POWER SUPPLY AND PORTABLE APPARATUS

摘要

A stepwise operation command signal rises smoothly through a time constant circuit before inputted as an operation command input voltage to a power supply. Based on the operation command input voltage, operating state or stopping state of the power supply is controlled. When the operation command input voltage exceeds a first predetermined voltage level, a reference voltage is generated by generating a detection signal and an error amplification circuit is operated. When the operation command input voltage reaches a second predetermined voltage level, a level shift voltage for soft start is generated. Consequently, soft start is realized without increasing current consumption and the number of terminals is decreased.