Part NumberGS66508B
Spice Models
Step File
Allegro Library
Altium Library
Evaluation BoardsGS665MB-EVB
(Mother board)

(Daughter board)

RDS(on)50 mΩ
QG5.8 nC
Dimensions (mm)7.1 x 8.5 x 0.5
TR QTY3000
MR Size16 mm x 7″
TR Size16 mm x 13″


650V Enhancement Mode GaN Transistor

The GS66508B is an enhancement mode GaN-on-silicon power transistor. The properties of GaN allow for high current, high voltage breakdown and high switching frequency. GaN Systems innovates with industry leading advancements such as patented Island Technology® and GaNPX® packaging. Island Technology® cell layout realizes high-current die and high yield. GaNPX® packaging enables low inductance & low thermal resistance in a small package. The GS66508B is a bottom-side cooled transistor that offers very low junction-to-case thermal resistance for demanding high power applications. These features combine to provide very high efficiency power switching.

  • Ultra-low FOM Island Technology® die
  • Low inductance GaNPX® package
  • Simple gate drive requirements (0 V to 6 V)
  • Transient tolerant gate drive (-20 V / +10 V)
  • Very high switching frequency (> 10 MHz)
  • Fast and controllable fall and rise times
  • Reverse current capability
  • Zero reverse recovery loss
  • Small 7.0 x 8.4 mm2 PCB footprint
  • Source Sense (SS) pin for optimized gate drive
  • RoHS 3 (6+4) compliant


  • AC-DC Converters
  • DC-DC Converters
  • Bridgeless Totem Pole PFC
  • Inverters
  • Energy Storage Systems
  • On Board Battery Chargers
  • Uninterruptible Power Supplies
  • Solar Energy
  • Industrial Motor Drives
  • Appliances
  • Laser Drivers
  • Wireless Power Transfer


650 V Universal Motherboard

This universal motherboard can be used with daughter cards (sold separately) to evaluate the entire GaN Systems 650 V family of GaN E-HEMT products.


  • GS66508B-EVBDB1
  • GS66508T-EVBDB2
  • GS66516T-EVBDB2


650 V GaN E-HEMT Daughter Board

This product requires a motherboard (GS665MB-EVB)

The GS66508B-EVBDB1 daughter board consists of two GaN Systems 650V GaN Enhancement-mode HEMTs (part number GS66508B) and all necessary circuits including half bridge gate drivers, isolated power supplies and optional heatsink to form a functional half bridge power stage. It allows users to easily evaluate the GaN E-HEMT performance in any half bridge-based topology, either with the universal motherboard or the users’ own system design.

  • Serves as a reference design and evaluation tool as well as deployment-ready solution for easy insystem evaluation
  • Vertical mount style with height of 35mm, which fits in majority of 1U design and allows evaluation of GaN
  • E-HEMT in traditional through-hole type power supply board
  • Current shunt position for switching characterization testing
  • Universal form factor and footprint for all products

Created in partnership with Analog Devices, featuring the ADuM4121, a high voltage, isolated gate driver.


300W, 6.78 MHz Class EF2 Power Amplifier For Wireless Power Transfer

The GSWP300W-EVBPA evaluation board is designed to support and expedite the innovation of wireless power transfer systems. The evaluation board uses our GS66508B E-HEMTs in a 300W 6.78MHz class EF2 power amplifier.  With select component changes, the evaluation board can operate up to a power level of 1000W.

Target applications include the wireless charging and powering of drones, robots, power tools, ebikes, AGV and more.

  • Multiple configurations – constant current mode or constant voltage mode
  • Push-pull with EMI filter
  • Single ended mode with/without EMI filter
  • 650V / 30A, 50mΩ GaN E-HEMTs
  • High speed GaN driver
  • Over temperature protection


1.2 kW High Efficiency Bridgeless Totem Pole PFC Evaluation Kit

This evaluation kit demonstrates the performance benefits and design considerations of a high efficiency, high power density 1.2kW Bridgeless Totem Pole PFC (BTP PFC) controlled by advanced digital control methods coupled with GaN Systems’ E-HEMTs.

Technical highlights

  • Continuous Conduction Mode (CCM) BTP PFC
  • Universal AC input (85 V- 264 V)
  • 1.2 kW continuous output power @ 240V
  • 600 W continuous output power @ 85V
  • 385 VDC regulated output voltage with firmware adjustability
  • Adaptive deadtime control
  • Hysteretic current control with cycle by cycle current limiting, fast transient response and inductor current measurement
  • > 99% peak efficiency
  • > 0.99 power factor
  • Low THD (< 3%)


  • Fanless operation
  • Self-powered. External DC supplies are not required
  • Bi-directional power flow, suitable for ESS and OBC systems
  • Low part count and BOM cost due to highly integrated SA4041 controller
  • Easily scaled to 10kW with magnetic and GaN device selection

Created in partnership with Solantro Semiconductor Corp, featuring the SA4041 Digital Power processor


High Power IMS2 Evaluation Platform

This horizontal Insulated Metal Substrate (IMS) evaluation platform can be used to evaluate the electrical and thermal performance benefits of GaNPX® bottom-side cooled E-HEMTs in high power applications.

The optimized thermal and electrical designs provide a excellent reference for implementing a low cost, high performance design.

Features and Benefits

  • Enhanced thermal and mechanical design
  • Ultra low inductance, bottom-cooled GaNPX® package
  • Minimizing parasitic elements of the power and gate drive loops via magnetic flux-cancellation
  • High performance switching with low EMI
  • Scalable and parallelable GaNPX® packaging for applications up to 100 kW
  • Low cost thermal solution for high power applications.

The platform consists of a gate drive motherboard and separate Half Bridge IMS evaluation boards (3kW and 6kW). The motherboard layout is configured to drive 1 or 2 half bridge circuits or 1 full bridge circuit.

IMS2 platform gate drive motherboard

IMS2 half bridge evaluation boards


650 V GaN E-HEMT Daughter Board

Utilize with any ON Semiconductor controller IC eval board

The GS-EVB-HB-66508B-ON1 evaluation board consists of NCP51820 gate drive solution with two GS66508B GaN E-HEMT’s in a fully-functional Half-Bridge. It allows users to easily evaluate GaN in an ultra- small layout with NCP51280 gate driver, for a highly cost-effective solution.

Applications and Benefits:

  • AC-DC Adapters for Mobile, OLED TV, Gaming
  • Datacenter power supplies, PV Inverters/ESS
  • Bridgeless Totem Pole PFC, LLC, ACF, ZVS
  • Highly-integrated Half-Bridge Driver in QFN 4×4 creates ultra-small GaN gate drive layouts
  • 1MHz operation and 200 V/ns CMTI allows high power density GaN-based system designs

Created in partnership with ON Semiconductor, featuring NCP51820, a high voltage Half-Bridge gate driver

25mm x 25mm Layout