| 摘要 |
<p>PURPOSE: To suitably prevent the over-discharge of a battery in accordance with respective states, even if the operating state of an electric/electronic unit main body-side fluctuates by comparing the output terminal voltage of the battery with a threshold voltage and controlling an opening/closing means in accordance with the compared result. CONSTITUTION: An over-discharge protection circuit 40 is connected to the output terminal of a battery pack in parallel, and a period immediately before the battery becoming an over-discharged (pole change) state is detected by comparing a terminal voltage VBATT with a threshold voltage. Thus, an FET switch SW1 is on/off-controlled. Furthermore, the over-discharge protection circuit 40 discriminates the operating state of a personal computer system by monitoring a sub-power line VCCSB and correspondingly and dynamically adjusts the self-threshold. Consequently, the over-discharge of the battery can be suitably prevented according to the respective states, even if the operation state of the electric/electronic unit main body-side of the personal computer system fluctuates.</p> |
