Rechargeable battery protection integrated circuit device with a short circuit detecting voltage change part, rechargeable battery protection module using the rechargeable battery protection integrated circuit device with a short circuit detecting voltage change part, and battery pack with a short circuit detecting voltage change part

• US 8,212,528 B2
• Filed: 10/08/2009
• Issued: 07/03/2012
• Est. Priority Date: 12/04/2008
• Status: Active Grant

• Current Assignee: Mitsumi Electric Co., Ltd. (MinebeaMitsumi Inc.)
• Original Assignee: Mitsumi Electric Co., Ltd. (MinebeaMitsumi Inc.)
• Inventors: Takeda, Takashi
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US12/575,581
• Publication Number:
  US 20100141215A1
• Time in Patent Office: 999 Days
• Field of Search: 320/107, 320/134, 320/136
• US Class Current: 320/134
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A rechargeable battery protection integrated circuit device, includes a short circuit detecting circuit configured to convert a discharge electric current of a rechargeable battery to a voltage value and detect a short circuit state of the rechargeable battery when the converted voltage value is equal to or greater than a designated short circuit detecting voltage; a discharge control terminal configured to output a control signal when the short circuit state is detected by the short circuit detecting circuit, the control signal being configured to stop a discharge of the rechargeable battery; and an overcharge detecting circuit configured to detect an overcharge of the rechargeable battery, wherein the short circuit detecting circuit includes a short circuit detecting voltage change part, the short circuit detecting voltage change part being configured to change the short circuit detecting voltage when the overcharge is detected by the overcharge detecting circuit.

Claims

1. A rechargeable battery protection integrated circuit device, comprising:

a short circuit detecting circuit configured to convert a discharge electric current of a rechargeable battery to a voltage value and detect a short circuit state of the rechargeable battery when the converted voltage value is equal to or greater than a designated short circuit detecting voltage;

a discharge control terminal configured to output a control signal when the short circuit state is detected by the short circuit detecting circuit, the control signal being configured to stop a discharge of the rechargeable battery; and

an overcharge detecting circuit configured to detect an overcharge of the rechargeable battery,

wherein the short circuit detecting circuit includes a short circuit detecting voltage change part, the short circuit detecting voltage change part being configured to change the short circuit detecting voltage when the overcharge is detected by the overcharge detecting circuit.

2. The rechargeable battery protection integrated circuit device as claimed in claim 1,

wherein the short circuit detecting voltage change part is configured to change the short circuit detecting voltage to a voltage value higher than a forward direction voltage of a PN junction of the short circuit detecting voltage change part when the overcharge state is detected by the overcharge detecting circuit.

3. The rechargeable battery protection integrated circuit device as claimed in claim 1,

wherein the short circuit detecting circuit includes a comparator;

and

the short circuit detecting voltage change part includes

a voltage dividing circuit configured to generate the short circuit detecting voltage supplied to one of input terminals of the comparator, and

a switch configured to switch the short circuit detecting voltage supplied from the voltage dividing circuit to the input terminal of the comparator based on detection of the overcharge.

4. The rechargeable battery protection integrated circuit device as claimed in claim 1,

wherein the short circuit detecting circuit includes a CMOS inverter;

and

the short circuit detecting voltage change part includes

an electric current source connected to a high electric potential side of a P channel MOS transistor forming the CMOS inverter, and

a switch configured to switch connection or non-connection of the electric current source based on detection of the overcharge.

5. A rechargeable battery protection module, comprising:

the rechargeable battery protection integrated circuit device as claimed in claim 1; and

a discharge control MOS transistor connected to a discharge control terminal of the rechargeable battery protection integrated circuit device.

6. A battery pack, comprising:

the rechargeable battery protection module as claimed in claim 5; and

a rechargeable battery where the rechargeable battery protection module is connected.