PORTABLE DEVICE WITH SENSOR FUNCTION

摘要

A small-sized portable device which has a sensor function of detecting and displaying physical information and whose resolution and reproducibility of A/D conversion are ensured by using only one low-cost 1.5V button type silver cell. The portable device is provided with the silver cell used as a low-voltage power source and a boosting power source circuit which boots the low voltage of the silver cell to a high voltage. A sensor driving circuit is driven directly by the low voltage of the cell, and an amplifier circuit and an A/D conversion circuit are driven by the high voltage boosted by the boosting power source circuit. Sensor signals can be processed by using the 1.5V button type silver cell without impairing the existing functions because the boosting power source circuit is provided. The degree of freedom in designing the portable device is increased and the cost of the device is reduced because the device can is light and compact.