Electronic device

• US 10,271,401 B1
• Filed: 07/02/2018
• Issued: 04/23/2019
• Est. Priority Date: 04/19/2018
• Status: Active Grant

• Current Assignee: Asian Power Devices Inc.
• Original Assignee: Asian Power Devices Inc.
• Inventors: Hung, Tsung-Liang, Yau, Yeu-Torng
• Primary Examiner(s): Le, Tung X
• Application Number:
  US16/025,948
• Time in Patent Office: 295 Days
• Field of Search: 315309
• CPC Class Codes: H02H 1/0038 concerning the connection of the detecting means, e.g. for reducing their number
• CPC Class Codes: H02H 5/042 using temperature dependent resistors
• CPC Class Codes: H02H 7/20 for electronic equipment for converters H02H7/10; for electric measuring instruments G01R1/36; for dc voltage or current semiconductor regulators G05F1/569; for amplifiers H03F1/52; for electronic switching circuits H03K17/08
• CPC Class Codes: H05B 45/56 involving measures to prevent abnormal temperature of the LEDs
• CPC Class Codes: H05K 1/111 Pads for surface mounting, e.g. lay-out
• CPC Class Codes: H05K 1/181 associated with surface mounted components
• CPC Class Codes: H05K 2201/10022 Non-printed resistor
• CPC Class Codes: H05K 2201/10106 Light emitting diode [LED]
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

An electronic device is provided. The electronic device integrates an enable function and an over-temperature protection function (OTP) on the same line, thereby reducing the PCB layout between a microcontroller and a mainboard circuit, and further reducing the circuit complexity and cost. In addition, the negative temperature coefficient (NTC) thermistor in the electronic device is also directly coupled to a circuit pin used for the enable function of the microcontroller to serve as an over-temperature protection application. Therefore, even if the microcontroller fails, the electronic device may still use the hardware circuit structure to automatically achieve the over-temperature protection function.

Claims

1. An electronic device, comprising:

a mainboard circuit comprising an input terminal and a ground terminal;

a thermistor serially connected between the input terminal and the ground terminal of the mainboard circuit; and

a microcontroller, comprising;

a first circuit pin coupled to the input terminal of the mainboard circuit via a connection and used to detect a temperature relating to the mainboard circuit via the thermistor; and

a second circuit pin coupled to a node on the connection via a resistor and used to output an enable signal to the mainboard circuit for the mainboard circuit to determine to be in a standby mode or an operation mode according to the enable signal;

wherein the mainboard circuit further comprises;

a working circuit; and

a switching circuit having a first terminal and a second terminal respectively coupled to the working circuit and the ground terminal, and a third terminal coupled to the input terminal and controlled by the enable signal to enable or disable a conduction between the first terminal and the second terminal.

2. The electronic device according to claim 1, wherein the thermistor is a negative temperature coefficient (NTC) thermistor, and when the temperature is increased, the resistance value of the thermistor will be decreased, and the mainboard circuit enters an over-temperature protection state via the thermistor.

3. The electronic device according to claim 2, wherein the mainboard circuit is a light-emitting diode (LED) driving circuit, and the working circuit includes at least one light-emitting diode component.

4. An electronic device, comprising:

a mainboard circuit comprising an input terminal and a ground terminal;

a thermistor serially connected between the input terminal and the ground terminal of the mainboard circuit; and

a microcontroller, comprising;

a circuit pin coupled to the input terminal of the mainboard circuit via a connection and used to detect a temperature relating to the mainboard circuit via the thermistor, and used to output an enable signal to the mainboard circuit for the mainboard circuit to determine to be in a standby mode or an operation mode according to the enable signal;

wherein the mainboard circuit further comprises;

a working circuit; and

a switching circuit having a first terminal and a second terminal respectively coupled to the working circuit and the ground terminal, and a third terminal coupled to the input terminal and controlled by the enable signal to enable or disable a conduction between the first terminal and the second terminal.

5. The electronic device according to claim 4, wherein the thermistor is a negative temperature coefficient (NTC) thermistor, and when the temperature is increased, the resistance value of the thermistor will be reduced, and the mainboard circuit enters an over-temperature protection state via the thermistor.

6. The electronic device according to claim 5, wherein the mainboard circuit is a light-emitting diode (LED) driving circuit, and the working circuit includes at least one light-emitting diode component.

7. The electronic device according to claim 6, wherein the microcontroller further comprises a first internal line and a second internal line commonly coupled to the circuit pin, the first internal line is used to receive the resistance value of the thermistor, and the second internal line is used to output the enable signal.