2 September 2020
Transphorm releases 4kW analog-controlled bridgeless totem-pole GaN evaluation board
Transphorm Inc of Goleta, near Santa Barbara, CA, USA — which designs and manufactures JEDEC- and AEC-Q101-qualified high-voltage (HV) gallium nitride (GaN) field-effect transistors (FETs) for high-voltage (HV) power conversion applications — has made available its newest evaluation board. Designed for single-phase AC-to-DC power conversion up to 4kW, the TDTTP4000W065AN uses the bridgeless totem-pole power factor correction (PFC) topology with a traditional analog control. This pairing provides fast and easy access to the conversion efficiency made possible by Transphorm’s latest SuperGaN FETs without the need for firmware development required when using digital signal controllers (DSCs).
The TDTTP4000W065AN offers power systems engineers an upgrade in efficiency over standard CCM boost PFC designs that use superjunction MOSFETs.
The evaluation kit is rated at 4kW highline (180-260V) and 2kW lowline (90-120V). The main advantages of the analog totem-pole solution are said to be as follows:
- Maintenance power — power required to support basic functionality such as powering up and supplying chipsets — is a relatively fixed amount in any system. Therefore, as an application’s power level decreases, the maintenance power becomes a larger percentage of the system’s overall power loss. Compared with a DSP solution, Transphorm’s analog board requires lower maintenance power at the onset, increasing overall system efficiency.
- No DSP firmware programming is needed, suitable for standard CCM boost AC-to-DC PFC power stages.
For engineers requiring more design flexibility, Transphorm released the TDTTP4000W066C in April. This DSC-based 4kW AC-to-DC board also uses the bridgeless totem-pole PFC with the company’s SuperGaN FETs. However, it integrates a dsPIC33CK DSC board from Microchip that has been pre-programmed and is backed by dedicated firmware support.
“Transphorm’s analog evaluation board provides an unprecedented opportunity to access our highly efficient GaN in the easiest way possible,” says Philip Zuk, VP of worldwide technical marketing & NA sales. “Much like the preceding digital board, it gives power system engineers a choice that the high-voltage device market was previously lacking,” he adds. “Regardless of the end-application’s targeted value proposition, we have the diverse toolset and the most robust GaN possible.”
The TDTTP4000W065AN employs Transphorm’s SuperGaN Gen IV TP65H035G4WS FETs in the board as the fast-switching leg with low-resistance silicon MOSFETs in the slow-switching leg. The resulting performance is similar to that of its digitally controlled counterpart, the TDTTP4000W066C.
The TP65H035G4WS is a 650V device with a 35mΩ on-resistance in a TO-247 through-hole package with an inherently high thermal dissipation ability. This feature eliminates the need to parallel devices for higher power output, a design method required by competitive surface-mount GaN solutions. Also, as with all other Transphorm GaN devices, the SuperGaN FETs can be driven with a threshold voltage (Vth) of 4V and standard off-the-shelf gate driver operating from 0V to 12V.
The TDTTP4000W065AN evaluation board is currently available through distributors Digi-Key and Mouser.