Smart universal control IC for high loaded factor resonant converters

This paper presents an adaptive universal control IC with error protection functions for high loaded factor (Q>5) resonant converters as in Piezo-Transformer (PT) applications. It has wide frequency tuning range from 25 to 500 kHz. Duty cycle (Dc) tracking and synchronization (SY) are included to ensure Zero Voltage Switching (ZVS) and to extend the input voltage and output load ranges. Automatic burst mode (BM) recognition is implemented by external resistive adjustment. This control IC can switch among Dc tracking, SY and BM by pin connection identification. The IC has been fabricated with Infineon 0.6 ?m B6CA BiCMOS technology. Two demonstration boards for Class E converters with different PTs have been built up to test the controllability and all the functions of the IC.