An Input Up to 100-V High Voltage LDO Based a Novel Pre-Regulation and a Simple Clamp Current Circuit

Abstract

With the aim of improving the small input voltage range and complex structure of the current-limiting circuit in the traditional LDO, a wide-range high-voltage input LDO was designed, which uses a pre-regulation principle and a diode current-limiting protection scheme. Based on the DB HiTek 0.18 μm BCD process model for circuit simulation, the simulation results showed that this proposed LDO can stably output 7.6 V under the input voltage range from 13 V to 100 V. In addition, the load regulation rate was 0.0256 mV/mA, and the line regulation rate was 0.035 mV/V. When the load current exceeded 30 mA, the output voltage was prohibited and overcurrent protection was performed. The measurement results showed that the maximum input voltage of the designed chip could reach 140 V. When the load current exceeded 19 mA, the LDO had no output voltage, which indicates that the current limiting circuit can work stably. The circuit designed in this paper has a simple structure but good stability. To date, the LDO has been applied to other DC-DC power supply chips.