BOOSTING CIRCUIT AND PORTABLE APPARATUS USING THIS

摘要

As an input voltage to a boosting unit in an arbitrary stage out of multi-stage boosting units, the boosted output of a boosting unit in an earlier stage is input. Therefore, a boosted voltage level per boosting unit can be increased with the number of units reduced. A reference constant current is generated for a boosting unit performing a boosting operation according to a reference constant current when its output voltage does not reach a reference voltage, and the reference constant current is stopped when its output voltage exceeds the reference voltage. Accordingly, an output voltage at a specified level can be output constantly, and a rush current at starting can be limited to a specified current level.