Fuel gauge circuit and battery pack

• US 8,658,300 B2
• Filed: 01/12/2010
• Issued: 02/25/2014
• Est. Priority Date: 01/14/2009
• Status: Active Grant

• Current Assignee: Mitsumi Electric Co., Ltd. (Minebea Mitsumi, Inc.)
• Original Assignee: Mitsumi Electric Co., Ltd. (Minebea Mitsumi, Inc.)
• Inventors: Itagaki, Takatoshi, Ikeuchi, Akira, Abe, Makio
• Primary Examiner(s): Kalafut, Stephen J.
• Application Number:
  US13/143,949
• Publication Number:
  US 20110274952A1
• Time in Patent Office: 1,505 Days
• Field of Search: 429/90, 429/92, 429/93
• US Class Current: 429/90
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/13091 Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/19043 being a resistor
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/42 Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells H01M10/60 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A fuel gauge circuit detects a residual quantity of a battery 1 and is disposed on a substrate 20 together with a protection circuit 40 which protects charging/discharging of the battery 1. The fuel gauge circuit includes a voltage monitor terminal T1 disposed on a side facing a positive power-supply terminal 21 of the substrate and connected to each of the positive power-supply terminal 21 and a voltage sensor 31 disposed in the circuit, a voltage through terminal T6 disposed on a side facing the protection circuit, opposite to the side facing the positive power-supply terminal 21, and connected to a voltage monitor terminal T11 of the protection circuit, and a wiring 32 disposed within the circuit to connect the voltage monitor terminal T1 of the fuel gauge circuit to the voltage through terminal T11.

Claims

1. A fuel gauge system for detecting a residual quantity of a battery, comprising:

a substrate having a positive power-supply terminal;

a protection circuit disposed on the substrate, the protection circuit protecting charging and discharging of the battery, and having a voltage monitor terminal; and

a fuel gauge circuit disposed on the substrate, comprising;

a voltage sensor;

a voltage monitor terminal disposed on a side of the fuel gauge circuit, facing the positive power-supply terminal of the substrate, and connected to each of the positive power-supply terminal of the substrate and the voltage sensor disposed in the fuel gauge circuit;

a voltage through terminal disposed on a side of the fuel gauge circuit, facing the protection circuit and being opposite to the side facing the positive power-supply terminal, and connected to the voltage monitor terminal of the protection circuit; and

a wiring disposed within the fuel gauge circuit to connect the voltage monitor terminal of the fuel gauge circuit to the voltage through terminal.

2. The fuel gauge system according to claim 1, further comprising a communication terminal disposed on the side of the fuel gauge circuit, facing the protection circuit, and connected to a communication terminal of the protection circuit to perform bidirectional communication.

3. The fuel gauge system according to claim 2, further comprising a mobile-device communication terminal disposed on the side of the fuel gauge circuit, facing the protection circuit, and connected to a mobile-device communication terminal of the protection circuit to perform bidirectional communication through the protection circuit between a communication part disposed in the fuel gauge circuit and a communication part of a mobile device in which the battery is installed.

4. A battery pack comprising the battery and the substrate, the substrate disposed on a surface of the battery and comprising:

the fuel gauge system of claim 3;

wherein the protection circuit comprises a level shift circuit to perform level shifting of a signal transmitted between the communication part of the fuel gauge circuit and the communication part of the mobile device.