50VDC output.

Topology
Half-bridge LLC resonant transformer with integrated planar resonant inductor Lr review.
Power and frequency
3.3kW rated power and 1MHz switching frequency as stated in the application note.
Structure
2-in-1 matrix planar transformer, ELP58 magnetic core x2 and PLT58/38/4 planar top plate reference.
Thermal path
Top aluminum heat sink with air cooling plus bottom cold plate / conduction thermal path.

2. Why Matrix Planar Structure Matters

The matrix planar layout is used to reduce profile, shorten current paths and make high-frequency winding geometry more repeatable. In this case, the public drawing shows an approximately 80mm x 60mm footprint and 13-14mm total height target. The compact height only has value if AC loss, current sharing, insulation, leakage behavior and heat extraction are reviewed together.

3. Engineering Review Points

For similar high-frequency datacenter power projects, engineers should confirm the LLC operating point, turns ratio, magnetizing inductance, resonant inductance, RMS and peak winding current, copper thickness, PCB layer stack, interwinding capacitance, leakage inductance, creepage and clearance, dielectric test requirement, thermal interface material and cooling boundary.

4. Evidence Boundary

This public page is an application note summary. Final feasibility, loss, temperature rise, insulation margin and production process must be confirmed from the project topology, waveform, PCB stack, magnetic material, cooling condition, mechanical envelope and sample validation record.

Download the PDF Application Note

Download the English application note for the 1MHz / 3.3kW matrix planar transformer design overview.

Download PDF Data

Ask ProMagTech Engineering

Related Engineering Resources

Planar transformer capability

Review ProMagTech planar and flat-wire transformer manufacturing scope.

Planar vs traditional transformer

Compare transformer routes by frequency, thermal path, parasitics and delivery boundary.

LLC frequency knee

Review why higher frequency must be balanced with loss, heat density and process cost.