Next-Gen Enhancement-Mode GaN Tech Doubles Performance Over Predecessors

When a new power device improves on its predecessor in some parameter by 50% or even 25%, that’s noteworthy. So, when a vendor maintains its latest generation is twice as good, that’s a real attention-getter.

Such a claim is made by Efficient Power Conversion (EPC) for the company’s EPC2619 enhancement-mode gallium-nitride (eGaN) FET, an 80-V, 4-mΩ device. This is the lead product for a new generation of eGaN devices that have double the power density compared to EPC’s prior-generation products. As a “Gen6” device, it’s a factor-of-two smaller than prior Gen5 devices, as well as faster and therefore more efficient.

The EPC2619 has a tiny 1.5- × 2.5-mm footprint, while maximum R_DS(on) × area of the EPC2619 (an important figure of merit—FoM—but not the only one) is 15 mΩ-mm²—5X smaller than 80-V silicon MOSFETs (Fig. 1).

1. The footprint of the sixth-generation enhancement-mode GaN FETs from Efficient Power Conversion is about half that of fifth-generation devices with comparable ratings.

Target applications include motor drives such as 28- to 48-V conversion for e-bikes, e-scooters, and power tools; high density dc-dc converters; solar optimizers; and synchronous rectification converting 12 V to 20 V for chargers, adapters, and TV power supplies.

Typical R_DS(on) × Q_OSS, a key FoM that’s indicative of power losses in soft-switching applications, is 87 mΩ-nC, which is 2X better than offered by 80-V silicon MOSFETs. This makes the EPC2619 suitable for soft-switching applications, such as the primary rectification full-bridge for LLC-based DCX dc-dc converters.

Typical R_DS(on)× Q_GD, another important FoM that’s related to power losses in hard-switching applications, is 10X better than with 80-V silicon MOSFETs. This enables switching frequencies that are 10X higher than silicon MOSFETs yet without an efficiency penalty, thus producing the highest power density. Thus, the EPC2619 a good fit for high-frequency hard-switching 24- to 48-V applications, such as used in buck, buck-boost, and boost converters (Fig. 2).

2. Performance for a buck-converter configuration using these FETs clearly underscores the improvement between generations.

In addition to the six-page EPC2619 datasheet, EPC offers the EPC90153 Development Board ($200, with a 13-page Quick Start Guide) implementing a half-bridge topology designed for 80-V maximum device voltage and 20-A maximum output current. This 2- × 2-in. (50 × 50 mm) board is designed for optimal switching performance and contains all critical components for effective evaluation (Fig. 3).

3. The EPC90153 Development Board greatly simplifies assessment and performance optimization of the EPC2619 GaN FET.

The EPC2619 is priced at $1.90 each in 2,500-piece volumes. EPC also has an informative seven-page slide presentation “eGaN® Technology Evolution” clarifying the attributes and corresponding benefits of the part and the process technology.