RECHARGEABLE BATTERY

• US 20120313590A1
• Filed: 06/07/2011
• Published: 12/13/2012
• Est. Priority Date: 06/07/2011
• Status: Active Grant

• Current Assignee: Synerger Incorporated
• Original Assignee: Flashsilicon, Incorporation
• Inventors: WANG, Lee Z.
• Granted Patent: US 8,742,729 B2
• Time in Patent Office: Days
• US Class Current: 320/166
• CPC Class Codes: H02J 7/007 Regulation of charging or discharging current or voltage
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices

Abstract

A rechargeable battery is disclosed. The rechargeable battery of the invention includes a high density capacitor and an integrated circuit. The high density capacitor is connected to a ground terminal and a first node carrying a first voltage. The integrated circuit includes a band gap circuit, a first detecting unit, a voltage divider, a second detecting unit and at least one low dropout voltage regulator. The band gap circuit generates a band gap voltage according to the first voltage. The first detecting unit measures the first voltage and determines whether to apply an input charging voltage to the high density capacitor. The voltage divider is connected in parallel with the high density capacitor and has a second node carrying a second voltage. The second detecting unit measures the second voltage according to the band gap voltage and determines whether to connect a third node to the first node. Each low dropout voltage regulator is connected to the third node and generates a specified voltage output and a specified current output according to the band gap voltage and the first voltage.

Claims

1. A rechargeable battery, comprising:

a high density capacitor being connected to a reference voltage terminal and a first node carrying a first voltage; and

an integrated circuit, comprising;

a band gap circuit for generating a band gap voltage according to the first voltage;

a first detecting unit for measuring the first voltage and determining whether to apply an input charging voltage to the high density capacitor;

a voltage divider being connected in parallel to the high density capacitor and having a second node carrying a second voltage;

a second detecting unit for measuring the second voltage according to the band gap voltage and determining whether to connect a third node to the first node; and

at least one low dropout voltage regulator, each being connected to the third node and generating a specified voltage output and a specified current output according to the band gap voltage and the first voltage.

2. The rechargeable battery according to claim 1, wherein the voltage divider comprising at least two capacitors connected in series and the second node is formed by the at least two capacitors.

3. The rechargeable battery according to claim 1, wherein the voltage divider comprising at least two resistors connected in series and the second node is formed by the at least two resistors.

4. The rechargeable battery according to claim 1, wherein the first detecting unit comprises:

a first comparator for comparing the input charging voltage with the first voltage to generate a first control signal; and

a first switch for connecting the first node with an input terminal carrying the input charging voltage according to the first control signal.

5. The rechargeable battery according to claim 4, wherein when the first voltage is less than the input charging voltage, the input charging voltage is provided to charge the high density capacitor, otherwise, the high density capacitor stops charging.

6. The rechargeable battery according to claim 1, wherein the second detecting unit comprises:

a second comparator for comparing the band gap voltage with the second voltage to generate a second control signal; and

a second switch for connecting the first node to the third node according to the second control signal.

7. The rechargeable battery according to claim 6, wherein when the second voltage is greater than the band gap, the first node is connected with the third node, otherwise, the first node is disconnected from the third node.

8. The rechargeable battery according to claim 1, wherein the high density capacitor and the integrated circuit are manufactured separately in two different semiconductor substrates.

9. The rechargeable battery according to claim 1, wherein the high density capacitor and the integrated circuit are integrated in a same semiconductor substrate.

10. The rechargeable battery according to claim 1, wherein a minimum of the first voltage is greater than the band gap voltage.

11. The rechargeable battery according to claim 1, wherein an amount of charges stored by the high density capacitor after fully charged is given by Q=C×

(V_chg−

V_cmin), where C denotes a capacitance of the high density capacitor, V_chg denotes a magnitude of the input charging voltage and V_cmin denotes a minimum of the first voltage that the third node remains connected with the first node.

12. The rechargeable battery according to claim 1, wherein the reference voltage terminal is a ground terminal.

13. An operating method of a rechargeable battery, the rechargeable battery at least comprising a high density capacitor, a voltage divider and at least one low dropout voltage regulator, the high density capacitor being connected to a reference voltage terminal and a first node carrying a first voltage, the voltage divider being arranged in parallel to the high density capacitor and having a second node carrying a second voltage, the method comprising the steps of:

measuring the first voltage and determining whether to apply an input charging voltage to the high density capacitor;

generating a band gap voltage according to the first voltage;

measuring the second voltage according to the band gap voltage and determining whether to supply the first voltage to the at least one low dropout voltage regulator; and

when the first voltage is supplied to the at least one low dropout voltage regulator, respectively generating specified voltage outputs and specified current outputs according to the band gap voltage and the first voltage by means of the at least one low dropout voltage regulator.

14. The method according to claim 13, wherein the voltage divider comprising at least two capacitors connected in series and the second node is formed by the at least two capacitors.

15. The method according to claim 13, wherein the voltage divider comprising at least two resistors connected in series and the second node is formed by the at least two resistors.

16. The method according to claim 13, wherein the step of measuring the first voltage comprises:

comparing the input charging voltage with the first voltage; and

when the input charging voltage is greater than the first voltage, providing the input charging voltage to charge the high density capacitor.

17. The method according to claim 13, wherein the step of measuring the second voltage comprises:

comparing the band gap voltage with the second voltage; and

when the second voltage is greater than the band gap voltage, supplying the first voltage to the at least one low dropout voltage regulator.

18. The method according to claim 13, wherein the high density capacitor, the voltage divider and the at least one low dropout voltage regulator are integrated in a same semiconductor substrate.

19. The method according to claim 13, wherein the high density capacitor is manufactured separately in a different semiconductor substrate from the voltage divider and the at least one low dropout voltage regulator.

20. The method according to claim 13, wherein a minimum of the first voltage is greater than the band gap voltage.

21. The method according to claim 13, wherein an amount of charges stored by the high density capacitor after fully charged is given by Q=C×

(V_chg−

V_cmin), where C denotes a capacitance of the high density capacitor, V_chg denotes a magnitude of the input charging voltage and V_cmin denotes a minimum of the first voltage that is allowed to be provided to the at least one low dropout voltage regulator.

22. The method according to claim 13, wherein the reference voltage terminal is a ground terminal.