Charge/discharge protection circuit for a rechargeable battery

• Main Authors: VONSTAUDT HANS MARTIN, STELLBERGER ACHIM, PANNWITZ AXEL
• Format: Patent
• Language: English; Korean
• Published: 31.07.2002
• Edition: 7
• Subjects: BASIC ELECTRIC ELEMENTS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; GENERATION; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY; SYSTEMS FOR STORING ELECTRIC ENERGY

PURPOSE: A charge/discharge protection circuit for a rechargeable battery is provided to economically realize the protection circuit in standard sub-micro technology having a low break-down voltage, while requiring little real estate on an IC chip. CONSTITUTION: A charge/discharge protection circuit comprises a short-circuit switch(20) coupled in series with a fusible link(2) across the terminals of a rechargeable battery, wherein one end of the fusible link is connected to one of the battery terminals, and the short-circuit switch leads to the guarantied destruction of the fusible link when closed, thereby protecting the rechargeable battery from a dangerous current over-charge, a load current switch having an end coupled to the junction of the fusible link and the short-circuit switch the other end in communication with a first charge/discharge terminal of the protection circuit, wherein the load current switch connects or disconnects the first charge/discharge terminal from the rechargeable battery, a second charge/discharge terminal of the protection circuit coupled to the other end of the battery terminal, and a control logic coupled between the battery terminals and in communication with the first charge/discharge terminal, wherein the control logic protects the battery and the first and the second charge/discharge terminals from over/under-voltage conditions. The control logic opens or closes the load current switch depending on the magnitude of the potential at the first and the second charge/discharge terminals of the protection circuit. The control logic includes an over-voltage detector which closes the short-circuit switch when reaching a predetermined voltage limit which depends on the electric strength of the protection circuit. 본 발명은 가용성 링크(fusible link)에 의해 보호되는 재충전 배터리용 충전/방전 보호 회로에 관한 것이며, 그 재충전 배터리는 배터리 전압, 보호 회로의 충전/방전 단자들 상의 전압 및 충전/방전 전류의 크기에 의존하는 부하 스위치를 개방하거나 닫는 제어 로직을 포함한다. 그 보호 회로는 전기 저항력(electric strength)가 단지 실제의 최대 배터리 전압만을 매칭시키는데 필요하도록 설계되므로, IC 칩 상에 부지(real estate)를 거의 요구하지 않으며, 또한 대부분의 요소들이 집적되도록 한다.