IP Library Granted Patent US 6,940,256
Granted Patent B2
US 6,940,256 · App. 10/670,816 · Granted Sep 6, 2005

Battery state monitoring circuit and battery device

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Quick Facts
Patent No.
US 6,940,256
App. No.
10/670,816
Granted
Sep 6, 2005
Kind
B2
Abstract

To realize a battery state monitoring circuit in which detection is reliably made even if a continuous noise is entered, and to provide a battery device which has a long life and is safe. In the battery state monitoring circuit, the detecting circuit outputs a signal for controlling a switch circuit in accordance with a state of the secondary battery with respect to one of a specified voltage value and a specified current value. The signal includes one of: a detection signal for starting one of charge protection and discharge protection of the secondary battery; and a release signal for releasing the one of the charge protection and the discharge protection of the secondary battery. A switching rate from the release signal to the detection signal is higher than a switching rate from the detection signal to the release signal.

Claims (42)

1. A battery state monitoring circuit, comprising:

a switch circuit that adjusts a current of a secondary battery which is chargeable and dischargeable; and

a detecting circuit that monitors at least one of a voltage and the current of the secondary battery and outputs a signal for controlling the switch circuit, wherein:

the detecting circuit outputs the signal for controlling the switch circuit in accordance with a state of the secondary battery with respect to one of a specified voltage value and a specified current value;

the signal is one of: a detection signal for starting one of charge protection and discharge protection of the secondary battery; and a release signal for releasing the one of the charge protection and the discharge protection of the secondary battery; and

a switching rate from the release signal to the detection signal is higher than a switching rate from the detection signal to the release signal.

2. A battery state monitoring circuit according to claim 1 , wherein:

the detecting circuit is an over-charge detecting circuit that can detect an upper limit voltage to which the secondary battery is charged; and

the over-charge detecting circuit outputs:

the detection signal for the charge protection of the secondary battery by the switch circuit when the voltage of the secondary battery is larger than the upper limit voltage to which the secondary battery is charged; and

the release signal for releasing the charge protection of the secondary battery by the switch circuit when the voltage of the secondary battery is equal to or smaller than the upper limit voltage to which the secondary battery is charged.

3. A battery state monitoring circuit according to claim 1 , wherein:

the detecting circuit is an over-discharge detecting circuit that can detect a lower limit voltage to which the secondary battery is discharged; and

the-over-discharge detecting circuit outputs:

the detection signal for the discharge protection of the secondary battery by the switch circuit when the voltage of the secondary battery is equal to or smaller than the lower limit voltage to which the secondary battery is discharged; and

the release signal for releasing the discharge protection of the secondary battery by the switch circuit when the voltage of the secondary battery is larger than the lower limit voltage to which the secondary battery is discharged.

4. A battery state monitoring circuit according to claim 1 , wherein:

the detecting circuit is an over-current detecting circuit that can detect an upper limit current to which the secondary battery is discharged; and

the over-discharge detecting circuit outputs:

the detection signal for the discharge protection of the secondary battery by the switch circuit when the current of the secondary battery is larger than the upper limit current to which the secondary battery is current to which the secondary battery is discharged; and

the release signal for releasing the discharge protection of the secondary battery by the switch circuit when the current of the secondary battery is equal to or smaller than the upper limit current to which the secondary battery is charged.

5. A battery device, comprising:

a switch circuit that adjusts a current of a secondary battery which is chargeable and dischargeable; and

a detecting circuit that monitors at least one of a voltage and the current of the secondary battery and outputs a signal for controlling the switch circuit, wherein:

the detecting circuit outputs the signal for controlling the switch circuit in accordance with a state of the secondary battery with respect to one of a specified voltage value and a specified current value;

the signal is one of: a detection signal for starting one of charge protection and discharge protection of the secondary battery; and a release signal for releasing the one of the charge protection and the discharge protection of the secondary battery; and

a switching rate from the release signal to the detection signal is higher than a switching rate from the detection signal to the release signal.

6. A battery device according to claim 5 , wherein:

the detecting circuit is an over-charge detecting circuit that can detect an upper limit voltage to which the secondary battery is charged; and

the over-charge detecting circuit outputs:

the detection signal for the charge protection of the secondary battery by the switch circuit when the voltage of the secondary battery is larger than the upper limit voltage to which the secondary battery is charged; and

the release signal for releasing the charge protection of the secondary battery by the switch circuit when the voltage of the secondary battery is equal to or smaller than the upper limit voltage to which the secondary battery is charged.

7. A battery device according to claim 5 , wherein:

the detecting circuit is an over-discharge detecting circuit that can detect a lower limit voltage to which the secondary battery is discharged; and

the over-discharge detecting circuit outputs:

the detection signal for the discharge protection of the secondary battery by the switch circuit when the voltage of the secondary battery is equal to or smaller than the lower limit voltage to which the secondary battery is discharged; and

the release signal for releasing the discharge protection of the secondary battery by the switch circuit when the voltage of the secondary battery is larger than the lower limit voltage to which the secondary battery is discharged.

8. A battery device according to claim 5 , wherein:

the detecting circuit is an over-current detecting circuit that can detect an upper limit current to which the secondary battery is discharged; and

the over-discharge detecting circuit outputs:

the detection signal for the discharge protection of the secondary battery by the switch circuit when the current of the secondary battery is larger than the upper limit current to which the secondary battery is current to which the secondary battery is discharged; and

the release signal for releasing the discharge protection of the secondary battery by the switch circuit when the current of the secondary battery is equal to or smaller than the upper limit current to which the secondary battery is charged.

Assignments (3)
CHANGE OF NAME Recorded Mar 12, 2018
From: SII SEMICONDUCTOR CORPORATION
To: ABLIC INC.
Reel/Frame 045567/0927 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 10, 2016
From: SEIKO INSTRUMENTS INC.
To: SII SEMICONDUCTOR CORPORATION
Reel/Frame 038058/0892 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 1, 2005
From: SAKURAI, ATSUSHI
To: SEIKO INSTRUMENTS INC.
Reel/Frame 016821/0312 →