Low-Power Subcircuits for High-Voltage Designs

This chapter describes the low-power subcircuits developed in this work to enable a reliable and efficient power conversion of the converters described in Chaps. 3 and 4 , even at light-load conditions and measured slew rates as high as 80 V/ns. A clocked high-voltage threshold-detection circuit is presented, which has a detection speed of tens of nanoseconds and more than 1000 times lower sensing losses compared to conventionally used resistive voltage dividers. Reliable low-power gate control of the power switches is achieved with a combination of the common-mode-transient-hardened capacitive level shifter and the high-side gate-pulse generation presented in this chapter. Also, the implemented cascaded gate driver for the power switches is shown. A stable high-side supply is achieved with reverse-recovery optimized bootstrap circuits and the charge pump presented in this chapter. The active snubber circuit described in this chapter reduces ringing at the switching node while keeping additional losses small, thus reducing electromagnetic interference. This chapter also shows the implemented clocked comparator and ring oscillator, which are required to close the control loop with only low additional losses.