Charge control circuit and method of adjusting voltage for detecting full charge of secondary battery in same

• US 6,998,817 B2
• Filed: 10/07/2003
• Issued: 02/14/2006
• Est. Priority Date: 10/07/2002
• Status: Active Grant

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Matsuki, Hideo, Ooyagi, Mitsuru
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US10/680,978
• Publication Number:
  US 20040119443A1
• Time in Patent Office: 861 Days
• Field of Search: 320/132, 320/136, 320/149, 320/163
• US Class Current: 320/132
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• CPC Class Codes: H02J 7/007182 in response to battery voltage

Abstract

In a charge control circuit comprising a full charge detection voltage supply device supplying a predetermined full charge detection voltage for detecting a full charge status; and a comparator including a charge status voltage input unit to which is inputted a charge status voltage indicative of the charge status of a secondary battery and a full charge detection voltage input unit to which the full charge detection voltage is inputted, the comparator outputting a result of a comparison between the charge status voltage and the full charge detection voltage, the charge control circuit further comprises an external terminal connected to the full charge detection voltage input unit of the comparator and for adjusting the full charge detection voltage, with an electronic component for adjusting the full charge detection voltage being connectable to the external terminal.

Claims

1. A charge control circuit comprising:

a full charge detection voltage supply device supplying a predetermined full charge detection voltage for detecting a full charge status; and

a comparator including a charge status voltage input unit to which is inputted a charge status voltage indicative of the charge status of a secondary battery, and a full charge detection voltage input unit to which the full charge detection voltage is inputted, the comparator outputting a result of a comparison between the charge status voltage and the full charge detection voltage; and

an external terminal connected to the full charge detection voltage input unit of the comparator, and for adjusting the full charge detection voltage,

wherein an electronic component for adjusting the full charge detection voltage is connectable to the external terminal.

2. A charge control circuit according to claim 1, wherein the electronic component is a resistor.

3. A charge control circuit according to claim 2, wherein one end of the resistor is connected to the external terminal, with the other end of the resistor being connected to the ground.

4. A method of adjusting a voltage detecting a full charge of a secondary battery in a charge control circuit, the charge control unit comprising a comparator including a charge status voltage input unit to which is inputted a charge status voltage indicative of the charge status of the secondary battery, and a full charge detection voltage input unit to which is inputted a predetermined full charge detection voltage for detecting the full charge status, the comparator outputting a result of a comparison between the charge status voltage and the full charge detection voltage, wherein

an external terminal for adjusting the full charge detection voltage is connected to the full charge detection voltage input unit of the comparator, the adjusting method comprising:

adjusting the full charge detection voltage by connecting an electronic component to the external terminal.

5. A method of adjusting a voltage detecting a full charge of a secondary battery according to claim 4, wherein the electronic component is a resistor.

6. A method of adjusting a voltage detecting a full charge of a secondary battery according to claim 5, wherein one end of the resistor is connected to the external terminal, with the other end of the resistor being connected to the ground.

7. A method of adjusting a voltage detecting a full charge of a secondary battery according to claim 5, wherein

a reference voltage terminal is connected to a reference voltage source for generating the full charge detection voltage, and wherein

one end of the resistor is connected to the external terminal, with the other end of the resistor being connected to the reference voltage terminal.

8. A method of adjusting a voltage detecting a full charge of a secondary battery according to claim 5, wherein

the resistor includes a first resistor element and a second resistor element, with a reference voltage terminal being connected to a reference voltage source for generating the full charge detection voltage,

one end of the first resistor element being connected to the external terminal with the other end of the first resistor element connected to the ground, and one end of the second resistor element being connected to the external terminal with the other end of the second resistor element connected to the reference voltage terminal.