Control circuit and control method for detecting configuration channel line and driving light emitting unit accordingly

• US 10,154,559 B1
• Filed: 07/13/2018
• Issued: 12/11/2018
• Est. Priority Date: 01/02/2018
• Status: Active Grant

• Current Assignee: Weltrend Semiconductor Inc.
• Original Assignee: Weltrend Semiconductor Inc.
• Inventors: Yang, Chih-Sheng, Liu, Jeng-Cheng
• Primary Examiner(s): Le, Don
• Application Number:
  US16/034,367
• Time in Patent Office: 151 Days
• Field of Search: 315211
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0045 concerning the insertion or the connection of the batteries
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: H05B 47/18 via data-bus transmission

Abstract

A control circuit includes a first control unit, a power unit, a driver unit, a second control unit, a power source, a first switch, a pull-up element and a second switch. The first control unit is used to detect whether a configuration channel line has a predetermined divided voltage and generate a control signal accordingly. The power unit is coupled to the configuration channel line and a power line for supplying power to the driver unit. The driver unit is used to enable or disable a light emitting unit according to the control signal. The second control unit is used to detect whether the configuration channel line has the predetermined divided voltage and control the first switch and the second switch accordingly. The first switch is coupled between a power source and the configuration channel line. The second switch is coupled between the pull-up element and the configuration channel line.

Claims

1. A control circuit comprising:

a first control unit comprising a first terminal coupled to a configuration channel line of a universal serial bus, and an output terminal configured to output a control signal, wherein the first control unit is configured to detect whether the configuration channel line has a predetermined divided voltage and generate the control signal accordingly;

a power unit comprising a first terminal coupled to a power line of the universal serial bus, a second terminal coupled to the configuration channel line, and an output terminal;

a driver unit comprising an input terminal coupled to the output terminal of the power unit, a control terminal coupled to the output terminal of the first control unit and configured to receive the control signal, and a first output terminal coupled to a first light emitting unit, wherein the driver unit is configured to enable or disable the first light emitting unit according to the control signal;

a second control unit comprising an input terminal coupled to the configuration channel line, a first output terminal configured to output a first operation signal, and a second output terminal configured to output a second operation signal, wherein the second control unit is configured to detect whether the configuration channel line has the predetermined divided voltage and generate the first operation signal and the second operation signal accordingly;

a voltage source;

a first switch comprising a first terminal coupled to the voltage source and configured to receive a first voltage, a second terminal coupled to the configuration channel line, and a control terminal coupled to the first output terminal of the second control unit;

a pull-up element; and

a second switch comprising a first terminal coupled to the pull-up element, a second terminal coupled to the configuration channel line, and a control terminal coupled to the second output terminal of the second control unit.

2. The control circuit of claim 1, wherein:

when the first control unit and the second control signal detect that the configuration channel line has the predetermined divided voltage,

the first terminal of the power unit receives a second voltage from the power line,

the control signal controls the driver unit to enable the first light emitting unit,

the first operation signal turns off the first switch,

the second operation signal turns on the second switch, and

the second voltage is provided from the output terminal of the power unit.

3. The control circuit of claim 1, wherein:

when the first control unit and the second control unit detect that the configuration channel line does not have the predetermined divided voltage, the control circuit enters a first mode and a second mode periodically;

wherein;

in the first mode,

the control signal controls the driver unit to disable the first light emitting unit,

the first operation signal turns off the first switch, and

the second operation signal turns on the second switch; and

in the second mode,

the second terminal of the power unit receives the first voltage from the configuration channel line,

the control signal controls the driver unit to enable the first light emitting unit,

the first operation signal turns on the first switch,

the second operation signal turns off the second switch, and

the first voltage is provided from the output terminal of the power unit.

4. The control circuit of claim 1, wherein:

the driver unit further comprises a second output terminal coupled to a second light emitting unit, and the driver unit is further configured to enable or disable the second light emitting unit according to the control signal.

5. The control circuit of claim 4, wherein:

when the first control unit and the second control unit detect that the configuration channel line has the predetermined divided voltage,

the first terminal of the power unit receives a second voltage from the power line,

the control signal controls the driver unit to enable at least one of the first light emitting unit and the second light emitting unit,

the first operation signal turns off the first switch,

the second operation signal turns on the second switch, and

the second voltage is provided from the output terminal of the power unit.

6. The control circuit of claim 4, wherein

when the first control unit and the second control unit detect that the configuration channel line does not have the predetermined divided voltage, the control circuit enters a first mode and a second mode periodically;

wherein;

in the first mode,

the control signal controls the driver unit to disable the first light emitting unit and the second light emitting unit,

the first operation signal turns off the first switch, and

the second operation signal turns on the second switch; and

in the second mode,

the second terminal of the power unit receives the first voltage from the configuration channel line,

the control signal controls the driver unit to enable the first light emitting unit and/or the second light emitting unit,

the first operation signal turns on the first switch,

the second operation signal turns off the second switch, and

the first voltage is provided from the output terminal of the power unit.

7. The control circuit of claim 1, wherein the first control unit further comprises a second terminal coupled to the power line, and the first control unit is further configured to detect whether the power line has a second voltage.

8. The control circuit of claim 1, wherein the pull-up element comprises a pull-up resistor or a pull-up current source.

9. A control method for controlling a control circuit, the control circuit comprising a first control unit coupled to a configuration channel line of a universal serial bus, a driver unit coupled to an output terminal of a first control unit, a first switch coupled between a voltage source and the configuration channel line, a second switch coupled between a pull-up element and the configuration channel line, and a second control unit coupled to the configuration channel line, a control terminal of the first switch and a control terminal of the second switch, and the control method comprising:

detecting whether the configuration channel line has a predetermined divided voltage by the first control unit and the second control unit; and

controlling the driver unit to enable a light emitting unit by the first control unit, and turning off the first switch and turning on the second switch by the second control unit when the configuration channel line is detected to have the predetermined divided voltage.

10. A control method for controlling a control circuit, the control circuit comprising a first control unit coupled to a configuration channel line of a universal serial bus, a driver unit coupled to an output terminal of a first control unit, a first switch coupled between a voltage source and the configuration channel line, a second switch coupled between a pull-up element and the configuration channel line, and a second control unit coupled to the configuration channel line, a control terminal of the first switch and a control terminal of the second switch, and the control method comprising:

detecting whether the configuration channel line has a predetermined divided voltage by the first control unit and the second control unit; and

the control circuit entering a first mode and a second mode periodically when the configuration channel line is not detected to have the predetermined divided voltage;

wherein;

in the first mode, the first control unit controls the driver unit to disable a light emitting unit, and the second control unit turns off the first switch and turns on the second switch; and

in the second mode, the first control unit controls the driver unit to enable the light emitting unit, and the second control unit turns on the first switch and turns off the second switch.