Device and method using a keyboard controller and voltage detection circuitry for battery charging

• US 9,172,269 B2
• Filed: 09/14/2012
• Issued: 10/27/2015
• Est. Priority Date: 02/24/2012
• Status: Active Grant

• Current Assignee: Wistron Corporation
• Original Assignee: Wistron Corporation
• Inventors: Chen, Chien-Liang, Lee, Chun-Ta
• Primary Examiner(s): Whitmore, Stacy
• Application Number:
  US13/619,491
• Publication Number:
  US 20130221902A1
• Time in Patent Office: 1,138 Days
• Field of Search: 320/128, 320/132, 320/134, 320/137, 320162-163
• US Class Current: 1/1
• CPC Class Codes: H02H 7/18 for batteries; for accumulators
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/0036 using connection detecting circuits H02J7/0034 takes precedence
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current
• CPC Class Codes: H02J 7/00716 in response to integrated charge or discharge current
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage

Abstract

A charging device including a charging circuit, a voltage detection circuit, and a keyboard controller is provided. The charging circuit receives a charging power source, and produces a battery-charging power source at a first node by the charging power source to charge a battery. The voltage detection circuit detects a voltage at the first node, and produces a voltage detection result. The keyboard controller determines whether the voltage at the first node is less than a predetermined voltage according to the voltage detection result, and determines whether a predetermined condition has been satisfied, wherein the predetermined condition includes the voltage at the first node being less than the predetermined voltage, and the keyboard controller is arranged to force the charging circuit to stop producing the battery-charging power source at the first node when the predetermined condition has been satisfied.

Claims

1. A charging device, comprising:

a charging circuit, receiving a charging power source, and producing a battery-charging power source at a first node by the charging power source to charge a battery;

a voltage detection circuit, detecting a voltage at the first node, and producing a voltage detection result; and

a keyboard controller, determining whether the voltage at the first node is lower than a predetermined voltage according to the voltage detection result, and determining whether a predetermined condition has been satisfied, wherein the predetermined condition comprises the voltage at the first node being lower than the predetermined voltage, and the keyboard controller forces the charging circuit to stop producing the battery-charging power source at the first node when the predetermined condition has been satisfied;

wherein the keyboard controller determines whether a charging current flowing to the battery from the first node is less than a predetermined current value when receiving the charging power source, wherein the charging current is produced by the charging power source, and the predetermined condition further comprises the charging current being less than the predetermined current value.

2. The charging device as claimed in claim 1, wherein the voltage detection circuit comprises:

a zener diode, having a cathode coupled to the first node and an anode coupled to a second node;

a first resistor, having a first terminal coupled to the second node and a second terminal coupled to a ground;

a switching transistor, having a control terminal coupled to the second node, a drain terminal coupled to the keyboard controller and a source terminal coupled to the ground; and

a second resistor, having a first terminal coupled to a voltage source and a second terminal coupled to the drain terminal of the switching transistor.

3. The charging device as claimed in claim 2, wherein the keyboard controller determines whether the voltage at the first node is lower than the predetermined voltage according to a signal at the drain terminal of the switching transistor.

4. The charging device as claimed in claim 1, wherein the voltage detection circuit comprises:

a first resistor, having a first terminal coupled to a voltage source and a second terminal coupled to a second node;

a second resistor, having a first terminal coupled to the second node and a second terminal coupled to a ground, wherein the first resistor and the second resistor divide the voltage source to produce the predetermined voltage at the second node; and

a comparator, having a first input terminal coupled to the first node, a second input terminal coupled to the second node, and an output terminal producing a compare signal, wherein the compare signal is provided to the keyboard controller.

5. The charging device as claimed in claim 4, wherein the keyboard controller determines whether the voltage at the first node is lower than the predetermined voltage according to the compare signal.

6. The charging device as claimed in claim 1, wherein the keyboard controller determines whether the charging device is in a charging environment and whether an adapter used for providing the charging power source is overloaded, wherein the predetermined condition further comprises the charging device being in the charging environment and the adapter not being overloaded.

7. The charging device as claimed in claim 6, wherein the keyboard controller determines whether the charging device is in the charging environment according to whether the adapter and the battery are connected to the charging device, and determines whether the charging device is in the charging environment according to whether a signal of the battery is normal and indicates that the battery needs to be charged.

8. The charging device as claimed in claim 1, further comprising a system management bus coupled between the keyboard controller and the battery, wherein a determine signal of the system management bus corresponds to the charging current flowing through the battery, and the keyboard controller determines whether the charging current is less than the predetermined current value according to the determine signal.

9. The charging device as claimed in claim 1, further comprising a sensing resistor coupled between the first node and the battery, wherein the keyboard controller determines whether the charging current is less than the predetermined current value according to a current flowing through the sensing resistor.

10. The charging device as claimed in claim 1, wherein the keyboard controller determines whether the charging device is in a charging environment and whether an adapter is overloaded, wherein the predetermined condition further comprises the charging device being in the charging environment and the adapter not being overloaded.

11. The charging device as claimed in claim 10, wherein the keyboard controller determines whether the charging device is in the charging environment according to whether the adapter and the battery are connected to the charging device, and determine whether the charging device is in the charging environment according to whether a signal of the battery is normal and indicates that the battery needs to be charged.

12. A charging method, applied to a charging device used to charge a battery, comprising:

receiving a charging power source;

producing a battery-charging power source at a first node, by the charging power source, to charge the battery;

detecting a voltage at the first node when receiving the charging power source, and producing a voltage detection result accordingly;

determining whether the voltage at the first node is lower than a predetermined voltage according to the voltage detection result;

determining whether a charging current flowing to the battery from the first node is less than a predetermined current value when receiving the charging power source, wherein the charging current is produced by the charging power source, and a predetermined condition comprises the charging current being less than the predetermined current value;

determining whether the predetermined condition has been satisfied; and

forcing the charging circuit to stop producing the battery-charging power source at the first node when the predetermined condition has been satisfied, wherein the predetermined condition comprises the voltage of the first node being lower than a predetermined voltage.

13. The charging method as claimed in claim 12, further comprising determining whether the charging device is in a charging environment and whether an adapter used for providing the charging power source is overloaded, wherein the predetermined condition further comprises the charging device being in the charging environment and the adapter not being overloaded.

14. The charging method as claimed in claim 13, wherein step of determining whether the charging device is in the charging environment comprises:

determining whether the adapter and the battery are connected to the charging device; and

determining whether a signal of the battery is normal and indicates that the battery needs to be charged.

15. The charging method as claimed in claim 12, wherein step of determining whether the charging current is less than the predetermined current value comprises determining whether the charging current is less than the predetermined current value according to a determine signal of a system management bus.

16. The charging method as claimed in claim 12, wherein step of determining whether the charging current is less than the predetermined current value comprises determining whether the charging current is less than the predetermined current value according to a current flowing through a sensing resistor.

17. The charging method as claimed in claim 12, further comprising determining whether the charging device is in a charging environment and whether an adapter is overload when the voltage at the first node is lower than the predetermined voltage and the charging current is less than the predetermined current value, wherein the predetermined condition further comprises the charging device being in the charging environment and the adapter not being overloaded.

18. The charging method as claimed in claim 17, wherein step of determining whether the charging device is in the charging environment comprises:

determining whether the adapter and the battery are connected to the charging device; and

determining whether a signal of the battery is normal and indicates that the battery needs to be charged.