Voltage-detecting method and related circuits

• US 7,023,352 B2
• Filed: 05/18/2004
• Issued: 04/04/2006
• Est. Priority Date: 05/20/2003
• Status: Active Grant

• Current Assignee: Chien Holdings, LLC
• Original Assignee: BenQ Corporation (Qisda Corporation)
• Inventors: Tseng, Li-Ming, Lan, Jen-Hong
• Primary Examiner(s): NGUYEN, HUNG T
• Application Number:
  US10/709,611
• Publication Number:
  US 20040233064A1
• Time in Patent Office: 686 Days
• Field of Search: 340/636.1, 340/636.12, 340/636.15, 340/635, 340/653, 340/660, 340/662, 340/663, 320/124, 320/125, 320/136, 320/150, 320/151, 320/153
• US Class Current: 340/636.1
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• CPC Class Codes: G01R 19/16547 voltage or current in AC supplies switching for protection H02H; circuits for emergency power supply H02J9/00

Abstract

A voltage-detecting circuit includes a CPU, a comparator, a first resistor, a second resistor, and at least a power level segment detector connected in parallel with the first resistor, the power level segment detector having a third resistor and a first switch serially connected to the third resistor. The battery is electrically connected to a first input end of the comparator. The first resistor is electrically connected between a second input end of the comparator and a reference voltage. The second resistor is electrically connected between the second input end of the comparator and ground. The method includes outputting a control signal with the CPU to control the first switch by determining voltage levels at the output end of the comparator, and outputting a power indication signal with the CPU to indicate the voltage level of the battery by determining voltage levels at the output end of the comparator.

Claims

1. A voltage-detecting method for detecting power status of a battery with a voltage-detecting circuit, the voltage-detecting circuit comprising:

a processor comprising a first general purpose input/output (GPIO) port and a second GPIO port;

a comparator having a first input end connected to the battery, a second input end, and an output end connected to the first GPIO port;

a first resistor connected between the second input end of the comparator and a first voltage source;

a first power segment detection circuit connected in parallel with the first resistor, the first power segment detection circuit comprising a third resistor and a first switch serially connected to the third resistor, the first switch connected to the second GPIO port; and

a second resistor connected between the second input end of the comparator and a second voltage source;

the voltage-detecting method comprising;

outputting a first control signal with the processor to control the first switch at the second GPIO port by determining a voltage level at the first GPIO port; and

outputting a power signal with the processor by determining a voltage level at the first GPIO port.

2. The voltage-detecting method of claim 1 further comprising:

transmitting the power signal to a display device to display the power status of the battery.

3. The voltage-detecting method of claim 1, wherein the first switch is a metal oxide semiconductor (MOS) transistor.

4. The voltage-detecting method of claim 3, wherein the MOS transistor is integrated in an application specific integrated circuit (ASIC).

5. The voltage-detecting method of claim 1, wherein the processor further comprises a third GPIO port, and the voltage-detecting method further comprises:

providing at least a second power segment detection circuit connected in parallel with the second resistor, the second power segment detection circuit comprising a fourth resistor and a second switch serially connected to the fourth resistor, the second switch connected to the third GPIO port of the processor; and

outputting a second control signal with the processor to control the second switch at the third GPIO port by determining a voltage level at the first GPIO port.

6. The voltage-detecting method of claim 5, wherein the second switch is a MOS transistor.

7. The voltage-detecting method of claim 6, wherein the MOS transistor is integrated in an ASIC.

8. The voltage-detecting method of claim 1, wherein the first voltage source is ground.

9. The voltage-detecting method of claim 1, wherein the second voltage source is ground.

10. The voltage-detecting method of claim 1, wherein the comparator is integrated in an ASIC.

11. A voltage-detecting circuit comprising:

a processor comprising a first GPIO port and a second GPIO port;

a comparator having a first input end connected to a battery, a second input end, and an output end connected to the first GPIO port;

a first resistor connected between the second input end of the comparator and a first voltage source;

a first power segment detection circuit connected in parallel with the first resistor, the first power segment detection circuit comprising a third resistor and a first switch serially connected to the third resistor, the first switch connected to the second GPIO port; and

a second resistor connected between the second input end of the comparator and a second voltage source;

wherein the processor outputs a first control signal to control the first switch at the second GPIO port by determining a voltage level at the first GPIO port and then generates a power signal by determining a voltage level at the first GPIO port.

12. The voltage-detecting circuit of claim 11 further comprising:

a display device connected to the first GPIO port of the processor for displaying power status of the battery.

13. The voltage-detecting circuit of claim 11, wherein the first switch is a MOS transistor.

14. The voltage-detecting circuit of claim 13, wherein the MOS transistor is integrated in an ASIC.

15. The voltage-detecting circuit of claim 11, wherein the processor further comprises a third GPIO port, and the voltage-detecting circuit further comprises:

at least a second power segment detection circuit connected in parallel with the second resistor, the second power segment detection circuit comprising a fourth resistor and a second switch serially connected to the fourth resistor, the second switch connected to the third GPIO port of the processor;

wherein the processor outputs a second control signal to control the second switch at the third GPIO port by determining a voltage level at the first GPIO port.

16. The voltage-detecting circuit of claim 15, wherein the second switch is a MOS transistor.

17. The voltage-detecting circuit of claim 16, wherein the MOS transistor is integrated in an ASIC.

18. The voltage-detecting circuit of claim 11, wherein the first voltage source is ground.

19. The voltage-detecting circuit of claim 11, wherein the second voltage source is ground.

20. The voltage-detecting circuit of claim 11, wherein the comparator is integrated in an ASIC.