CN115226269A

CN115226269A - Single-path constant current drive circuit and camera device

Info

Publication number: CN115226269A
Application number: CN202210980464.8A
Authority: CN
Inventors: 许治豹; 罗翔; 黄长辉; 李鹏飞
Original assignee: Tonly Electronics Holdings Ltd
Current assignee: Tonly Electronics Holdings Ltd
Priority date: 2022-08-16
Filing date: 2022-08-16
Publication date: 2022-10-21

Abstract

The embodiment of the application provides a one-way constant current drive circuit and camera device, wherein, the one-way constant current drive circuit for drive the different first way LED lamp of luminescent color and second way LED lamp, the one-way constant current drive circuit includes: the switching circuit comprises a first branch and a second branch which are arranged in parallel, the first branch is used for being connected with the first path of LED lamps, and the second branch is used for being connected with the second path of LED lamps; the driving circuit is connected with the switching circuit; when the driving circuit and the switching circuit receive the first signal, the driving circuit outputs a first voltage signal, the first branch of the switching circuit is switched on, and the second branch of the switching circuit is switched off, so that the first voltage signal drives the first LED lamp; when the driving circuit and the switching circuit receive the second signal, the driving circuit outputs a second voltage signal, the second branch of the switching circuit is switched on, and the first branch is switched off, so that the second voltage signal drives the second LED lamp, and the voltage values of the first voltage signal and the second voltage signal are different.

Description

Single-path constant current drive circuit and camera device

Technical Field

The present disclosure relates to the field of image capture, and particularly to a one-way constant current driving circuit and an image capture apparatus.

Background

In lighting and backlighting applications, multiple LED lamps, each comprising one or more LED lamps connected in series, are often used in series or in parallel. Due to the light emitting characteristics of the LED, the light emitting intensity of the LED is determined by the current flowing through the LED.

The current of each path of LED lamp is generally independently adjusted by the existing LED constant current driving circuit, or one path of constant current driving circuit drives a plurality of paths of same LEDs to be connected in series and in parallel, the stable luminous intensity is maintained by controlling the constant current of each path of LED, if two paths of LEDs with different colors, such as an infrared lamp and a white light lamp, need to be driven, two paths of constant current IC driving circuits are needed, the circuit of the constant current driving circuit is relatively complex, and the cost is increased.

Disclosure of Invention

The embodiment of the application provides a one-way constant current driving circuit and a camera device, which can improve the situation that the existing constant current driving circuit has complex circuits.

The embodiment of the application provides a single-circuit constant current drive circuit, single-circuit constant current drive circuit is used for driving the different first way LED lamp of luminescent color and second way LED lamp, single-circuit constant current drive circuit includes:

the switching circuit comprises a first branch circuit and a second branch circuit which are arranged in parallel, the first branch circuit is used for being connected with the first path of LED lamp, and the second branch circuit is used for being connected with the second path of LED lamp;

a drive circuit connected to the switching circuit;

when the driving circuit and the switching circuit receive a first signal, the driving circuit outputs a first voltage signal, the first branch of the switching circuit is switched on, and the second branch of the switching circuit is switched off, so that the first voltage signal drives the first LED lamp;

when the driving circuit and the switching circuit receive a second signal, the driving circuit outputs a second voltage signal, the second branch of the switching circuit is switched on, and the first branch is switched off, so that the second voltage signal drives the second path of LED lamp, and the voltage values of the first voltage signal and the second voltage signal are different.

Optionally, the driving circuit includes a first signal input terminal, a first resistor, a first switching tube, and an output terminal, where the first resistor and the first switching tube are connected in parallel;

when the first signal input end receives the first signal, the first switch tube and the first resistor are both conducted, and the output end outputs the first voltage signal;

when the first signal input end receives the second signal, the first resistor is switched on, the first switch tube is switched off, and the output end outputs the second voltage signal.

Optionally, the control end of the first switch tube is connected to the first signal input end, the first end of the first switch tube is connected to the first end of the first resistor, the second end of the first switch tube is connected to the output end, the first end of the first resistor is grounded, and the second end of the first resistor is connected to the output end.

Optionally, the driving circuit further includes a resistor unit, a first end of the resistor unit is connected to the second end of the first switch tube, a second end of the resistor unit is connected to the output end, and the resistor unit includes a plurality of resistors connected in parallel.

Optionally, the single-path constant current driving circuit further includes a power interface;

the first branch circuit comprises a second switching tube, and the control end of the second switching tube is connected with the first signal input end;

the second branch comprises a third switching tube and a fourth switching tube, the control end of the third switching tube is connected with the first signal input end, the first end of the third switching tube is connected with the control end of the fourth switching tube, the first end of the third switching tube is also used for being connected with the power interface, the second end of the third switching tube is grounded, and the first end of the fourth switching tube is connected with the first end of the second switching tube;

when the first signal input end receives the first signal, the second switching tube and the third switching tube are conducted, and the fourth switching tube is cut off to drive the first path of LED lamp;

when the first signal input end receives the second signal, the second switch tube and the third switch tube are cut off, and the fourth switch tube is conducted to drive the second path of LED lamps.

Optionally, the output includes first power output and second power output, first branch road still includes the second resistance, the control end of second switch tube is connected first signal input part, the second end of second switch tube is connected first power output, the first end of second switch tube is connected the second power output, the one end of second resistance is connected the control end of second switch tube, the other end ground connection of second resistance.

Optionally, the second branch circuit further includes a third resistor, the control end of the third switch tube is connected to the first signal input end, the first end of the third switch tube is connected to the control end of the fourth switch tube, the second end of the third switch tube is grounded, the second end of the fourth switch tube is connected to the first power output end, the first end of the fourth switch tube is connected to the second power output end, the first end of the third resistor is connected to the second end of the third switch tube, and the second end of the third resistor is grounded.

Optionally, the single-path constant current driving circuit further includes a constant current driving chip and an energy storage inductor;

the power interface is connected with a first end of the energy storage inductor, a second end of the energy storage inductor is connected with the first power output end, a first end of the constant current driving chip is connected with the power interface, a second end of the constant current driving chip is connected with a second end of the energy storage inductor, and a third end of the constant current driving chip is connected with the second power output end.

Optionally, the driving circuit further includes a second signal input end, and the second signal input end is connected to the fourth end of the constant current driving chip;

when the second signal input end receives a third signal, the third end of the constant current driving chip stops outputting a voltage signal;

when the second signal input end receives a fourth signal, a third end of the constant current driving chip outputs a voltage signal, and the third signal is different from the fourth signal.

The embodiment of the application also provides a camera device, which comprises the single-path constant current driving circuit.

The beneficial effect of this application lies in: the single-path constant current driving circuit provided by the embodiment of the application is used for driving a first path of LED lamps and a second path of LED lamps which are different in luminous color, and comprises a driving circuit and a switching circuit, when the driving circuit and the switching circuit receive a first signal, the driving circuit outputs a first voltage signal, a first branch of the switching circuit is conducted, a second branch of the switching circuit is disconnected, so that the first voltage signal drives the first path of LED lamps, when the driving circuit and the switching circuit receive a second signal, the driving circuit outputs a second voltage signal, a second branch of the switching circuit is conducted, and the first branch is disconnected, so that the second voltage signal drives the second path of LED lamps, and the voltage values of the first voltage signal and the second voltage signal are different.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings used in the description of the embodiments will be briefly introduced below. It is obvious that the drawings in the following description are only some embodiments of the application, and that for a person skilled in the art, other drawings can also be derived from them without inventive effort.

For a more complete understanding of the present application and its advantages, reference is now made to the following descriptions taken in conjunction with the accompanying drawings. Wherein like reference numerals refer to like parts in the following description.

Fig. 1 is a schematic structural diagram of a single-channel constant current driving circuit provided in an embodiment of the present application.

Fig. 2 is a circuit schematic diagram of a driving circuit in the single-path constant current driving circuit shown in fig. 1.

Fig. 3 is a schematic structural diagram of a switching circuit in the single-channel constant current driving circuit shown in fig. 1.

Fig. 4 is a circuit schematic diagram of a switching circuit in the one-way constant current driving circuit shown in fig. 1.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In the description of the present application, it is to be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated in a particular manner, and are not to be construed as limiting the present application. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

In a traditional constant current driving circuit, one path of constant current IC drives one path or multiple paths of same LEDs to be connected in series and in parallel, and the maximum current cannot be changed after a load resistor is set. In addition, the constant current IC cannot drive the infrared lamp and the white light lamp at the same time because the voltage drops of different lamp beads are different. If two paths of LEDs with different colors, such as an infrared lamp and a white light lamp, need to be driven, two paths of constant-current IC drive circuits need to be used, so that the circuits of the constant-current drive circuits are complex, and the cost is increased.

Therefore, in order to solve the above problems, the present application proposes a one-way constant current drive circuit and an image pickup apparatus. The present application will be further described with reference to the accompanying drawings and embodiments.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a single-channel constant current driving circuit according to an embodiment of the present disclosure. The embodiment of the application provides a single-path constant current driving circuit 100, which is used for driving a first path of LED lamps 200 and a second path of LED lamps 300 with different specifications, wherein the light emitting color of the first path of LED lamps 200 is different from the light emitting color of the second path of LED lamps 300. The single-path constant current driving circuit 100 comprises a driving circuit 10 and a switching circuit 20, the switching circuit 20 comprises a first branch 210 and a second branch 220 which are arranged in parallel, the first branch 210 is used for being connected with a first path of LED lamp 200, the driving circuit 10 is connected with the switching circuit 20, when the driving circuit 10 and the switching circuit 20 receive a first signal, the driving circuit 10 outputs a first voltage signal, the first branch 210 of the switching circuit 20 is connected, and the second branch 220 is disconnected, so that the first voltage signal drives the first path of LED lamp 200; when the driving circuit 10 and the switching circuit 20 receive the second signal, the driving circuit 10 outputs a second voltage signal, the second branch 220 of the switching circuit 20 is turned on, and the first branch 210 is turned off, so that the second voltage signal drives the second LED lamp 300, and the voltage values of the first voltage signal and the second voltage signal of the power interface are different. According to the embodiment of the application, the corresponding voltage signals are output by one driving circuit when different signals are received, so that the LED lamps of different branches can be controlled to be on, the driving voltage value in the circuit can be adjusted, the circuit of the constant current driving circuit is simplified, and the cost is saved.

It should be noted that the first path of LED lamp 200 may be a plurality of lamp beads of the same specification connected in series, and the lamp bead of the first path of LED lamp 200 may be an infrared lamp with a single voltage drop of about 1.4V, or may be a white light with a single voltage drop VF of about 3.2V. The second LED lamp 300 may be a plurality of lamp beads of the same specification connected in series, and the lamp beads of the second LED lamp 300 may be infrared lamps with a single voltage drop of about 1.4V, or may be white light with a single voltage drop VF of about 3.2V. The first path of LED lamp 200 and the second path of LED lamp 300 may also be lamp beads of other specifications, which is not specifically limited herein, and only the specification of the first path of LED lamp 200 and the specification of the second path of LED lamp 300 need to be different, in addition, in the embodiment of the present application, the lamp bead of the first path of LED lamp 200 is taken as an infrared lamp, and the lamp bead of the second path of LED lamp 300 is taken as a white lamp for illustration, which should not be construed as a limitation thereto.

Referring to fig. 2, fig. 2 is a circuit diagram of a driving circuit in the single-channel constant current driving circuit shown in fig. 1. The driving circuit 10 includes a first signal input end 120, a second signal input end 110, a first resistor R3, a first switch tube Q3 and an output end 130, wherein the first resistor R3 is connected in parallel with the first switch tube Q3; when the first signal input end 120 receives a first signal, the first switch tube Q3 and the first resistor R3 are both turned on, and the output end 130 outputs a first voltage signal; when the first signal input terminal 120 receives the second signal, the first resistor R3 is turned on, the first switch Q3 is turned off, and the output terminal 130 outputs the second voltage signal.

Illustratively, the output end 130 is respectively connected to the first LED lamp 200 and the second LED lamp 300, wherein when the first signal input end 120 receives a high level signal, the first switch tube Q3 and the first resistor R3 are turned on, and the voltage of the output end 130 is a first voltage. When the first signal input end 120 receives a low level signal, the first resistor R3 is turned on, the first switch Q3 is turned off, the current of the signal output end 130 is a second voltage, and the first voltage is greater than the second voltage. According to the embodiment of the application, the first switch tube Q3 is turned on or off to adjust the voltage output by the output end 130, so that the current at two ends of the first path of LED lamp 200 can be adjusted, or the current at two ends of the second path of LED lamp 300 can be adjusted, thereby realizing PWM dynamic dimming and meeting the brightness requirements of different application scenes.

The connection mode of the driving circuit 10 may be as follows: the control end of the first switch tube Q3 is connected to the first signal input end 120, the first end of the first switch tube Q3 is connected to the first end of the first resistor R3, the second end of the first switch tube Q3 is connected to the output end 130, the first end of the first resistor R3 is grounded, and the second end of the first resistor R3 is connected to the output end 130.

It should be noted that the first switch tube Q3, the second switch tube Q1, the third switch tube Q4, and the fourth switch tube Q2 may be transistors, field effect transistors, or other switches, and are not limited in particular, and in the embodiment of the present application, the first switch tube Q3, the second switch tube Q1, and the fourth switch tube Q2 are field effect transistors, and the third switch tube Q4 is a transistor, but should not be construed as limiting.

In some embodiments, the driving circuit 10 further includes a resistor unit Rx, a first end of the resistor unit Rx is connected to the second end of the first switch Q3, and a second end of the resistor unit Rx is connected to the output terminal 130. Specifically, a first end of the first resistor R3 is connected to the second signal input end 110, a second end of the first resistor R3 is grounded, a first end of the resistor unit Rx is connected to the second signal input end 110, a second end of the resistor unit Rx is connected to a drain of the first switch Q3, a source of the first switch Q3 is grounded, and a gate of the first switch Q3 is connected to the first signal input end 120.

When the first signal input end 120 receives a high level signal, the gate of the first switch tube Q3 is at a high level, so that the first switch tube Q3 is turned on, and further the resistor unit Rx connected in series with the first switch tube Q3 is turned on, that is, the resistor connected in parallel with the first resistor R3 is increased, so that the resistance value after parallel connection is smaller, and further the current value of the first current at the output end 130 is larger.

When the first signal input end 120 receives a low level signal, the gate of the first switch tube Q3 is at a low level, so that the first switch tube Q3 is turned off, and then the resistor unit Rx connected in series with the first switch tube Q3 is turned off, that is, only the first resistor R3 is turned on, so that the resistance value in the circuit is relatively large, and further the current value of the first current at the output end 130 is reduced.

The resistor unit Rx includes a plurality of resistors connected in parallel, and it should be noted that the size of each resistor may be the same or different, and may be specifically designed according to an actual situation, and the number of the resistors in the resistor unit Rx may also be set according to the actual situation, which is not specifically limited herein.

The driving circuit 10 further includes a seventh resistor R7 and an eighth resistor R8, one end of the seventh resistor R7 is connected to the first signal input terminal 120, and the other end of the seventh resistor R7 is connected to the gate of the first switch Q3. One end of the eighth resistor R8 is connected to the gate of the first switch Q3, and the other end of the eighth resistor R8 is grounded.

Referring to fig. 3, fig. 3 is a schematic structural diagram of the switching circuit 20 in the single-channel constant current driving circuit shown in fig. 1. The first branch 210 includes a second switch tube Q1, the second branch 220 includes a fourth switch tube Q2 and a third switch tube Q4, one end of the third switch tube Q4 is connected to the first signal input end 120, a control end of the third switch tube Q4 is connected to a control end of the fourth switch tube Q2, a first end of the fourth switch tube Q2 is connected to a first end of the second switch tube Q1, and a control end of the second switch tube Q1 is connected to the first signal input end 120. When the driving circuit 10 receives the first signal, the second switching tube Q1 is turned on, the third switching tube Q4 is turned on, and the fourth switching tube Q2 is turned off, so that the first LED lamp 200 is turned on, and the second LED lamp 300 is turned off. When the driving circuit 10 receives the second signal, the second switching tube Q1 is turned off, the third switching tube Q4 is turned off, and the fourth switching tube Q2 is turned on, so that the second path of LED lamp 300 and the first path of LED lamp 200 are not turned on. In the embodiment of the application, the second switch tube Q1 is arranged in the first branch 210 connected with the first path of LED lamp 200, the fourth switch tube Q2 and the third switch tube Q4 are arranged in the second branch 220 connected with the second path of LED lamp 300, and when the driving circuit 10 receives a first signal, the second switch tube Q1 is controlled to be turned on, so that the first path of LED lamp 200 is turned on, and the third switch tube Q4 is controlled to be turned on by the first signal, so that the fourth switch tube Q2 is turned off, and therefore the second path of LED lamp 300 is turned off. When the driving circuit 10 receives a second signal, the second switching tube Q1 is controlled to be turned off, so that the first path of LED lamp 200 is not lit, and the third switching tube Q4 is controlled to be turned off by the second signal, so that the fourth switching tube Q2 is turned on, and further the second path of LED lamp 300 is lit. Therefore, the driving circuit 10 in the single-path constant current driving circuit 100 receives the first signal or the second signal, and different paths of LED lamps can be controlled to be on only by switching different signals, so that the circuit of the single-path constant current driving circuit 100 is simplified, and the cost is saved.

It should be noted that, when the second signal input terminal 110 receives the third signal, the third terminal of the constant current driving chip stops outputting the voltage signal, and neither the first LED lamp 200 nor the second LED lamp 300 is turned on. When the second signal input end 110 receives a fourth signal, the third end of the constant current driving chip outputs a voltage signal, and the first LED lamp 200 or the second LED lamp 300 is turned on, where the third signal is different from the fourth signal.

Illustratively, when the second signal input terminal 110 receives a low-level signal, neither the first LED lamp 200 nor the second LED lamp 300 is on. When the second signal input end 110 receives a high level signal and the first signal input end 120 inputs a high level signal, that is, the driving circuit 10 receives a first signal, the first LED lamp 200 is turned on, and the second LED lamp 300 is turned off; when the second signal input terminal 110 receives a high level signal and the first signal input terminal 120 receives a low level signal, the second LED lamp 300 is turned on, and the first LED lamp 200 is not turned on. Receive low level signal through controlling second signal input terminal 110, with control first way LED lamp 200 and second way LED lamp 300 all unlighted, and when second signal input terminal 110 received high level signal, receive high level signal or low level signal through first signal input terminal 120 in order to control first way LED lamp 200 or the lamp of second way LED lamp 300 one of bright, and then can realize that single way constant current drive circuit 100 drives the LED lamp of the different specifications of double-circuit, the circuit structure has been simplified, and then the cost is saved, and the structure volume is compacter, still be favorable to the miniaturization of product.

The high level signal or the low level signal received by the first signal input end 120 and the second signal input end 110 may be input by an external device, or may be input by other local control units, which is not limited specifically herein, and only needs to be able to input the relevant high level signal or low level signal.

Referring to fig. 4, fig. 4 is a circuit diagram of the switching circuit 20 in the single-channel constant current driving circuit shown in fig. 1. The first branch 210 includes a second resistor R1, one end of the second resistor R1 is connected to the first signal input end 120 of the driving circuit 10, the other end of the second resistor R1 is grounded, the gate of the second switch Q1 is connected to the driving circuit 10, the drain of the second switch Q1 is connected to the first power output end 131, the source of the second switch Q1 is connected to the second power output end 132, the first power output end 131 is connected to the anode of the first LED lamp 200, and the second power output end 132 is connected to the cathode of the first LED lamp 200. Its second resistor R1 is used to absorb over-voltage and over-current and plays a role of buffering in its first branch 210.

When the second signal input end 110 receives a high level signal and the first signal input end 120 receives the high level signal, the gate of the second switch tube Q1 is at a high level, and then the second switch tube Q1 can be turned on, so that the anode of the first path of LED lamp 200 and the cathode of the first path of LED lamp 200 are turned on, and then the first path of LED lamp 200 is turned on.

When the second signal input end 110 receives a high level signal and the first signal input end 120 receives a low level signal, the gate of the second switch tube Q1 is at a low level, so that the second switch tube Q1 is turned off, the anode of the first path of LED lamp 200 and the cathode of the first path of LED lamp 200 are turned off, and the first path of LED lamp 200 is turned off.

In some embodiments, the first branch circuit 210 further includes a fourth resistor R4, one end of the fourth resistor R4 is connected to the first signal input end 120, the other end of the fourth resistor R4 is connected to the gate of the second switch Q1, and the fourth resistor R4 is a current-limiting resistor, and is used to limit the current of the first branch circuit 210, so as to prevent the series-connected components from being burned out due to an excessive current. Meanwhile, the fourth resistor R4 can also play a role in voltage division.

The single-path constant current driving circuit further comprises a power interface VSS, the second branch circuit 220 further comprises a third resistor R2, a base of a third switching tube Q4 is connected with the first signal input end 120 of the driving circuit 10, an emitter of the third switching tube Q4 is grounded, a collector of the third switching tube Q4 is connected with a gate of a fourth switching tube Q2, a first end of the third resistor R2 is connected with a collector of the third switching tube Q4, a second end of the third resistor R2 is grounded, the power interface VSS is connected with a first end of the third resistor R2, a drain of the fourth switching tube Q2 is connected with the first power output end 131, a source of the fourth switching tube Q2 is connected with the second power output end 132, the first power output end 131 is connected with an anode of the second path of LED lamps 300, and the second power output end 132 is connected with a cathode of the second path of LED lamps 300.

When the second signal input end 110 receives a high level signal and the first signal input end 120 receives a low level signal, the base of the third switching tube Q4 is at a low level, so that the third switching tube Q4 is not conducted, the power supply interface VSS is grounded after passing through the third resistor R2, so that the gate of the fourth switching tube Q2 is at a high level, and the fourth switching tube Q2 is conducted, so that the anode of the second LED lamp 300 is conducted with the cathode of the second LED lamp 300, and the second LED lamp 300 is turned on.

When the second signal input end 110 receives a high level signal and the first signal input end 120 receives a high level signal, the base of the third switching tube Q4 is at a high level, the third switching tube Q4 is turned on, so that the power interface VSS is grounded after passing through the third switching tube Q4, and further the gate of the fourth switching tube Q2 is at a low level, so that the fourth switching tube Q2 is turned off, and further the anode of the second LED lamp 300 and the cathode of the second LED lamp 300 are not turned on, and thus the second LED lamp 300 is not turned on.

In some embodiments, the second branch circuit 220 further includes a fifth resistor R5 and a sixth resistor R6, one end of the fifth resistor R5 is connected to the first signal input terminal 120, the other end of the fifth resistor R5 is connected to the base of the third switching tube Q4, and the fifth resistor R5 is a current limiting resistor for limiting the current of the second branch circuit 220, so as to prevent the series-connected components from being burned out due to the excessive current. Meanwhile, the fifth resistor R5 can also play a role in voltage division. One end of a sixth resistor R6 is connected with the power interface VSS, the other end of the sixth resistor R6 is connected with a grid electrode of the fourth switching tube Q2, and the sixth resistor R6 is used for overvoltage protection and is used for resisting high voltage which accidentally appears on a line.

The single-circuit constant current driving circuit 100 further comprises a constant current driving chip 40 and an energy storage inductor L, and the output terminal 130 comprises a first power output terminal 131 and a second power output terminal 132; the power interface VSS is connected to the first end of the energy storage inductor L, the second end of the energy storage inductor L is connected to the first power output end 131, the first end of the constant current driving chip 40 is connected to the power interface VSS, the second end of the constant current driving chip 40 is connected to the second end of the energy storage inductor L, the fourth end of the constant current driving chip 40 is connected to the second signal input end 110, the third end of the constant current driving chip 40 is connected to the second power output end 132, the first end of the first resistor R3 is connected to the third end of the constant current driving chip 40, and the fifth end of the constant current driving chip 40 is grounded.

It should be noted that, in some embodiments, the first power output terminal 131 is a positive electrode, and the second power output terminal 132 is a negative electrode.

The driving circuit 10 further includes a ninth resistor R9, a tenth resistor R10 and a third capacitor C3, one end of the ninth resistor R9 is connected to the second signal input terminal 110, the other end of the ninth resistor R9 is connected to the fourth terminal of the constant current driving chip 40, one end of the tenth resistor R10 is connected to the other end of the ninth resistor R9, and the other end of the tenth resistor R10 is grounded. The third capacitor C3 is connected in parallel with the tenth resistor R10.

In some embodiments, the one-way constant current driving circuit 100 further includes a fourth capacitor C4 and a fifth capacitor C5, where the fourth capacitor C4 and the fifth capacitor C5 are connected in parallel and then have one end connected to the power interface VSS and the other end grounded. The fourth capacitor C4 and the fifth capacitor C5 are filter capacitors.

In some embodiments, the single-path constant current driving circuit 100 further includes a voltage regulator diode D, a first capacitor C1, and a second capacitor C2, wherein an anode of the voltage regulator diode D is connected to the energy storage inductor L, a cathode of the voltage regulator diode D is connected to the first power output terminal 131, a first end of the first capacitor C1 is connected to a second end of the energy storage inductor L, a second end of the first capacitor C1 is connected to a first end of the resistor unit Rx, a first end of the second capacitor C2 is connected to a second end of the energy storage inductor L, and a second end of the second capacitor C2 is grounded. The first and second capacitances C1 and C2 serve to suppress EMC radiation.

In some embodiments, the one-way constant current driving circuit 100 further includes an eleventh resistor R11 and a sixth capacitor C6, one end of the eleventh resistor R11 is connected to the second end of the energy storage inductor L, the other end of the eleventh resistor R11 is connected to one end of the sixth capacitor C6, and the other end of the sixth capacitor C6 is grounded. The eleventh resistor R11 and the sixth capacitor C6 are used to absorb EMC radiation.

In some embodiments, the one-way constant current driving circuit 100 further includes a twelfth resistor R12 and a thirteenth resistor R13, one end of the twelfth resistor R12 is connected to the first power output terminal 131, and the other end of the twelfth resistor R12 is connected to the cathode of the zener diode D. One end of the thirteenth resistor R13 is connected to the second power output end 132, and the other end of the thirteenth resistor R13 is connected to the third end of the constant current driving chip 40.

The embodiment of the application further provides a camera device, which comprises any one of the above single-path constant current driving circuit 100, the single-path constant current driving circuit 100 drives the LEDs with different colors, and the switching of the load current is realized, so that the requirements of the camera device on infrared light supplement and white light supplement are met, the power of the camera device and the power of the infrared light supplement and the white light supplement can be dynamically adjusted, the PWM dynamic dimming of the infrared light and the white light can be realized, and the brightness requirements of different application scenes are met.

The single-channel constant current driving circuit and the image pickup device provided by the embodiment of the present application are described in detail above. The principles and implementations of the present application are described herein using specific examples, which are presented only to aid in understanding the present application. Meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manner and the application scope may be changed, and in summary, the content of the present specification should not be construed as a limitation to the present application.

Claims

1. The utility model provides a single current drive circuit, its characterized in that, single current drive circuit is used for driving the different first way LED lamp of luminescent color and second way LED lamp, single current drive circuit includes:

a drive circuit connected to the switching circuit;

2. The single-circuit constant current driving circuit according to claim 1, wherein the driving circuit comprises a first signal input terminal, a first resistor, a first switch tube and an output terminal, and the first resistor is connected in parallel with the first switch tube;

3. The single-path constant current driving circuit according to claim 2, wherein a control terminal of the first switching tube is connected to the first signal input terminal, a first terminal of the first switching tube is connected to a first terminal of the first resistor, a second terminal of the first switching tube is connected to the output terminal, the first terminal of the first resistor is grounded, and the second terminal of the first resistor is connected to the output terminal.

4. The single-circuit constant current driving circuit according to claim 3, wherein the driving circuit further comprises a resistor unit, a first end of the resistor unit is connected to the second end of the first switching tube, a second end of the resistor unit is connected to the output end, and the resistor unit comprises a plurality of resistors connected in parallel.

5. The single-circuit constant current driving circuit according to claim 2, wherein the single-circuit constant current driving circuit further comprises a power interface;

the first branch comprises a second switching tube, and the control end of the second switching tube is connected with the first signal input end;

when the first signal input end receives the second signal, the second switching tube and the third switching tube are cut off, and the fourth switching tube is conducted to drive the second path of LED lamp.

6. The single-channel constant current driving circuit according to claim 5, wherein the output terminal includes a first power output terminal and a second power output terminal, the first branch further includes a second resistor, a control terminal of the second switch tube is connected to the first signal input terminal, a second terminal of the second switch tube is connected to the first power output terminal, a first terminal of the second switch tube is connected to the second power output terminal, one terminal of the second resistor is connected to the control terminal of the second switch tube, and the other terminal of the second resistor is grounded.

7. The single-channel constant current driving circuit according to claim 6, wherein the second branch further includes a third resistor, a control end of the third switching tube is connected to the first signal input end, a first end of the third switching tube is connected to a control end of the fourth switching tube, a second end of the third switching tube is grounded, a second end of the fourth switching tube is connected to the first power output end, a first end of the fourth switching tube is connected to the second power output end, a first end of the third resistor is connected to the second end of the third switching tube, and a second end of the third resistor is grounded.

8. The single-circuit constant current driving circuit according to claim 7, further comprising a constant current driving chip and an energy storage inductor;

9. The single-circuit constant-current driving circuit according to claim 8, wherein the driving circuit further comprises a second signal input terminal, and the second signal input terminal is connected to the fourth terminal of the constant-current driving chip;

10. An image pickup apparatus comprising the one-way constant current drive circuit according to any one of claims 1 to 9.