Control circuit for an electronic circuit

Abstract

The utility model provides a control circuit for an electronic circuit. The electronic circuit includes a light emitting element and a control pin. The light-emitting element is coupled to the control pin. The control circuit comprises a driving circuit and at least one detection circuit. The driving circuit is coupled to the control pin. The drive circuit drives the light-emitting element during a light emission period in a drive cycle of the light-emitting element. The at least one detection circuit is coupled to the control pin. The at least one detection circuit receives the voltage value of the control pin during at least one non-light-emitting period in the driving period, and provides at least one detection result according to the voltage value of the control pin. The light-emitting element emits light during the light-emitting period and stops emitting light during the at least one non-light-emitting period. The control circuit provided by the utility model can drive the light-emitting element through a single control pin and provide a detection result according to the voltage value of the control pin.

Description

Technical Field

[0001] The utility model relates to a control circuit for an electronic circuit, and particularly to a control circuit with a low number of pins. Background Art

[0002] Generally, a control circuit can be used to control the operation of an electronic circuit and detect the circuit characteristics of the electronic circuit. The control circuit can provide corresponding operations according to the circuit characteristics of the electronic circuit, such as over-temperature protection or over-current protection. The control circuit controls the operation of the electronic circuit through control pins and detects different circuit characteristics of the electronic circuit through a plurality of detection pins.

[0003] However, based on the requirement of small volume, the number of pins between the electronic circuit and the control circuit needs to be reduced. Therefore, how to provide a control circuit with a low number of pins is one of the research focuses of those skilled in the art. Summary of the Utility Model

[0004] The utility model provides a control circuit with a low number of pins.

[0005] In an embodiment of the utility model, the control circuit is used for an electronic circuit. The electronic circuit includes a light-emitting element and a control pin. The light-emitting element is coupled to the control pin. The control circuit includes a driving circuit and at least one detection circuit. The driving circuit is coupled to the control pin. The driving circuit drives the light-emitting element during the light-emitting period in the driving cycle of the light-emitting element. Each of the at least one detection circuit is coupled to the control pin. Each of the at least one detection circuit receives a voltage value at the control pin during at least one non-light-emitting period in the driving cycle, and provides at least one detection result according to the voltage value of the control pin. The light-emitting element emits light during the light-emitting period and stops emitting light during the at least one non-light-emitting period.

[0006] In an embodiment of the utility model, the electronic circuit further includes a thermistor and a sense resistor. The light-emitting element is coupled between the control pin and a connection node. The thermistor is coupled between the control pin and the connection node. The sense resistor is coupled between the connection node and a reference low voltage. The at least one detection circuit includes a first detection circuit and a second detection circuit. The first detection circuit is coupled to the control pin. The first detection circuit generates a temperature detection signal according to the resistance value of the thermistor during a first non-light-emitting period in the driving cycle. The second detection circuit is coupled to the control pin. The second detection circuit detects the current value flowing through the sense resistor during a second non-light-emitting period in the driving cycle.

[0007] In an embodiment of the present utility model, the control circuit further includes a controller. The controller is coupled to the driving circuit, the first detection circuit, and the second detection circuit. The controller provides a first control signal to the driving circuit during the light-emitting period, provides a second control signal to the first detection circuit during the first non-light-emitting period, and provides a third control signal to the second detection circuit during the second non-light-emitting period. The driving circuit provides a driving power supply in response to the first control signal to drive the light-emitting element. The first detection circuit detects the resistance value of the thermistor through the control pin in response to the second control signal. The second detection circuit detects the current value flowing through the sensing resistor through the control pin in response to the third control signal.

[0008] In an embodiment of the present utility model, the driving circuit includes a first switch. The first end of the first switch is coupled to the driving power supply. The second end of the first switch is coupled to the control pin. The control end of the first switch is coupled to the controller.

[0009] In an embodiment of the present utility model, the first switch is turned on during the light-emitting period to provide the driving power supply to the control pin, and is turned off during the first non-light-emitting period and the second non-light-emitting period.

[0010] In an embodiment of the present utility model, the first detection circuit includes a detection signal generation circuit and a second switch. The detection signal generation circuit is coupled to the controller. The first end of the second switch is coupled to the detection signal generation circuit. The second end of the second switch is coupled to the control pin. The control end of the second switch is coupled to the controller. The second switch is turned on during the first non-light-emitting period to connect the detection signal generation circuit to the control pin, and is turned off during the light-emitting period and the second non-light-emitting period. The detection signal generation circuit generates a temperature detection signal during the first non-light-emitting period and provides the temperature detection signal to the controller.

[0011] In an embodiment of the present utility model, the detection signal generation circuit includes a current source circuit, a first transistor, a first buffer, a second buffer, and a resistor. The current source circuit is coupled to a first node and a second node. The first end of the first transistor is coupled to the first node. The second end of the first transistor is coupled to the second end of the second switch. The first input terminal of the first buffer receives a reference voltage. The second input terminal of the first buffer is coupled to the second end of the second switch. The output terminal of the first buffer is coupled to the control end of the first transistor. The first input terminal of the second buffer is coupled to the second node. The second input terminal of the second buffer is coupled to the output terminal of the second buffer and the controller. The resistor is coupled between the second node and the reference low voltage.

[0012] In an embodiment of the present utility model, the current source circuit includes a second transistor and a third transistor. A first end of the second transistor is coupled to a reference high voltage. A second end of the second transistor is coupled to a control end of the second transistor and a first node. A first end of the third transistor is coupled to the reference high voltage. A second end of the third transistor is coupled to a second node. A control end of the third transistor is coupled to the control end of the second transistor.

[0013] In an embodiment of the present utility model, the second detection circuit includes a third switch and a sampling circuit. A first end of the third switch is coupled to a control pin. A control end of the third switch is coupled to a controller. The sampling circuit is coupled to a second end of the third switch and the controller. The third switch is turned on during a second non-light emitting period to connect the sampling circuit to the control pin and is turned off during a light emitting period and a first non-light emitting period. The sampling circuit receives a voltage value at the control pin during the second non-light emitting period and detects a current value flowing through the sense resistor based on the voltage value at the control pin.

[0014] In an embodiment of the present utility model, the second detection circuit further includes an amplifier. The amplifier is coupled between the second end of the third switch and the sampling circuit. The amplifier amplifies the voltage value at the control pin during the second non-light emitting period.

[0015] Based on the above, the control circuit can drive the light emitting element through a single control pin and provide a detection result based on the voltage value of the control pin. The control circuit does not need to use an additional detection pin to provide the detection result. In this way, the volume of the control circuit and the volume of the electronic circuit can be reduced. Description of the Drawings

[0016] Figure 1 is a schematic diagram of an electronic device according to an embodiment of the present utility model;

[0017] Figure 2 is a schematic diagram of an electronic device according to an embodiment of the present utility model;

[0018] Figure 3 is a driving timing diagram of a light emitting element according to an embodiment of the present utility model;

[0019] Figure 4 is a schematic diagram of an electronic device according to an embodiment of the present utility model.

[0020] Description of Reference Numerals

[0021] 10, 20, 30: Electronic device

[0022] 100, 200, 300: Control circuit

[0023] 110, 210, 310: Driving circuit

[0024] 120, 220_1, 220_2, 320_1, 320_2: Detection circuits

[0025] 230, 330: Controllers

[0026] 321_1: Detection signal generation circuit

[0027] 321_2: Sampling circuit

[0028] 322_2: Amplifier

[0029] AVDD: Drive power supply

[0030] BF1, BF2: Buffers

[0031] CS: Current source circuit

[0032] DP: Drive period

[0033] EC: Electronic circuit

[0034] I1, I2: Currents

[0035] IL: Load current

[0036] LE: Light-emitting element

[0037] ND: Connection node

[0038] ND1: First node

[0039] ND2: Second node

[0040] P1: Light-emitting period

[0041] P2: First non-light-emitting period

[0042] P3: Second non-light-emitting period

[0043] PINC: Control pin

[0044] RD, RD1, RD2: Detection results

[0045] RR: Resistor

[0046] RS: Sensing resistor

[0047] RT: Thermistor

[0048] SC1: First control signal

[0049] SC2: Second control signal

[0050] SC3: Third control signal

[0051] ST: Temperature detection signal

[0052] SW1: First switch

[0053] SW2: Second switch

[0054] SW3: Third switch

[0055] T1, T2, T3: Transistors

[0056] V1: Reference voltage

[0057] Vd1, Vd2: Voltage differences

[0058] VH: Reference high voltage

[0059] VL: Reference low voltage Detailed implementation manners

[0060] Some embodiments of the present utility model will be described in detail with reference to the accompanying drawings hereinafter. For the component symbols cited in the following description, when the same component symbols appear in different drawings, they will be regarded as the same or similar components. These embodiments are only a part of the present utility model and do not disclose all the implementable manners of the present utility model. More precisely, these embodiments are only examples within the scope of the patent application of the present utility model.

[0061] Please refer to Figure 1 , Figure 1 , which is a schematic diagram of an electronic device shown according to an embodiment of the present utility model. In this embodiment, the electronic device 10 includes a control circuit 100 and an electronic circuit EC. The electronic circuit EC includes a light-emitting element LE and a control pin PINC. The light-emitting element LE is coupled to the control pin PINC. In this embodiment, the light-emitting element LE may be a circuit including at least one light-emitting diode in any form, but the present utility model is not limited to this embodiment. The control pin PINC may be a pad or an electrical connection structure, but the present utility model is not limited to this embodiment. The electronic circuit EC may be a functional circuit in the electronic device. For example, the electronic circuit EC may be a power converter or a chip in any form, but the present utility model is not limited thereto.

[0062] In this embodiment, the control circuit 100 includes a driving circuit 110 and a detecting circuit 120. The driving circuit 110 is coupled to the control pin PINC. The driving circuit 110 drives the light-emitting element LE during the light-emitting period in the driving cycle DP. The detecting circuit 120 is coupled to the control pin PINC. The detecting circuit 120 receives the voltage value at the control pin PINC during the non-light-emitting period in the driving cycle DP and provides a detection result RD based on the voltage value at the control pin PINC. In this embodiment, the light-emitting element LE may operate based on the driving cycle DP. The light-emitting element LE emits light during the light-emitting period and stops emitting light during the non-light-emitting period.

[0063] In this embodiment, the provided detection result RD may be, for example, one of the load current associated with the electronic circuit EC and the temperature of the electronic circuit EC.

[0064] It is worth mentioning here that based on the driving period DP, the control circuit 100 can drive the light-emitting element LE through the control pin PINC. In addition, the control circuit 100 can receive the voltage value at the control pin PINC during the non-light-emitting period in the driving period DP and provide the detection result RD according to the voltage value of the control pin PINC. The control circuit 100 can drive the light-emitting element LE through a single control pin PINC and provide the detection result RD according to the voltage value of the control pin PINC. The control circuit 100 does not need to use an additional detection pin to provide the detection result RD. In this way, the volume of the control circuit 100 and the volume of the electronic circuit EC can be reduced.

[0065] In this embodiment, the duty cycle for driving the light-emitting element LE can be determined by the time length of the light-emitting period and the time length of the non-light-emitting period.

[0066] The control circuit 100 of this embodiment takes the inclusion of a single detection circuit 120 as an example. However, the present invention is not limited thereto. In some embodiments, the control circuit 100 may include multiple detection circuits for detecting different circuit characteristics of the electronic circuit EC.

[0067] Please refer to Figure 2 , Figure 2 is a schematic diagram of an electronic device shown according to an embodiment of the present invention. In this embodiment, the electronic device 20 includes a control circuit 200 and an electronic circuit EC. The electronic circuit EC includes a light-emitting element LE, a thermistor RT, a sensing resistor RS, and a control pin PINC. The light-emitting element LE is coupled between the control pin PINC and the connection node ND. The thermistor RT is coupled between the control pin PINC and the connection node ND. The sensing resistor RS is coupled between the connection node ND and a reference low voltage VL (such as ground).

[0068] In this embodiment, the control circuit 200 includes a driving circuit 210 and detection circuits 220_1, 220_2. The driving circuit 210 is coupled to the control pin PINC. The driving circuit 210 drives the light-emitting element LE during the light-emitting period in the driving period DP.

[0069] The detection circuit 220_1 is coupled to the control pin PINC. The detection circuit 220_1 generates a temperature detection signal ST according to the resistance value of the thermistor RT during the first non-light-emitting period in the driving cycle DP. For example, during the first non-light-emitting period, the detection circuit 220_1 can obtain the voltage difference Vd1 between both ends of the thermistor RT through the control pin PINC, and provide a sensed current value according to the voltage difference Vd1 between both ends of the thermistor RT. Therefore, during the first non-light-emitting period, the control circuit 200 can generate a temperature detection signal ST according to the sensed current value. The temperature detection signal ST can be a detection result RD1. The temperature detection signal ST is related to the temperature of the electronic circuit EC during operation. The control circuit 200 can use the temperature detection signal ST to perform over-temperature protection on the electronic circuit EC.

[0070] The detection circuit 220_2 is coupled to the control pin PINC. The detection circuit 220_2 detects the current value flowing through the sense resistor RS during the second non-light-emitting period in the driving cycle DP. In this embodiment, during the second non-light-emitting period, the control circuit 200 does not provide a signal or power supply to the control pin PINC. The voltage value at the control pin PINC is substantially equal to the voltage difference Vd2 between both ends of the sense resistor RS. Therefore, the detection circuit 220_2 can obtain the voltage difference Vd2 between both ends of the sense resistor RS through the control pin PINC, and obtain the current value flowing through the sense resistor RS according to the voltage difference Vd2 between both ends of the sense resistor RS. In the electronic circuit EC, the current value flowing through the sense resistor RS is equal to the current value of the load current IL flowing into the connection node ND. In other words, the detection circuit 220_2 can obtain the current value of the load current IL according to the voltage difference Vd2 between both ends of the sense resistor RS and the resistance value of the sense resistor RS. The current value of the load current IL can be another detection result RD2. During the second non-light-emitting period, the control circuit 200 can use the voltage value at the control pin PINC to perform over-current protection on the electronic circuit EC.

[0071] In this embodiment, the controller 230 is, for example, a central processing unit (CPU), or other programmable general-purpose or special-purpose microprocessors, digital signal processors (DSPs), programmable controllers, application specific integrated circuits (ASICs), programmable logic devices (PLDs), or other similar devices, or combinations of these devices, which can load and execute computer programs.

[0072] In some embodiments, one of the detection circuits 220_1 and 220_2 may be omitted.

[0073] Please refer to Figure 2 and Figure 3 , Figure 3 is a driving timing diagram of a light-emitting element shown in an embodiment of the present invention. Figure 3 Shows a driving period DP for the light-emitting element LE. In this embodiment, the driving period DP includes a light-emitting period P1, a first non-light-emitting period P2, and a second non-light-emitting period P3. Taking this embodiment as an example, the first non-light-emitting period P2 is after the light-emitting period P1. The second non-light-emitting period P3 is after the first non-light-emitting period P2. The light-emitting period P1 of the next driving period DP is after the second non-light-emitting period P3, and so on.

[0074] In some embodiments, the second non-light-emitting period P3 is after the light-emitting period P1. The first non-light-emitting period P2 is after the second non-light-emitting period P3. The light-emitting period P1 of the next driving period DP is after the first non-light-emitting period P2, and so on.

[0075] In this embodiment, the ratio of the time length of the light-emitting period P1 in the driving period DP can determine the duty cycle for driving the light-emitting element LE. For example, the ratio of the time length of the light-emitting period P1 in the driving period DP is equal to 50%. In other words, the time length of the light-emitting period P1 is equal to the sum of the time lengths of the first non-light-emitting period P2 and the second non-light-emitting period P3. Therefore, the duty cycle is equal to 50%. For example, the ratio of the time length of the light-emitting period P1 in the driving period DP is equal to 90%. The sum of the time lengths of the first non-light-emitting period P2 and the second non-light-emitting period P3 in the driving period DP is equal to 10%. Therefore, the duty cycle is equal to 90%.

[0076] Please refer to Figure 3 and Figure 4 , Figure 4 is a schematic diagram of an electronic device shown in an embodiment of the present invention. In this embodiment, the electronic device 30 includes a control circuit 300 and an electronic circuit EC. The electronic circuit EC includes a light-emitting element LE, a thermistor RT, a sensing resistor RS, and a control pin PINC. The light-emitting element LE is coupled between the control pin PINC and a connection node ND. The thermistor RT is coupled between the control pin PINC and the connection node ND. The sensing resistor RS is coupled between the connection node ND and a reference low voltage VL (such as ground).

[0077] In this embodiment, the control circuit 300 includes a driving circuit 310, detection circuits 320_1, 320_2, and a controller 330. The driving circuit 310 is coupled to the control pin PINC. The driving circuit 310 drives the light-emitting element LE during the light-emitting period P1 in the driving cycle DP.

[0078] The detection circuit 320_1 is coupled to the control pin PINC. The detection circuit 320_1 generates a temperature detection signal ST according to the resistance value of the thermistor RT during the first non-light-emitting period P2 in the driving cycle DP. The detection circuit 320_2 is coupled to the control pin PINC. The detection circuit 320_2 detects the current value flowing through the sense resistor RS during the second non-light-emitting period P3 in the driving cycle DP.

[0079] In this embodiment, the controller 330 is coupled to the driving circuit 310, the detection circuits 320_1, 320_2. The controller 330 provides a first control signal SC1 to the driving circuit 310 during the light-emitting period P1, provides a second control signal SC2 to the detection circuit 320_1 during the first non-light-emitting period P2, and provides a third control signal SC3 to the detection circuit 320_2 during the second non-light-emitting period P3. The driving circuit 310 provides a driving power supply AVDD in response to the first control signal SC1 to drive the light-emitting element LE. The detection circuit 320_1 detects the resistance value of the thermistor RT through the control pin PINC in response to the second control signal SC2. The detection circuit 320_2 detects the current value flowing through the sense resistor RS through the control pin PINC in response to the third control signal SC3.

[0080] In this embodiment, the driving circuit 310 includes a first switch SW1. The first end of the first switch SW1 is coupled to the driving power supply AVDD. The second end of the first switch SW1 is coupled to the control pin PINC. The control end of the first switch SW1 is coupled to the controller 330.

[0081] During the light-emitting period P1, the control end of the first switch SW1 receives the first control signal SC1 from the controller 330. Therefore, the first switch SW1 is turned on during the light-emitting period P1 to provide the driving power supply AVDD to the control pin PINC. Therefore, during the light-emitting period P1, the light-emitting element LE is driven to emit light. In addition, during the first non-light-emitting period P2 and the second non-light-emitting period P3, the first switch SW1 does not receive the first control signal SC1. Therefore, the first switch SW1 is turned off during the first non-light-emitting period P2 and the second non-light-emitting period P3.

[0082] In this embodiment, the detection circuit 320_1 includes a detection signal generation circuit 321_1 and a second switch SW2. The detection signal generation circuit 321_1 is coupled to the controller 330. The first end of the second switch SW2 is coupled to the detection signal generation circuit 321_1. The second end of the second switch SW2 is coupled to the control pin PINC. The control end of the second switch SW2 is coupled to the controller 330.

[0083] During the first non-light-emitting period P2, the control end of the second switch SW2 receives a second control signal SC2 from the controller 330. Therefore, the second switch SW2 is turned on to connect the detection signal generation circuit 321_1 to the control pin PINC. The detection signal generation circuit 321_1 generates a temperature detection signal ST during the first non-light-emitting period P2 and provides the temperature detection signal ST to the controller 330. During the light-emitting period P1 and the second non-light-emitting period P3, the second switch SW2 does not receive the second control signal SC2. Therefore, the second switch SW2 is turned off. The detection signal generation circuit 321_1 does not operate.

[0084] In this embodiment, the detection signal generation circuit 321_1 includes a current source circuit CS, a transistor T1, buffers BF1, BF2, and a resistor RR. The current source circuit CS is coupled to a first node ND1 and a second node ND2. The first end of the transistor T1 is coupled to the first node ND1. The second end of the transistor T1 is coupled to the second end of the second switch SW2. The first input terminal of the buffer BF1 receives a reference voltage V1. The second input terminal of the buffer BF1 is coupled to the second end of the second switch SW2. The output terminal of the buffer BF1 is coupled to the control end of the transistor T1. The first input terminal of the buffer BF2 is coupled to the second node ND2. The second input terminal of the buffer BF2 is coupled to the output terminal of the buffer BF2 and the controller 330. The output terminal of the buffer BF2 is used to output the temperature detection signal ST. The resistor RR is coupled between the second node ND2 and the reference low voltage VL.

[0085] In this embodiment, the current source circuit CS includes transistors T2, T3. The first end of the transistor T2 is coupled to the reference high voltage VH. The second end of the transistor T2 is coupled to the control end of the transistor T2 and the first node ND1. The first end of the transistor T3 is coupled to the reference high voltage VH. The second end of the transistor T3 is coupled to the second node ND2. The control end of the transistor T3 is coupled to the control end of the transistor T2. The transistors T2, T3 are N-type transistors respectively, but the present invention is not limited thereto.

[0086] For example, the voltage value of the reference voltage V1 is equal to 1 volt, but the present invention is not limited thereto. The first input terminal of the buffer BF1 can be a non-inverting input terminal. The second input terminal of the buffer BF1 can be an inverting input terminal. The transistor T1 is an N-type transistor. Therefore, the buffer BF1 and the transistor T1 form a Low-dropout regulator (LDO) circuit. In addition, during the first non-light-emitting period P2, the second switch SW2 is turned on. The current source circuit CS, the thermistor RT, and the sense resistor RS together form a current mirror circuit. Therefore, the current value of the current I1 flowing through the first node ND1, the transistor T1, the thermistor RT, and the sense resistor RS is proportional to the current value of the current I2 flowing through the second node ND2 and the resistor RR.

[0087] For example, the thermistor RT has a negative temperature coefficient (NTC). When the temperature of the electronic circuit EC decreases, the resistance value of the thermistor RT is increased. The current value of the current I1 is decreased. The current value of the current I2 is decreased. The voltage value at the second node ND2 is decreased. Therefore, the voltage value of the temperature detection signal ST is decreased.

[0088] When the temperature of the electronic circuit EC increases, the resistance value of the thermistor RT is decreased. The current value of the current I1 is increased. The current value of the current I2 is increased. The voltage value at the second node ND2 is increased. Therefore, the voltage value of the temperature detection signal ST is increased. The controller 330 can perform an over-temperature protection operation on the electronic circuit EC according to the voltage value of the temperature detection signal ST.

[0089] In this embodiment, the detection circuit 320_2 includes a third switch SW3 and a sampling circuit 321_2. The first end of the third switch SW3 is coupled to the control pin PINC. The control end of the third switch SW3 is coupled to the controller 330. The sampling circuit 321_2 is coupled to the second end of the third switch SW3 and the controller 330.

[0090] During the second non-light-emitting period P3, the control end of the third switch SW3 receives a third control signal SC3 from the controller 330. Therefore, the third switch SW3 is turned on during the second non-light-emitting period P3 to connect the sampling circuit 321_2 to the control pin PINC. During the light-emitting period P1 and the first non-light-emitting period P2, the control end of the third switch SW3 does not receive the third control signal SC3. Therefore, the third switch SW3 is turned off.

[0091] In this embodiment, the sampling circuit 321_2 receives the voltage value at the control pin PINC during the second non-light-emitting period P3, and detects the current value flowing through the sense resistor RS based on the voltage value at the control pin PINC. It should be noted that during the second non-light-emitting period P3, the control circuit 300 does not provide a signal or power supply to the control pin PINC. The voltage value at the control pin PINC is approximately equal to the voltage difference Vd2 between the two ends of the sense resistor RS (i.e., the voltage value at the connection node ND). The current value flowing through the sense resistor RS is equal to the current value of the load current IL flowing into the connection node ND. Therefore, during the second non-light-emitting period P3, the controller 330 obtains the current value of the load current IL at the connection node ND based on the voltage value at the control pin PINC and the resistance value of the sense resistor RS. During the second non-light-emitting period P3, the controller 330 can use the voltage value at the control pin PINC to perform overcurrent protection.

[0092] In addition, the sampling circuit 321_2 can also save the data of the voltage value at the control pin PINC received during the second non-light-emitting period P3. The data saved by the sampling circuit 321_2 is associated with the voltage difference Vd2 between the two ends of the sense resistor RS. The controller 330 receives the data during the second non-light-emitting period P3 for overcurrent protection, and uses the data to obtain the voltage difference Vd1 between the two ends of the thermistor RT during the first non-light-emitting period P2. Further, the controller 330 can obtain the current value of the current I2 based on the voltage value of the temperature detection signal ST and the resistance value of the resistor RR. The controller 330 can obtain the current value of the current I1 based on the current value of the current I2, and obtain the voltage value at the control pin PINC during the first non-light-emitting period P2 based on the current value of the current I1. During the first non-light-emitting period P2, the controller 330 subtracts the voltage difference Vd2 from the voltage value at the control pin PINC to obtain the voltage difference Vd1 between the two ends of the thermistor RT. Therefore, the controller 330 can obtain the resistance value of the thermistor RT based on the current value of the current I1 and the voltage difference Vd1 between the two ends of the thermistor RT. The controller 330 obtains the temperature of the electronic circuit EC based on the resistance value of the thermistor RT. In this way, the data saved by the sampling circuit 321_2 helps to improve the accuracy of the controller 330 in judging the temperature of the electronic circuit EC.

[0093] In this embodiment, the detection circuit 320_2 further includes an amplifier 322_2. The amplifier 322_2 is coupled between the second end of the third switch SW3 and the sampling circuit 321_2. The amplifier 322_2 amplifies the voltage value at the control pin PINC during the second non-light-emitting period P3. For example, the resistance value of the sense resistor RS is low. The resistance value of the sense resistor RS is, for example, equal to 5 milliohms, but the present invention is not limited thereto. Therefore, during the second non-light-emitting period P3, the voltage value at the control pin PINC may be very small. The controller 330 may make a misjudgment or ignore it due to the very small voltage value. During the second non-light-emitting period P3, the amplifier 322_2 can amplify the voltage value at the control pin PINC to generate a detection result (such as Figure 2 the detection result RD2 shown). Therefore, the controller 330 will not misjudge or ignore the voltage value at the control pin PINC. The controller 330 can know the amplification factor of the amplifier 322_2. When receiving the detection result from the sampling circuit 321_2, the controller 330 can restore the detection result from the sampling circuit 321_2 to the voltage value at the control pin PINC according to the amplification factor of the amplifier 322_2. In this way, the controller 330 can still provide accurate overcurrent protection.

[0094] In this embodiment, the amplifier 322_2 can be provided by an analog-to-digital converter (ADC) or a circuit including an operational amplifier.

[0095] In summary, the control circuit is connected to the electronic circuit via a single control pin. The control circuit can drive the light-emitting element through a single control pin and provide at least one detection result according to the voltage value of the control pin. The control circuit does not need to use an additional detection pin to provide the detection result of the electronic circuit. In this way, the volume of the control circuit and the volume of the electronic circuit can be reduced.

[0096] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control circuit for an electronic circuit, characterized in that: The electronic circuit comprises a light emitting element and a control pin, wherein the light emitting element is coupled to the control pin, and the control circuit comprises: a driving circuit coupled to the control pin and configured to drive the light emitting element during a light emitting period of a driving cycle of the light emitting element; and At least one detection circuit, each coupled to the control pin, is configured to receive a voltage value at the control pin during at least one non-light-emitting period in the driving cycle, and provide at least one detection result according to the voltage value of the control pin, The light emitting element emits light during the light emitting period and stops emitting light during the at least one non-light emitting period.

2. The control circuit according to claim 1, characterized in that: The electronic circuit also includes a thermistor and a sensing resistor, The light emitting element is coupled between the control pin and the connection node. The thermistor is coupled between the control pin and the connection node, The sensing resistor is coupled between the connection node and a reference low voltage, and The at least one detection circuit comprises: A first detection circuit coupled to the control pin and configured to generate a temperature detection signal according to a resistance value of the thermistor during a first non-light-emitting period in the driving cycle; and The second detection circuit is coupled to the control pin and is configured to detect a current value flowing through the sensing resistor during a second non-light-emitting period in the driving cycle.

3. The control circuit according to claim 2, characterized in that: The control circuit further comprises: a controller, coupled to the driving circuit, the first detection circuit, and the second detection circuit, configured to provide a first control signal to the driving circuit during the light-emitting period, provide a second control signal to the first detection circuit during the first non-light-emitting period, and provide a third control signal to the second detection circuit during the second non-light-emitting period, wherein the driving circuit provides a driving power supply in response to the first control signal to drive the light emitting element, wherein the first detection circuit detects the resistance value of the thermistor through the control pin in response to the second control signal, and The second detection circuit detects a current value flowing through the sensing resistor via the control pin in response to the third control signal.

4. The control circuit according to claim 3, characterized in that: The driving circuit comprises: A first switch, wherein a first end of the first switch is coupled to the driving power source, a second end of the first switch is coupled to the control pin, and a control end of the first switch is coupled to the controller.

5. The control circuit according to claim 4, characterized in that: The first switch is turned on during the light emitting period to provide the driving power to the control pin, and is turned off during the first non-light emitting period and the second non-light emitting period.

6. The control circuit according to claim 3, characterized in that: The first detection circuit comprises: A detection signal generating circuit coupled to the controller; and a second switch, wherein a first end of the second switch is coupled to the detection signal generating circuit, a second end of the second switch is coupled to the control pin, and a control end of the second switch is coupled to the controller, wherein the second switch is turned on during the first non-luminous period to connect the detection signal generating circuit to the control pin, and is turned off during the luminous period and the second non-luminous period, and The detection signal generating circuit generates the temperature detection signal during the first non-light emitting period, and provides the temperature detection signal to the controller.

7. The control circuit according to claim 6, characterized in that: The detection signal generating circuit comprises: A current source circuit coupled to the first node and the second node; a first transistor, wherein a first terminal of the first transistor is coupled to the first node, and a second terminal of the first transistor is coupled to a second terminal of the second switch; A first buffer, wherein a first input terminal of the first buffer receives a reference voltage, a second input terminal of the first buffer is coupled to a second terminal of the second switch, and an output terminal of the first buffer is coupled to a control terminal of the first transistor; a second buffer, a first input terminal of the second buffer being coupled to the second node, a second input terminal of the second buffer being coupled to an output terminal of the second buffer and the controller; and The resistor is coupled between the second node and a reference low voltage.

8. The control circuit according to claim 7, characterized in that: The current source circuit comprises: a second transistor, a first terminal of the second transistor being coupled to a reference high voltage, and a second terminal of the second transistor being coupled to a control terminal of the second transistor and the first node; and A third transistor, wherein a first terminal of the third transistor is coupled to a reference high voltage, a second terminal of the third transistor is coupled to the second node, and a control terminal of the third transistor is coupled to the control terminal of the second transistor.

9. The control circuit according to claim 3, characterized in that: The second detection circuit comprises: a third switch, a first end of the third switch being coupled to the control pin, and a control end of the third switch being coupled to the controller; and a sampling circuit coupled to the second end of the third switch and the controller, wherein the third switch is turned on during the second non-light-emitting period to connect the sampling circuit to the control pin and is turned off during the light-emitting period and the first non-light-emitting period, and The sampling circuit receives the voltage value at the control pin during the second non-light-emitting period, and detects the current value flowing through the sensing resistor according to the voltage value at the control pin.

10. The control circuit according to claim 9, characterized in that: The second detection circuit also includes: The amplifier is coupled between the second end of the third switch and the sampling circuit, and is configured to amplify the voltage value at the control pin during the second non-light-emitting period.

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