Monolithic GaN half-bridge betters 87% system efficiency, 28V to 1V DC/DC at 14A

December 08, 2014 // By Graham Prophet
The EPC2101 GaN power monolithic half bridge, used in a complete point-of-load (PoL) buck converter, yields system efficiency that approaches 87% at 14A, and over 82% at 30A, when switching at 500 kHz and converting from 28V to 1V while reducing the board area occupied by transistors by 50% when compared to a discrete solution.

EPC2101 is a 60V enhancement-mode monolithic GaN transistor half bridge. By integrating two eGaN power FETs into a single device, interconnect inductances and the interstitial space needed on the PCB are eliminated, resulting in a 50% reduction in board area occupied by the transistors. This increases both efficiency (especially at higher frequencies) and power density, while reducing assembly costs to the end user's power conversion system. The EPC2101 is suited to high frequency DC/DC conversion.

Each device within the EPC2101 half-bridge component has a voltage rating of 60V. The upper FET has a typical RDS(on) of 8.4 mΩ, and the lower FET has a typical RDS(on) of 2 mΩ. The high-side FET is approximately one-fourth the size of the low-side device to optimise efficient DC/DC conversion in buck converters with a high VIN/VOUT ratio. The EPC2101 comes in a chip-scale package for improved switching speed and thermal performance, and is 6.05 x 2.3 mm for increased power density.

The EPC9037 Development Board is 5 x 3.75 cm and contains one EPC2101 integrated half-bridge component using the Texas Instruments LM5113 gate driver, supply and bypass capacitors. The board has been laid out for optimal switching performance and there are various probe points to facilitate simple waveform measurement and efficiency calculation.

The EPC2101 monolithic half-bridge costs $6.92 (1000); the EPC9037 development board is $137.75: both are availab

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