VOLTAGE DETECTING CIRCUIT AND BATTERY DEVICE USING SAME

摘要

A voltage detecting circuit enabling a battery mounted in a device incorporating the voltage detecting circuit to be infallibly used until its use limit and a battery device using the same are provided. The voltage detecting circuit (2) constituting the battery device (1) comprises an input voltage comparing circuit(7) for comparing a first threshold voltage or a second threshold voltage lower than the first one with an input voltage VBAT and controlling the open/close of an output switching element(13) and a threshold voltage forced setting circuit (8) for comparing a third threshold voltage lower than the second threshold voltage with the input voltage VBAT and outputting a pulse to allow the input voltage comparing circuit (7) to forcedly select the second threshold voltage for a predetermined time after the input voltage varies from a low value to a high value and crosses the third threshold voltage. Therefore, when the input voltage VBAT rises from the ground potential, the input voltage comparing circuit (7) compares the second threshold with the input voltage VBAT.