Wide-Input Range Dual Mode PWM / Linear Buck Converter with High robustness ESD Protection Circuit

Abstract

Abstract-This paper proposes a high-efficiency, dualmode PWM / linear buck converter with a wide-input range. The proposed converter was designed with a mode selector that can change the operation between PWM / linear mode by sensing a load current. The proposed converter operates in a linear mode during a light load and in PWM mode during a heavy load condition in order to ensure high efficiency. In addition, the mode selector uses a bit counter and a transmission gate designed to protect from a malfunction due to noise or a time-delay. Also, in conditions between -40 °C and 140 °C, the converter has variations in temperature of 0.5mV/°C in the PWM mode and of 0.24 mV/°C in the linear mode. Also, to prevent malfunction and breakdown of the IC due to static electricity, the reliability of IC was improved by embedding a self-produced 8 kVclass(Chip level) ESD protection circuit of a Psubstrate Triggered SCR type with high robustness characteristics.