Charge and discharge control circuit, and charge and discharge control method

摘要

In a charge and discharge control circuit, a mode control part manages a normal mode in which voltages at a power terminal and an overcurrent detection terminal are monitored, a time-shortening mode in which predetermined delay times for detecting an overcharge, an overdischarge, and an overcurrent are shortened, and a protection mode in which a signal to stop a charge current or a discharge current is output when an abnormality is detected in the normal mode. A transition is made from the normal mode to the time-shortening mode when the voltage at the power terminal exceeds a predetermined value, and a transition is made from the time-shortening mode to the protection mode when one of the overcharge, overdischarge, and overcurrent is detected.

主权项

1. A charge and discharge control circuit to control charge and discharge of a secondary battery, comprising:
a power terminal configured to receive power from the secondary battery; an overcurrent detection terminal configured to detect an overcurrent of the secondary battery; an abnormality detection part set with predetermined delay times for detecting an overcharge, an overdischarge, and an overcurrent; and a mode control part configured to control a plurality of modes of operation, wherein the mode control part includes
managing a normal mode in which voltages at the power terminal and the overcurrent detection terminal are monitored by the abnormality detection part, a time-shortening mode in which the predetermined delay times of the abnormality detection part are shortened, and a protection mode in which a signal is output to stop a charge current or a discharge current when an abnormality is detected by the abnormality detection part in the normal mode;making a transition from the normal mode to the time-shortening mode when the voltage at the power terminal monitored by the abnormality detection part exceeds a first predetermined voltage;making a transition from the time-shortening mode to the protection mode when either one of the overdischarge and the overcurrent is detected by the abnormality detection part;wherein the protection mode includes an overcharge protection mode in which the overcharge current is detected by one of the predetermined delay times of the abnormality detection part,wherein the time-shortening mode includes a time-shortening monitor mode in which voltages at the power terminal and the overcurrent detection terminal are monitored by the abnormality detection part, and a time-shortening overcharge voltage detection mode in which the signal to stop the charge current is output when the overcharge is detected by the abnormality detection part, andmaking a transition to the time-shortening overcharge voltage detection mode when the overcharge is detected in the time-shortening monitor mode, making a transition to the time-shortening monitor mode when the overcharge detection of the abnormality detection part ends, and making a transition to the overcharge protection mode when the voltage at the overcurrent detection terminal is lower than a second predetermined voltage in the time-shortening overcharge voltage detection mode.