A synchronous boost regulator with PWM/PFM mode operation

This paper presents a synchronous boost regulator with PWM/PFM mode of operation. It uses synchronous rectification architecture to reduce the conduction loss and improve the efficiency. Furthermore, this paper features a two-level soft-start circuit which prevents the presence of large current generation during system start-up. The simulation results show an efficiency of more than 90% with an input voltage range of 2.7 V~4.2 V and with a load current of 1 mA to 200 mA. This regulator is suitable for ion-battery supply application. It uses TSMC's 0.35 ¿m 2P4M CMOS process.