Circuit for detecting remaining battery capacity

Abstract

A disclosed circuit for detecting remaining battery capacity includes: a current detection unit detecting a charge and discharge current of a battery; a remaining capacity measurement unit measuring remaining capacity of the battery by integrating the charge and discharge current at first time intervals when the charge and discharge current detected in the current detection unit is not more than a predetermined value and at second time intervals shorter than the first time intervals when the charge and discharge current exceeds the predetermined value; and an interrupt signal generation unit generating an interrupt signal when the charge and discharge current exceeds a reference value and instructing the remaining capacity measurement unit to measure remaining capacity of the battery.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a block diagram of an embodiment of a circuit for detecting remaining battery capacity according to the present invention;

FIG. 2 is a block diagram of a circuit for generating interrupt signals;

FIG. 3 is an illustration of operations of a circuit for generating interrupt signals;

FIG. 4 is a flowchart of a process of CPU;

FIG. 5 is an illustration of operations of an embodiment of the present invention;

FIG. 6 is a block diagram of an embodiment of a battery pack to which a circuit according to the present invention is applied;

FIG. 7 is a block diagram of an embodiment of a mobile electronic device in which the battery pack in FIG. 6 is used;

FIG. 8 is an illustration of operations of an example of a conventional circuit for detecting remaining battery capacity; and

FIG. 9 is an illustration of operations of another example of a conventional circuit for detecting remaining battery capacity.

Claims

1. A circuit for detecting remaining battery capacity, comprising: a current detection unit detecting a charge and discharge current of a battery;a remaining capacity measurement unit measuring remaining capacity of the battery by integrating the charge and discharge current at first time intervals when the charge and discharge current detected in the current detection unit is not more than a predetermined value and at second time intervals shorter than the first time intervals when the charge and discharge current exceeds the predetermined value; andan interrupt signal generation unit generating an interrupt signal when the charge and discharge current exceeds a reference value and instructing the remaining capacity measurement unit to measure remaining capacity of the battery.

2. The circuit for detecting remaining battery capacity according to claim 1, wherein the current detection unit detects a voltage between both ends of a resistance where the charge and discharge current passes through, andthe interrupt signal generation unit generates the interrupt signal when the voltage between both ends of the resistance where the charge and discharge current passes through exceeds a first reference value and when the voltage between both ends of the resistance where the charge and discharge current passes through is less than a second reference value lower than the first reference value.

3. The circuit for detecting remaining battery capacity according to claim 2, wherein the interrupt signal generation unit includes a window comparator.