HF-Generator for Inductive Heating

This project intended to show the performance and durability of a CoolMOS™ transistor in high frequency clocked bridges using the example of a HF-generator for inductive heating.

Project Targets

Development of a HF generator with an extremely high efficiency for inductive heating


Output power ~ 1 kW

Working frequency 100 - 500 kHz

SMD power transistors

Input voltage 230 Vac

Absolute operational safety under all load conditions


For the generation of an HF-power of 1 kW in the frequency range up to 500 kHz, the generator was realized as a resonant half-bride converter. Each of the both half-bridge switches consist of two parallel connected CoolMOS transistors (type SPB20N60C2 - 190 mOhm, 600 V). Using this approach the generator achieves an efficiency of more than 97%. Due to the low power loss, the power transistors could be mounted in SMD technology and heated by the circuit board. A special control method ensures resonant commutation under all conditions (even transits).

Project Partners

Infineon AG

Project Duration

2000 - 2001

© Fraunhofer IISB