VOLTAGE MONITOR SEMICONDUCTOR DEVICE, BATTERY PACK, AND ELECTRONIC DEVICE EMPLOYING BATTERY PACK

• US 20120229091A1
• Filed: 03/08/2012
• Published: 09/13/2012
• Est. Priority Date: 03/11/2011
• Status: Active Grant

• Current Assignee: RICOH Electronic Devices Co., Ltd. (Nisshinbo Holdings Incorporated)
• Original Assignee: Ricoh Company Limited
• Inventors: KANZAKI, Daisuke
• Granted Patent: US 9,103,893 B2
• Time in Patent Office: Days
• US Class Current: 320/112
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]

Abstract

A voltage monitor semiconductor device to monitor voltages of multiple rechargeable devices to output a detection result signal to indicate overcharge, over-discharge, or excess-current, the voltage monitor semiconductor device including multiple voltage input terminals, corresponding to the multiple rechargeable devices, to monitor the voltages of the corresponding rechargeable devices as monitor voltages; and a test signal generation circuit to generate a first test signal that inverts when at least one of the monitor voltages falls below a predetermined first threshold voltage that is not used normally as an abnormal state.

Claims

1. A voltage monitor semiconductor device to monitor voltages of multiple rechargeable devices and output a detection result signal to indicate abnormal state,

the voltage monitor semiconductor device comprising:

multiple voltage input terminals, corresponding to the multiple rechargeable devices, to monitor the voltages of the corresponding rechargeable devices as monitor voltages; and

a test signal generation circuit to generate a first test signal when at least one of the monitor voltages falls below a predetermined first threshold voltage that is not used normally.

2. The voltage monitor semiconductor device according to claim 1, further comprising:

a delay circuit to delay the detection result signal at a preset delay time, having a reduction element to shorten the delay time generated in the delay circuit,

wherein, when the monitor voltage of at least one of the rechargeable device becomes lower than the first threshold voltage and the first test signal is generated, a delay time for detecting the abnormal state in the rechargeable devices except the at least one of the rechargeable device is shortened to a first shortened time.

3. The voltage monitor semiconductor device according to claim 1, wherein the first threshold voltage is set to either 0 V or equal to or less than a lower limit discharging voltage.

4. The voltage monitor semiconductor device according to claim 1, wherein the test signal generation circuit generates a second test signal when at least one of the monitor voltages falls below a predetermined second threshold voltage lower than the first threshold voltage that is not used normally.

5. The voltage monitor semiconductor device according to claim 4, further comprising:

a delay circuit to delay the detection result signal at a preset delay time, having a reduction element to shorten the delay time generated in the delay circuit,

wherein, when the monitor voltage of at least one of the rechargeable device becomes lower than the first threshold voltage and the first test signal is generated, a delay time for detecting abnormal state in the rechargeable devices except the at least one of the rechargeable device is shortened to a first shortened time;

wherein, when the monitor voltage of at least one of the rechargeable device becomes lower than the second threshold voltage and the second test signal is generated, a delay time for detecting the abnormal state in the rechargeable devices except the at least one of the rechargeable device is shortened to a second shortened time that is different from the first shortened time.

6. The voltage monitor semiconductor device according to claim 4, wherein the second threshold voltage is set to a predetermined negative value that is lower than the first threshold voltage or the second threshold voltage is set to be lower than the lower limit discharging voltage that is lower than the first threshold voltage.

7. The voltage monitor semiconductor device according to claim 1, wherein the abnormal state comprises an over-charge state.

8. The voltage monitor semiconductor device according to claim 1, wherein the abnormal state comprises an over-discharge state.

9. The voltage monitor semiconductor device according to claim 1, wherein the abnormal state comprises an excess-current state.

19. The battery pack employing multiple rechargeable devices and the voltage monitor semiconductor device of claim 1.

10. A voltage monitor semiconductor device to monitor voltages of multiple rechargeable devices to output a detection result signal to indicate abnormal state,

the voltage monitor semiconductor device comprising:

multiple voltage input terminals, corresponding to the multiple rechargeable devices, to monitor the voltages of the corresponding rechargeable devices as monitor voltages; and

a test signal generation circuit to generate a first test signal when at least one of the monitor voltages exceeds a predetermined third threshold voltage that is not used normally.

11. The voltage monitor semiconductor device according to claim 10, further comprising:

a delay circuit to delay the detection result signal at a preset delay time, having a reduction element to shorten the delay time generated in the delay circuit,

wherein, when the monitor voltage of at least one of the rechargeable device becomes higher than the third threshold voltage, a delay time for detecting abnormal state in the rechargeable devices except the at least one of the rechargeable device is shortened to a first shortened time.

12. The voltage monitor semiconductor device according to claim 10, wherein the third threshold voltage is set to either a positive voltage or equal to or higher than an upper limit charging voltage.

13. The voltage monitor semiconductor device according to claim 10, wherein the test signal generation circuit generates a second test signal when at least one of the monitor voltages exceeds a predetermined fourth threshold voltage that is higher than the third threshold voltage.

14. The voltage monitor semiconductor device according to claim 13, further comprising:

a delay circuit to delay the detection result signal at a preset delay time, having a reduction element to shorten the delay time generated in the delay circuit,

wherein, when the monitor voltage of at least one of the rechargeable device becomes higher than the third threshold voltage, a delay time for detecting abnormal state in the rechargeable devices except the at least one of the rechargeable device is shortened to a first shortened time;

wherein, when the monitor voltage of at least one of the rechargeable device becomes higher than the fourth threshold voltage, a delay time for detecting the abnormal state in the rechargeable devices except the at least one of the rechargeable device is shortened to a second shortened time that is different from the first shortened time.

15. The voltage monitor semiconductor device according to claim 13, wherein the fourth threshold voltage is set to a predetermined positive value that is higher than the third threshold voltage or the fourth threshold voltage is set higher than the higher limit charging voltage that is higher than the third threshold voltage.

16. The voltage monitor semiconductor device according to claim 10, wherein the abnormal state comprises an over-charge state.

17. The voltage monitor semiconductor device according to claim 10, wherein the abnormal state comprises an over-discharge state.

18. The voltage monitor semiconductor device according to claim 10, wherein the abnormal state comprises an excess-current state.

20. An electronic device comprising:

a load or a charger and

a battery pack comprising;

multiple rechargeable devices; and

a voltage monitor semiconductor device to monitor voltages of the multiple rechargeable devices to output a detection result signal to indicate overcharge, over-discharge, or excess-current,

the voltage monitor semiconductor device comprising;

multiple voltage input terminals, corresponding to the multiple rechargeable devices, to monitor the voltages of the corresponding rechargeable devices as monitor voltages; and

a test signal generation circuit to generate a first test signal that inverts when at least one of the monitor voltages falls below a predetermined first threshold voltage that is not used normally.