Secondary battery protection circuit comprising a security arrangement

• US 20060208850A1
• Filed: 01/30/2006
• Published: 09/21/2006
• Est. Priority Date: 03/14/2005
• Status: Abandoned Application

• Current Assignee: Mitsumi Electric Co., Ltd. (MinebeaMitsumi Inc.)
• Original Assignee: Mitsumi Electric Co., Ltd. (MinebeaMitsumi Inc.)
• Inventors: Kimura, Daisuke, Ikeuchi, Akira
• Application Number:
  US11/342,422
• Publication Number:
  US 20060208850A1
• Time in Patent Office: Days
• US Class Current: 340/5.800
• CPC Class Codes: H02J 7/00036 Charger exchanging data with battery
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence

Abstract

In a secondary battery protection circuit (200A) having a protection arrangement (210, 220, 230, 240, 250A) for protecting a secondary battery (300), by turning a discharge control switch (FET1) and a charge control switch (FET2) on and off, so as to prevent the secondary battery from overdischarging and overcharging, the secondary battery protection circuit further has a security arrangement (260, 270) for precluding counterfeit goods of a secondary pack. The security arrangement has an interface circuit (260) for interfacing to a portable unit body (500) and an authentication circuit (270) for calculating an identifier obtained by encrypting a random number received from the portable unit body to return the identifier to the portable unit body.

Claims

1. A secondary battery protection circuit (200A) comprising:

a protection arrangement (210, 220, 230, 240, 250A) for protecting a secondary battery (300), by turning a discharge control switch (FET1) and a charge control switch (FET2) on and off, so as to prevent said secondary battery from overdischarging and overcharging; and

a security arrangement (260, 270) for precluding counterfeit goods of a battery pack.

2. The secondary battery protection circuit as claimed in claim 1, wherein said protection arrangement comprises:

an overdischarge detection circuit (210) for detecting an overdischarge in said secondary battery;

an overcharge detection circuit (220) for detecting an overcharge in said secondary battery; and

a protection control logic circuit (250A), connected to said overdischarge detection circuit and said overcharge detection circuit, for controlling turning-on/off of said discharge control switch (FET1) and said charge control switch (FET2).

3. The secondary battery protection circuit as claimed in claim 2, wherein said security arrangement comprises:

an interface circuit (260) for interfacing to a portable unit body (500); and

an authentication circuit (270), connected to said interface circuit, for calculating an identifier obtained by encrypting a random number received from the portable unit body to return the identifier to the portable unit body.

4. The secondary battery protection circuit as claimed in claim 3, wherein said authentication circuit is connected to said protection control logic circuit, said authentication circuit making said protection control logic circuit turn at least one of said discharge control switch (FET1) and said charge control switch (FET2) off when decision of the counterfeit goods is made.

5. The secondary battery protection circuit as claimed in claim 1, wherein said protection arrangement comprises:

an overdischarge detection circuit (210) for detecting an overdischarge in said secondary battery;

an overcharge detection circuit (220) for detecting an overcharge in said secondary battery;

an overcurrent detection circuit (230) for detecting an overcurrent in said secondary battery; and

a protection control logic circuit (250A), connected to said overdischarge detection circuit, said overcharge detection circuit, and said overcurrent detection circuit, for controlling turning-on/off of said discharge control switch (FET1) and said charge control switch (FET2).

6. The secondary battery protection circuit as claimed in claim 5, wherein said security arrangement comprises:

an interface circuit (260) for interfacing to a portable unit body (500); and

an authentication circuit (270), connected to said interface circuit, for calculating an identifier obtained by encrypting a random number received from the portable unit body to return the identifier to the portable unit body.

7. The secondary battery protection circuit as claimed in claim 6, wherein said authentication circuit is connected to said protection control logic circuit, said authentication circuit making said protection control logic circuit turn at least one of said discharge control switch (FET1) and said charge control switch (FET2) off when decision of the counterfeit goods is made.

8. The secondary battery protection circuit as claimed in claim 1, wherein said protection arrangement comprises:

an overdischarge detection circuit (210) for detecting an overdischarge in said secondary battery;

an overcharge detection circuit (220) for detecting an overcharge in said secondary battery;

a short-circuit detection circuit (240) for detecting a short circuit between external connection terminals (P+(PA), P−

(PA)); and

a protection control logic circuit (250A), connected to said overdischarge detection circuit, said overcharge detection circuit, and said short-circuit detection circuit, for controlling turning-on/off of said discharge control switch (FET1) and said charge control switch (FET2).

9. The secondary battery protection circuit as claimed in claim 8, wherein said security arrangement comprises:

an interface circuit (260) for interfacing to a portable unit body (500); and

an authentication circuit (270), connected to said interface circuit, for calculating an identifier obtained by encrypting a random number received from the portable unit body to return the identifier to the portable unit body.

10. The secondary battery protection circuit as claimed in claim 9, wherein said authentication circuit is connected to said protection control logic circuit, said authentication circuit making said protection control logic circuit turn at least one of said discharge control switch (FET1) and said charge control switch (FET2) off when decision of the counterfeit goods is made.

11. The secondary battery protection circuit as claimed in claim 1, wherein said protection arrangement comprises:

an overdischarge detection circuit (210) for detecting an overdischarge in said secondary battery;

an overcharge detection circuit (220) for detecting an overcharge in said secondary battery;

an overcurrent detection circuit (230) for detecting an overcurrent in said secondary battery;

a short-circuit detection circuit (240) for detecting a short circuit between external connection terminals (P+(PA), P−

(PA)); and

a protection control logic circuit (250A), connected to said overdischarge detection circuit, said overcharge detection circuit, said overcurrent detection circuit, and said short-circuit detection circuit, for controlling turning-on/off of said discharge control switch (FET1) and said charge control switch (FET2).

12. The secondary battery protection circuit as claimed in claim 11, wherein said security arrangement comprises:

an interface circuit (260) for interfacing to a portable unit body (500); and

an authentication circuit (270), connected to said interface circuit, for calculating an identifier obtained by encrypting a random number received from a portable unit body to return the identifier to the portable unit body.

13. The secondary battery protection circuit as claimed in claim 12, wherein said authentication circuit is connected to said protection control logic circuit, said authentication circuit making said protection control logic circuit turn at least one of said discharge control switch (FET1) and said charge control switch (FET2) off when decision of the counterfeit goods is made.

14. A security-equipped battery pack (100B) having a pack positive electrode terminal (P+(PA)), a pack negative electrode terminal (P−

(PA)), and a pack input/output terminal (I/O(PA)), said security-equipped battery pack (100B) comprising;

a secondary battery (300) having a cathode connected to the pack positive electrode terminal and an anode;

a discharge control switch (FET1) and a charge control switch (FET2), disposed between the anode and the pack negative electrode terminal, connected in series with each other, said discharge control switch having a discharge control terminal (G1), said charge control switch having a charge control terminal (G2); and

a security-equipped secondary battery protection circuit (200A) having a protection power source terminal (VDD(PR)) connected to the cathode through a first resistor (R1), a protection ground terminal (VSS(PR)) connected to the anode, an overdischarge detection output terminal (DOUT) connected to the discharge control terminal, an overcharge detection output terminal (COUT) connected to the charge control terminal, and a protection input/output terminal (I/O(PR)) connected to the pack input/output terminal (I/O(PA)), wherein said security-equipped secondary battery protection circuit (200A) comprises;

a protection arrangement (210, 220, 230, 240, 250A), connected to the protection power source terminal, the overdischarge detection output terminal, and the overcharge detection output terminal, for protecting said secondary battery (300), by turning said discharge control switch (FET1) and said charge control switch (FET2) on and off, so as to prevent said secondary battery (300) from overdischarging and overcharging; and

a security arrangement (260, 270), connected to the protection input/output terminal, for precluding counterfeit goods of a secondary pack.

15. The security-equipped battery pack as claimed in claim 14, wherein said protection arrangement comprises:

an overdischarge detection circuit (210), connected to the protection power source terminal, for detecting an overdischarge in said secondary battery (300); and

an overcharge detection circuit (220), connected the protection power source terminal, for detecting an overcharge in said secondary battery (300); and

a protection control logic circuit (250A), connected to said overdischarge detection circuit, said overcharge detection circuit, the overdischarge detection output terminal, and the overcharge detection output terminal, for controlling turning-on/off of said discharge control switch (FET1) and said charge control switch (FET2).

16. The security-equipped battery pack as claimed in claim 15, wherein said security arrangement comprises:

an interface circuit (260), connected to the protection input/output terminal, for interfacing to a portable unit body (500); and

an authentication circuit (270), connected to said interface circuit, for calculating an identifier obtained by encrypting a random number received from the portable unit body to return the identifier to the portable unit body.

17. The security-equipped battery pack as claimed in claim 16, wherein said authentication circuit (270) is connected to said protection control logic circuit (250A), said authentication circuit making said protection control logic circuit turn at least one of said discharge control switch (FET1) and said charge control switch (FET2) off when decision of the counterfeit goods is made.

18. The security-equipped battery pack as claimed in claim 14, said security-equipped secondary battery protection circuit (200A) further having an detection input terminal (V−

) connected to the pack negative electrode terminal (P−

(PA)) through a second resistor (R2), wherein said protection arrangement comprises;

an overdischarge detection circuit (210), connected to the protection power source terminal, for detecting an overdischarge in said secondary battery (300);

an overcharge detection circuit (220), connected the protection power source terminal, for detecting an overcharge in said secondary battery (300);

an overcurrent detection circuit (230), connected to the detection input terminal, for detecting an overcurrent in said secondary battery (300); and

a protection control logic circuit (250A), connected to said overdischarge detection circuit, said overcharge detection circuit, said overcurrent detection circuit, the overdischarge detection output terminal, and the overcharge detection output terminal, for controlling turning-on/off of said discharge control switch (FET1) and said charge control switch (FET2).

19. The security-equipped battery pack as claimed in claim 18, wherein said security arrangement comprises:

an interface circuit (260), connected to the protection input/output terminal, for interfacing to a portable unit body (500); and

an authentication circuit (270), connected to said interface circuit, for calculating an identifier obtained by encrypting a random number received from the portable unit body to return the identifier to the portable unit body.

20. The security-equipped battery pack as claimed in claim 19, wherein said authentication circuit (270) is connected to said protection control logic circuit (250A), said authentication circuit making said protection control logic circuit turn at least one of said discharge control switch (FET1) and said charge control switch (FET2) off when decision of the counterfeit goods is made.

21. The security-equipped battery pack as claimed in claim 14, said security-equipped secondary battery protection circuit (200A) further having an detection input terminal (V−

) connected to the pack negative electrode terminal (P−

(PA)) through a second resistor (R2), wherein said protection arrangement comprises;

an overdischarge detection circuit (210), connected to the protection power source terminal, for detecting an overdischarge in said secondary battery (300);

an overcharge detection circuit (220), connected the protection power source terminal, for detecting an overcharge in said secondary battery (300);

a short-circuit detection circuit (240), connected to the detection input terminal, for detecting a short circuit between the pack positive electrode terminal (P+(PA)) and the pack negative electrode terminal (P−

(PA)); and

a protection control logic circuit (250A), connected to said overdischarge detection circuit, said overcharge detection circuit, said short-circuit detection circuit, the overdischarge detection output terminal, and the overcharge detection output terminal, for controlling turning-on/off of said discharge control switch (FET1) and said charge control switch (FET2).

22. The security-equipped battery pack as claimed in claim 21, wherein said security arrangement comprises:

an interface circuit (260), connected to the protection input/output terminal, for interfacing to a portable unit body (500); and

an authentication circuit (270), connected to said interface circuit, for calculating an identifier obtained by encrypting a random number received from the portable unit body to return the identifier to the portable unit body.

23. The security-equipped battery pack as claimed in claim 22, wherein said authentication circuit (270) is connected to said protection control logic circuit (250A), said authentication circuit making said protection control logic circuit turn at least one of said discharge control switch (FET1) and said charge control switch (FET2) off when decision of the counterfeit goods is made.

24. The security-equipped battery pack as claimed in claim 14, said security-equipped secondary battery protection circuit (200A) further having an detection input terminal (V−

) connected to the pack negative electrode terminal (P−

(PA)) through a second resistor (R2), wherein said protection arrangement comprises;

an overdischarge detection circuit (210), connected to the protection power source terminal, for detecting an overdischarge in said secondary battery (300);

an overcharge detection circuit (220), connected the protection power source terminal, for detecting an overcharge in said secondary battery (300);

an overcurrent detection circuit (230), connected to the detection input terminal, for detecting an overcurrent in said secondary battery (300);

a short-circuit detection circuit (240), connected to the detection input terminal, for detecting a short circuit between the pack positive electrode terminal (P+(PA)) and the pack negative electrode terminal (P−

(PA)); and

a protection control logic circuit (250A), connected to said overdischarge detection circuit, said overcharge detection circuit, said overcurrent detection circuit, said short-circuit detection circuit, the overdischarge detection output terminal, and the overcharge detection output terminal, for controlling turning-on/off of said discharge control switch (FET1) and said charge control switch (FET2).

25. The security-equipped battery pack as claimed in claim 24, wherein said security arrangement comprises:

an interface circuit (260), connected to the protection input/output terminal, for interfacing to a portable unit body (500); and

an authentication circuit (270), connected to said interface circuit, for calculating an identifier obtained by encrypting a random number received from the portable unit body to return the identifier to the portable unit body.

26. The security-equipped battery pack as claimed in claim 25, wherein said authentication circuit (270) is connected to said protection control logic circuit (250A), said authentication circuit making said protection control logic circuit turn at least one of said discharge control switch (FET1) and said charge control switch (FET2) off when decision of the counterfeit goods is made.