Diamond Schottky-Diode in a non-isolated buck converter

This work presents the in-circuit operation of a diamond Schottky-diode in a non-isolated buck converter for LED applications at mains voltage. A Schottky-diode on boron doped monocrystalline diamond substrate was assembled in an engineering package. Test structures show breakdown voltages up to 1250 V, current densities up to 470 A/cm², a reverse charge below 1 nC and a decreasing on-resistance with increasing temperature. The packaged device was operated with a peak current of 1 A in a 30W buck converter with stable operation at 125°C. The converter achieves a maximum total efficiency of 87% at 14 W.