CN112996189B9

CN112996189B9 - LED driving device and driving control circuit thereof

Info

Publication number: CN112996189B9
Application number: CN202110381012.3A
Authority: CN
Inventors: 叶美盼
Original assignee: Hangzhou Silan Microelectronics Co Ltd
Current assignee: Hangzhou Silan Microelectronics Co Ltd
Priority date: 2021-04-09
Filing date: 2021-04-09
Publication date: 2022-07-19
Anticipated expiration: 2041-04-09
Also published as: CN112996189B; CN112996189A

Abstract

The application discloses LED drive control circuit includes: a control terminal for receiving a DC input voltage; the current sampling end receives a current sampling signal; the input detection module is used for acquiring a first voltage signal representing direct-current input voltage and generating a control signal representing an input state according to the first voltage signal and reference voltage; the driving control module is connected with the input detection module, receives the control signal and is used for generating a driving signal according to the control signal; and the first end and the second end of the power switch tube are respectively connected with the control end and the current sampling end, the control end of the power switch tube is connected with the output end of the drive control module and receives a drive signal, and the drive signal is used for controlling the on-off of the power switch tube. The application also discloses an LED driving device, the detection of the input state is realized by multiplexing the existing pins of the LED driving control circuit, the divider resistance for detecting the peripheral direct current input voltage is reduced, and the pins for independently detecting the direct current input voltage are reduced.

Description

LED Driving device and driving control circuit thereof

Technical Field

The invention relates to the technical field of power electronics, in particular to an LED driving device and a driving control circuit thereof.

Background

With the wide application of the LED driving circuit, the LED lamps are available in markets, offices and furniture at present. In many application scenarios, the LED driving circuit needs to be added to detect the dc input voltage, so that the LED driving circuit can be more reasonably applied. For example, the current dimming light bulb is turned on in sections, that is, the brightness of the light bulb changes next time the wall switch is turned on or off until the user is satisfied.

There are also some UPS lighting sources that also need to sense the dc input voltage for further action.

At present, an input detection circuit of an LED driving circuit detects a dc input voltage through resistor voltage division, and usually one pin of the driving control circuit needs to be added, however, the addition of the pin is not favorable for integration, and peripheral devices of the driving control circuit can also be added.

Disclosure of Invention

In order to solve the above technical problem, the present invention provides an LED driving apparatus and a driving control circuit thereof, which can multiplex the existing pins of the driving control circuit to realize detection of a dc input voltage.

According to the present invention, there is provided an LED driving control circuit comprising: a control terminal for receiving a DC input voltage; the current sampling end receives a current sampling signal; the input detection module is used for acquiring a first voltage signal representing direct-current input voltage from one of the control end and the current sampling end and generating a control signal representing an input state according to the first voltage signal and reference voltage; the driving control module is connected with the input detection module, receives the control signal and is used for generating a driving signal according to the control signal; and the first end and the second end of the power switch tube are respectively connected with the control end and the current sampling end, the control end of the power switch tube is connected with the output end of the drive control module and receives the drive signal, and the drive signal is used for controlling the on-off of the power switch tube.

Preferably, the LED driving control circuit further includes: and the voltage feedback end receives a voltage feedback signal representing the output voltage.

Preferably, the input detection module obtains the first voltage signal from one of the control terminal, the current sampling terminal and the voltage feedback terminal.

Preferably, the input detection module multiplexes the control terminal to obtain a first voltage signal representing a dc input voltage.

Preferably, the input detection module is connected to the control terminal, the control terminal receives a dc input voltage, the first voltage signal is a voltage signal between the control terminal and a ground terminal, and the input detection module generates the control signal according to the voltage signal between the control terminal and the ground terminal.

Preferably, the input detection module includes: the conversion unit is used for receiving a first voltage signal and converting the first voltage signal into a second voltage signal; a comparator for comparing the second voltage signal with the reference voltage and outputting a comparison signal; and the time detection unit is used for detecting the effective level maintaining time of the comparison signal and generating the control signal representing the state of the direct current input voltage according to the effective level maintaining time of the comparison signal and preset time.

Preferably, the conversion unit includes a clamp circuit, a transistor, and a fifth resistor, wherein the clamp circuit provides a clamp voltage; the first end of the transistor is connected with the control end, the second end of the transistor is connected with a ground end GND through the fifth resistor, and the control end of the transistor receives the clamping voltage; the first end of the transistor is used as the input end of the conversion unit to receive the first voltage signal, and the second end of the transistor is used as the output end of the conversion unit to output the second voltage signal.

Preferably, when the dc input voltage is greater than a difference between the clamp voltage and a threshold voltage of the transistor, the value of the second voltage signal is the difference between the clamp voltage and the threshold voltage; when the DC input voltage is smaller than the difference between the clamping voltage and the threshold voltage of the transistor, the value of the second voltage signal is the voltage between the control end and the grounding end.

Preferably, the input detection module further comprises: and the filtering unit is positioned between the converting unit and the comparator and is used for filtering the second voltage signal.

Preferably, when the second voltage signal is greater than the reference voltage, the comparison signal is at a high level, and the comparison signal is invalid; when the second voltage signal is less than the reference voltage, the comparison signal is at a low level and is valid.

Preferably, the input detection module multiplexes the current sampling terminal to obtain a first voltage signal representing a dc input voltage.

Preferably, the input detection module is connected to the current sampling terminal, the current sampling terminal receives the current sampling signal, the first voltage signal is the current sampling signal, and the input detection module generates the control signal according to the current sampling signal.

Preferably, the input detection module multiplexes the current feedback terminal to obtain a first voltage signal representing a dc input voltage.

Preferably, the input detection module is connected to the voltage feedback terminal, the voltage feedback terminal receives the voltage feedback signal, the first voltage signal is the voltage feedback signal, and the input detection module generates the control signal according to the voltage feedback signal.

Preferably, the input detection module includes: a comparator for comparing the first voltage signal with the reference voltage and outputting a comparison signal; and the time detection unit is used for detecting the effective level maintaining time of the comparison signal and generating the control signal representing the state of the direct current input voltage according to the effective level maintaining time of the comparison signal and preset time.

Preferably, the input detection module further comprises: and the filtering unit is connected between the first voltage signal and the comparator and is used for filtering the first voltage signal.

Preferably, when the first voltage signal is greater than the reference voltage, the comparison signal is at a high level; when the first voltage signal is less than the reference voltage, the comparison signal is at a low level.

Preferably, the active level of the comparison signal is a low level; when the effective level maintaining time of the comparison signal reaches the preset time, the control signal is a high level and represents that the direct-current input voltage is low; and when the comparison signal is at a high level, the control signal is at a low level, and the direct current input voltage is represented to be high.

Preferably, the LED driving control circuit is not separately provided with an input voltage detection terminal only for dc input voltage detection.

According to another aspect of the present invention, there is provided an LED driving apparatus including: a rectifier bridge circuit for rectifying an alternating input voltage to obtain a direct input voltage; the LED driving control circuit is connected with the rectifier bridge circuit; the power conversion circuit is connected with the LED drive control circuit; the LED driving control circuit controls the power conversion circuit to convert the direct current input voltage into a direct current output signal.

Preferably, the LED driving control circuit obtains a first voltage signal representing the dc input voltage from one of the control terminal, the current sampling terminal and the voltage feedback terminal.

Preferably, the LED driving apparatus further includes: a switch connected between the AC input voltage and the rectifier bridge circuit.

Preferably, when the control signal indicates that the dc input voltage is low, the switch is characterized to be turned off; and when the control signal indicates that the direct current input voltage is high, indicating that the switch is closed. The beneficial effects of the invention are: according to the LED driving device and the control circuit thereof, a pin which is specially used for detecting direct-current input voltage is not required to be added, a first voltage signal representing the direct-current input voltage is directly obtained through the existing pin of the multiplexing control circuit, a control signal representing an input state is generated according to the first voltage signal, and the conduction time of a power switch tube is adjusted according to the control signal, so that the current of a load is adjusted. The LED drive control circuit comprises an input detection circuit, can be integrated in a chip, realizes the detection of an input state, does not increase any pin of the chip, can multiplex the existing pin of the chip, and compared with the prior art, reduces the divider resistance for detecting the direct current input voltage on the periphery of the chip, and simultaneously reduces the chip pin for independently detecting the direct current input voltage.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings.

Fig. 1 shows a circuit diagram of a prior art LED driving apparatus;

fig. 2 illustrates a circuit diagram of an LED driving apparatus provided according to an embodiment of the present invention; fig. 3 shows a circuit diagram of an input detection module provided according to a first embodiment of the invention;

fig. 4 illustrates a waveform diagram of an LED driving apparatus provided in accordance with a first embodiment of the present invention;

fig. 5 shows a circuit diagram of an input detection module provided according to a second embodiment of the invention;

fig. 6 illustrates a waveform diagram of an LED driving apparatus provided in accordance with a second embodiment of the present invention;

fig. 7 shows a circuit diagram of an input detection module provided according to a third embodiment of the present invention;

fig. 8 illustrates a waveform diagram of an LED driving apparatus provided in accordance with a third embodiment of the present invention.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully hereinafter with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. The present invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

The present invention will be described in detail below with reference to the accompanying drawings.

Fig. 1 shows a circuit diagram of a related art LED driving apparatus. Referring to fig. 1, the LED driving apparatus includes a rectifier bridge circuit 110, a driving control circuit 120, a power conversion circuit 130, an input detection circuit 150, and a load 140.

The input terminal of the rectifier bridge circuit 110 receives the ac input voltage Vac, and the output terminal of the rectifier bridge circuit 110 is connected to the input capacitor Cin. The ac input voltage Vac is rectified by the rectifier bridge circuit 110 to output a dc input voltage Vbus. The dc input voltage Vbus is a sinusoidal half-wave signal. A switch K is further disposed between the input terminal of the rectifier bridge circuit 110 and the ac input voltage Vac, and is used to control whether the input terminal of the rectifier bridge circuit 110 is connected to the ac input voltage Vac.

The driving control circuit 120 includes a built-in power switch M0 (not shown), a voltage feedback terminal FB, a current sampling terminal CS, a control terminal DRAIN, a power supply terminal VCC, an input voltage detection terminal Vin, and a ground terminal GND. The power switch tube M0 is connected between the control terminal DRAIN and the current sampling terminal CS. The power supply terminal Vcc is grounded via the first capacitor C1.

The power conversion circuit 130 comprises a freewheeling diode D0, an inductor L0, an output capacitor Cout, a sampling resistor Rcs, a third resistor R3 and a fourth resistor R4, wherein a first end of the inductor L0 is connected with a positive end LED + of the output voltage Vout, and a second end of the inductor L0 is grounded; the cathode of the freewheeling diode D0 is connected to the second terminal of the inductor L0 via the sampling resistor Rcs; the output capacitor Cout is connected between the positive terminal LED + and the negative terminal LED-of the output voltage Vout. The third resistor R3 and the fourth resistor R4 are connected in series between the first terminal and the second terminal of the inductor L0, and a node between the third resistor R3 and the fourth resistor R4 outputs a voltage feedback signal representing the output voltage Vout to the voltage feedback terminal FB of the driving control circuit 120. A node between the freewheel diode D0 and the sampling resistor Rcs is connected to the current sampling terminal CS of the drive control circuit 120.

The input detection circuit 150 includes a first resistor R1 and a second resistor R2, wherein the first resistor R1 and the second resistor R2 are connected in series between the positive output terminal of the rectifier bridge circuit 110 and the ground terminal GND, and the node between the first resistor R1 and the second resistor R2 outputs the input detection voltage Vsns and supplies the input detection voltage to the input voltage detection terminal Vin of the driving control circuit 120.

The load 140 is connected between the positive side LED + and the negative side LED-of the output voltage Vout.

In the prior art, an input detection circuit of an LED driving device detects an input voltage through resistor voltage division, and usually a pin of a driving control circuit needs to be added, however, the addition of the pin is not favorable for integration, and peripheral devices of the driving control circuit can also be added.

Fig. 2 shows a circuit diagram of an LED driving apparatus provided according to an embodiment of the present invention. As shown in fig. 2, the LED driving control circuit 220 includes an input detection module 221, a driving control module 222 and a power switch M0, wherein the LED driving control circuit 220 includes a voltage feedback terminal FB, a current sampling terminal CS, a control terminal DRAIN, a power terminal VCC and a ground terminal GND.

The input detection module 221 is connected to any one of the control terminal DRAIN, the current sampling terminal CS, and the voltage feedback terminal FB, receives a first voltage signal Vx representing a direct-current input voltage Vbus, and is configured to generate a control signal Ctrl representing an input state according to the first voltage signal Vx.

In this embodiment, the control terminal DRAIN is connected to the positive output terminal of the rectifier bridge circuit 110, and receives the dc input voltage Vbus.

When the input detection module 221 is connected to the control terminal DRAIN, the first voltage signal Vx is a voltage signal between the control terminal DRAIN and the ground terminal GND, the voltage signal between the control terminal DRAIN and the ground terminal GND is a high-frequency switching signal, and the reference voltage Vref is a first reference voltage Vref 1.

When the input detection module 221 is connected to the current sampling terminal CS, the first voltage signal Vx is a current sampling signal VCS representing a current flowing through the power switching tube M0, meanwhile, the current sampling signal VCS may represent an ac input voltage Vac, the reference voltage Vref is a second reference voltage Vref2, and the current sampling signal VCS may be used for constant current control of a system at the same time.

When the input detection module 221 is connected to the voltage feedback terminal FB, the first voltage signal Vx is a voltage feedback signal VFB representing the output voltage, the voltage feedback signal VFB can be used for detecting zero crossings of the output voltage and the inductor current of the system at the same time, and the reference voltage Vref is a third reference voltage Vref 3.

The driving control module 222 generates a driving signal to control the power switch M0 to turn on and off according to the control signal Ctrl that represents the input state, so as to adjust the current supplied to the load 240.

According to the LED drive control circuit provided by the embodiment of the invention, a first voltage signal representing input voltage is directly obtained by multiplexing the existing pin without adding a separate input state detection pin, a control signal is generated according to the first voltage signal, and the conduction time of the power switch tube is adjusted according to the control signal, so that the current of a load is adjusted.

Fig. 3 shows a circuit diagram of an input detection module according to a first embodiment of the present invention, as shown in fig. 3, an input end of the input detection module 121 is connected to a control terminal DRAIN, a first voltage signal Vx is a voltage signal Vd between the control terminal DRAIN and a ground terminal GND, and a reference voltage Vref is a first reference voltage Vref 1.

Referring to fig. 3, the input detection module 221 includes a filtering unit 223, a comparator 224, a time detection unit 225, and a conversion unit 226.

The conversion unit 226 is connected to the control terminal DRAIN, and is configured to receive the first voltage signal Vx and convert the first voltage signal Vx into a second voltage signal Vk.

In the present embodiment, the converting unit 226 includes a clamping circuit 227, a transistor Q1, and a fifth resistor R5, wherein a first terminal of the transistor Q1 is connected to the control terminal DRAIN as an input terminal of the converting unit 226, and receives the first voltage signal Vx, a second terminal of the transistor Q1 is connected to the ground terminal GND via the fifth resistor R5, and a control terminal of the transistor Q1 is connected to the clamping circuit 227. The second terminal of the transistor Q1 outputs the second voltage signal Vk as the output terminal of the converting unit 226, and the fifth resistor R5 is used for stabilizing the second voltage signal Vk.

In this embodiment, the clamp 227 may be an active clamp or a passive zener clamp. The transistor Q1 may be an NMOS transistor or an NPN transistor. The clamping voltage output by the clamping circuit 227 is used to clamp the second voltage signal Vk to a low voltage.

Referring to fig. 4, the dc input voltage Vbus decreases, and the voltage signal Vd between the control terminal DRAIN and the ground terminal GND also decreases slowly, when the first voltage signal Vx = Vd. When the direct-current input voltage Vbus is greater than Vg-Vth, namely the first voltage signal Vx is greater than Vg-Vth, the second voltage signal Vk = Vg-Vth, namely the second voltage signal Vk is clamped to Vg-Vth, wherein Vg is a clamping voltage output by the clamping circuit 127, Vth is a threshold voltage of the transistor Q1, and when the direct-current input voltage Vbus is less than or equal to Vg-Vth, namely the first voltage signal Vx is less than or equal to Vg-Vth, the second voltage signal Vk = Vx = Vbus.

When the transistor Q1 is an NMOS transistor, the control terminal of the transistor Q1 is a gate, the first terminal is a drain, and the second terminal is a source. When the transistor Q1 is a transistor, the control terminal of the transistor Q1 is a base, the first terminal is a collector, and the second terminal is an emitter.

The filtering unit 223 is connected to an output of the converting unit 226, and receives the second voltage signal Vk for filtering the second voltage signal Vk.

In this embodiment, the filtering unit 223 includes a sixth resistor R6 and a second capacitor C2, a first end of the sixth resistor R6 receives the first voltage signal Vx, a second end of the sixth resistor R6 is connected to a first end of the second capacitor C2, a second end of the second capacitor C2 is connected to the ground GND, and a node between the sixth resistor R6 and the second capacitor C2 is connected to the non-inverting input terminal of the comparator 224.

The comparator 224 outputs a comparison signal Pulse according to a comparison result of the filtered second voltage signal Vk and the reference voltage Vref.

In the present embodiment, the inverting input terminal of the comparator 224 receives the first reference voltage Vref1, the non-inverting input terminal receives the filtered second voltage signal Vk, and the output terminal outputs the comparison signal Pulse. In other embodiments, the comparator 224 has an inverting input that receives the filtered second voltage signal Vk and a non-inverting input that receives the first reference voltage Vref 1.

The time detecting unit 225 is configured to detect the active level maintaining time TL of the comparison signal Pulse, and generate the control signal Ctrl according to a comparison result between the active level maintaining time TL of the comparison signal Pulse and the preset time T1.

In this embodiment, the active level is a low level. In other embodiments, the active level is high when the comparator 224 is reverse connected.

Referring to fig. 4, the comparison signal Pulse is at a high level when the filtered second voltage signal Vk is greater than the first reference voltage Vref1, and at a low level when the filtered second voltage signal Vk is less than the Vref 1. The time detection unit 225 detects the active level holding time TL of the comparison signal Pulse, and when the comparison signal Pulse is at a high level, the control signal Ctrl is at a low level. When the effective level maintaining time TL of the comparison signal Pulse is less than the preset time T1, the control signal Ctrl is at a low level; when the active level maintaining time TL of the comparison signal Pulse reaches the preset time T1, the control signal Ctrl is at a high level.

When the dc input voltage Vbus of the LED driving apparatus becomes low, the voltage at the first end of the transistor Q1 is always low, the active level maintaining time TL of the comparison signal Pulse output by the comparator 224 exceeds the preset time T1, and the control signal Ctrl jumps from low level to high level, which indicates that the ac input voltage Vac of the LED driving apparatus is low; when the dc input voltage Vbus of the LED driving apparatus is relatively high, the voltage at the first end of the transistor Q1 is always high, the active level maintaining time TL of the comparison signal Pulse does not reach the preset time T1, and the control signal Ctrl is at a low level, which indicates that the ac input voltage Vac of the LED driving apparatus is relatively high.

The input detection module 221 detects the level of the ac input voltage Vac, so as to adjust the output current, for example, when the value of the ac input voltage Vac is high, the output current becomes large; when the value of the ac input voltage Vac is low, the output current is small or 0.

When the ac input voltage Vac is the ac input of the utility power, the on/off operation of the switch K in front of the rectifier bridge circuit 210 may be detected, and when the value of the ac input voltage Vac is high, the switch K is determined to be on; when the value of the alternating current input voltage Vac is low, judging that the switch K is turned off; when the ac input voltage Vac is an emergency power supply device, the output voltage of the emergency power supply device can be detected.

The input detection module provided by the first embodiment of the invention acquires the first voltage signal representing the input voltage through the control end and generates the control signal representing the input state according to the first voltage signal.

Fig. 5 shows a circuit diagram of an input detection module provided in a second embodiment of the present invention. Compared with the first embodiment, the input detection module 221 of the second embodiment of the present invention omits the conversion unit 226; the input terminal of the input detection module 221 is directly connected to the current sampling terminal CS, and the first voltage signal Vx is a current sampling signal VCS representing a current flowing through the switching tube M0. The reference voltage Vref is a second reference voltage Vref 2.

In this embodiment, the filtering unit 223 filters the first voltage signal Vx. A first end of the sixth resistor R6 receives the first voltage signal Vx, a second end of the sixth resistor R6 is connected to a first end of the second capacitor C2, a second end of the second capacitor C2 is connected to the ground GND, and a node between the sixth resistor R6 and the second capacitor C2 is connected to the non-inverting input terminal of the comparator 224.

In the present embodiment, the current sampling signal Vcs = Rcs (Vbus-Vout) × Ton/L, and Ton is the on-time of the power switch M0. Referring to fig. 6, when the dc input voltage Vbus continuously decreases, the peak voltage of the current sampling signal VCS also decreases, when VCS is less than Vref2, the comparison signal Pulse is at a low level, and when the active level maintaining time TL of the comparison signal Pulse reaches the preset time T1, that is, when the low level maintaining time TL of the comparison signal Pulse reaches the preset time T1, the control signal Ctrl jumps from a low level to a high level, which indicates that the ac input voltage Vac of the LED driving apparatus is low.

The input detection module provided by the second embodiment of the invention acquires the current sampling signal representing the input voltage through the current sampling terminal and generates the control signal representing the input state according to the current sampling signal.

Fig. 7 shows a circuit diagram of an input detection module provided by a third embodiment of the present invention. Compared with the first embodiment, the input detection module 221 according to the third embodiment of the present invention omits the conversion unit 226, the input end of the input detection module 221 is directly connected to the voltage feedback end FB, and the first voltage signal Vx is the voltage feedback signal VFB representing the output voltage. The reference voltage Vref is a third reference voltage Vref 3.

Referring to fig. 8, the voltage feedback signal VFB becomes lower and lower as the dc input voltage Vbus decreases in voltage. When the filtered voltage feedback signal VFB is smaller than the third reference voltage Vref3, the comparison signal Pulse is at a low level, and when the active level maintaining time TL of the comparison signal Pulse reaches the preset time T1, that is, when the low level maintaining time of the comparison signal Pulse reaches the preset time T1, the control signal Ctrl jumps from a low level to a high level, which indicates that the ac input voltage Vac of the LED driving apparatus is very low.

The input detection module provided by the third embodiment of the present invention obtains the voltage feedback signal representing the input voltage through the voltage feedback terminal, and generates the control signal representing the input state according to the voltage feedback signal, and the input detection module can be integrated in the LED driving control circuit, and does not need to add a new pin, thereby reducing the number of peripheral devices of the LED driving control circuit.

It should be noted that in the description of the present invention, it is to be understood that the terms "upper", "lower", "inner", and the like, indicate orientation or positional relationship, are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the referenced components or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present invention.

In addition, in this document, the terms "include", "include" or any other variation thereof are intended to cover a non-exclusive inclusion, so that a process, a method, an article or an apparatus including a series of elements includes not only those elements but also other elements not explicitly listed or inherent to such process, method, article or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

Finally, it should be noted that: it should be understood that the above examples are only for clearly illustrating the present invention and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of the invention may be made without departing from the scope of the invention.

Claims

1. An LED drive control circuit, comprising:

the control end of the LED drive control circuit receives direct current input voltage;

the current sampling end receives a current sampling signal;

the input detection module is used for acquiring a first voltage signal representing direct-current input voltage from one of a control end of the LED drive control circuit and the current sampling end and generating a control signal representing an input state according to the first voltage signal and reference voltage;

the driving control module is connected with the input detection module, receives the control signal and is used for generating a driving signal according to the control signal;

the power switch tube, the first end and the second end of power switch tube respectively with LED drive control circuit's control end with the current sampling end is connected, the control end of power switch tube with the output of drive control module links to each other, receives drive signal, drive signal is used for controlling switching on and turn-off of power switch tube.

2. The LED driving control circuit according to claim 1, further comprising:

and the voltage feedback end receives a voltage feedback signal representing the output voltage.

3. The LED driving control circuit of claim 2, wherein the input detection module obtains the first voltage signal from the voltage feedback terminal.

4. The LED driving control circuit according to claim 3, wherein the input detection module multiplexes the control terminal of the LED driving control circuit to obtain the first voltage signal indicative of the DC input voltage.

5. The LED driving control circuit according to claim 4, wherein the input detection module is connected to a control terminal of the LED driving control circuit, the control terminal of the LED driving control circuit receives the DC input voltage, the first voltage signal is a voltage signal between the control terminal and a ground terminal of the LED driving control circuit, and the input detection module generates the control signal according to the voltage signal between the control terminal and the ground terminal of the LED driving control circuit.

6. The LED driving control circuit according to claim 5, wherein the input detection module comprises:

the conversion unit is used for receiving the first voltage signal and converting the first voltage signal into a second voltage signal;

a comparator for comparing the second voltage signal with the reference voltage and outputting a comparison signal;

and the time detection unit is used for detecting the effective level maintaining time of the comparison signal and generating the control signal representing the input state according to the effective level maintaining time of the comparison signal and preset time.

7. The LED driving control circuit according to claim 6, wherein the converting unit comprises a clamping circuit, a transistor and a fifth resistor, wherein the clamping circuit provides a clamping voltage;

the first end of the transistor is connected with the control end of the LED drive control circuit, the second end of the transistor is connected with the ground end through the fifth resistor, and the control end of the transistor receives the clamping voltage;

the first end of the transistor is used as the input end of the conversion unit to receive the first voltage signal, and the second end of the transistor is used as the output end of the conversion unit to output the second voltage signal.

8. The LED drive control circuit of claim 7 wherein the value of the second voltage signal is the difference between the clamped voltage and the threshold voltage when the DC input voltage is greater than the difference between the clamped voltage and the threshold voltage of the transistor; when the DC input voltage is smaller than the difference between the clamping voltage and the threshold voltage of the transistor, the value of the second voltage signal is the first voltage signal.

9. The LED driving control circuit according to claim 6, wherein when the second voltage signal is greater than the reference voltage, the comparison signal is high, and the comparison signal is inactive; when the second voltage signal is less than the reference voltage, the comparison signal is at a low level and is valid.

10. The LED driving control circuit according to claim 6, wherein when the active level maintaining time of the comparison signal reaches a preset time, the control signal is at a high level, indicating that the DC input voltage is low; when the control signal is at a low level, the direct current input voltage is characterized to be high.

11. The LED driving control circuit according to claim 6, wherein the input detection module further comprises:

and the filtering unit is positioned between the converting unit and the comparator and is used for filtering the second voltage signal.

12. The LED driving control circuit of claim 3, wherein the input detection module multiplexes the current sampling terminal to obtain the first voltage signal representative of the DC input voltage.

13. The LED driving control circuit of claim 12, wherein the input detection module is connected to the current sampling terminal, the current sampling terminal receives the current sampling signal, the first voltage signal is the current sampling signal, the current sampling signal is indicative of a current flowing through the power switch, and the input detection module generates the control signal according to the current sampling signal.

14. The LED driving control circuit of claim 3, wherein the input detection module multiplexes the voltage feedback terminal to obtain the first voltage signal representative of the DC input voltage.

15. The LED driving control circuit of claim 14, wherein the input detection module is connected to the voltage feedback terminal, the voltage feedback terminal receives the voltage feedback signal, the first voltage signal is the voltage feedback signal, and the input detection module generates the control signal according to the voltage feedback signal.

16. The LED driving control circuit according to claim 13 or 15, wherein the input detection module comprises:

a comparator for comparing the first voltage signal with the reference voltage and outputting a comparison signal;

17. The LED driving control circuit of claim 16, wherein when the first voltage signal is greater than the reference voltage, the comparison signal is high and the comparison signal is inactive; when the first voltage signal is less than the reference voltage, the comparison signal is at a low level and is valid.

18. The LED driving control circuit of claim 17, wherein when the active level of the comparison signal is maintained for a predetermined time, the control signal is at a high level indicating that the dc input voltage is low; when the control signal is at a low level, the direct current input voltage is characterized to be high.

19. The LED drive control circuit of claim 16, further comprising:

and the filtering unit is connected between the first voltage signal and the comparator and is used for filtering the first voltage signal.

20. The LED driving control circuit according to claim 1, wherein the LED driving control circuit is not separately provided with an input voltage detection terminal only for dc input voltage detection.

21. An LED driving apparatus, comprising:

a rectifier bridge circuit for rectifying an ac input voltage to obtain a dc input voltage;

the LED drive control circuit of any of claims 1-20, connected to the rectifier bridge circuit;

the power conversion circuit is connected with the LED drive control circuit;

the LED driving control circuit controls the power conversion circuit to convert the direct current input voltage into a direct current output signal.

22. The LED driving apparatus according to claim 21, wherein the driving control circuit obtains the first voltage signal indicative of the dc input voltage from one of a control terminal, a current sampling terminal and a voltage feedback terminal of the LED driving control circuit.

23. The LED driving apparatus according to claim 21, further comprising:

a switch connected between the AC input voltage and the rectifier bridge circuit.

24. The LED driving apparatus according to claim 23, wherein the switch is characterized to be off when the control signal is indicative of the dc input voltage being low; and when the control signal indicates that the direct current input voltage is high, indicating that the switch is closed.