GaN-based, 15 MHz half-bridge development boards

March 31, 2016 // By Graham Prophet
15 MHz half-bridge development boards use EPC's eGaN FETs and high frequency synchronous bootstrap topology; the boards can be configured as either a buck converter or a ZVS class-D amplifier, demonstrating reduced losses at high frequency using an eGaN FET synchronous bootstrap augmented gate drive.

Efficient Power Conversion’s (EPC) EPC9066, EPC9067, and EPC9068 development boards are configurable as a buck converter or as a ZVS class-D amplifier. These boards provide an easy-to-use way for power systems designers to evaluate the performance of gallium nitride transistors, enabling the designers to get their products into volume production quickly. All three boards feature a zero reverse recovery (QRR) synchronous bootstrap rectifier augmented gate driver to increase efficiency at high frequency operation, up to 15 MHz. The boards can produce a maximum output of 2.7A in the buck and ZVS class-D amplifier configurations. Loss reduction is realised across the entire current range.

 

The EPC9066/67/68 feature 40V, 65V, and 100V-rated eGaN FETs respectively. These boards are 2 x 1.5 in. (appx 5 x 4 cm) and are laid out in a half-bridge configuration. Each board uses the Texas Instruments LM5113 gate driver with supply and bypass capacitors. The gate driver has been configured with a synchronous FET bootstrap circuit featuring the 100V, 2800 mΩ EPC2038 eGaN FET, which eliminates the driver losses induced by the reverse recovery of the internal bootstrap diode. The boards have various probe points and Kelvin measurement points for DC input and output. In addition, the boards provide the capability to install a heat sink for high power operation.

 

The operating load conditions, including configuration, of the development board determine the optimal design load voltage and resistance, resulting in a specific board’s performance. The device parameters for each board are given in the following table:

 

 







Demonstration Board
Part Number

Featured eGaN FET
Part Number

FET
VDS (max)

FET
RDS(on) (max)

Bootstrap FET
(EPC2038)

VDS (max)

RDS(on) (max)

EPC9066

EPC8004

40 V

110 mΩ

100 V

2800 mΩ

EPC9067

EPC8009

65 V

130 mΩ

100 V

2800 mΩ

EPC9068

EPC8010

100 V

160 mΩ

100 V

2800 mΩ

 

 

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