A high speed and power-efficient level shifter for high voltage buck converter drivers

A driver for high-voltage (HV) single chip synchronous buck converters with a n-channel lateral double diffused MOS (nLDMOS) as power switches and a high speed low power level shifter is presented. Using a short time fast speed pull-down circuit, the level shifter realized high speed with a limited bias current. The circuit is implemented using UMC 0.5-μm 30V LDMOS process, and has been integrated into a buck converter, which requires input voltage up to 25V.