Microampere LED drive circuit and cell counter

Abstract

The utility model discloses a microampere-level LED driving circuit and a cell counter, and relates to the technical field of LED driving, the disclosed circuit comprises a switch module and a control module, the switch module is connected with the control module, an LED and a power supply, the control module is used for generating a corresponding PWM driving signal according to a received driving instruction, and the PWM driving signal is connected with the control module. The PWM driving module is used for receiving the PWM driving signal and sending the PWM driving signal to the switch module, and the switch module is used for controlling the driving current input to the LED by the power supply according to the PWM driving signal when receiving the PWM driving signal and carrying out microampere-level current regulation on the LED. Compared with the prior art that the constant current adjustment range of the LED drive circuit is higher than the milliampere level, the control module adjusts the brightness of the LED through the PWM drive signal, so that microampere-level current adjustment is achieved, and the current required by special occasions is met.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of LED driving, in particular to a microampere-level LED driving circuit and a cell counter. BACKGROUND

[0002] LED driving technology refers to technology for providing stable current or voltage for an LED (light-emitting diode) to ensure normal light emission and achieve predetermined performance. In LED driving technology, there are various driving schemes according to the characteristics and application requirements of the LED, including but not limited to linear driving, switching power supply driving, constant current driving, etc.

[0003] The constant current adjustment range of a conventional LED driving circuit is above mA, but smaller current is required in special occasions, for example, micro-light display, light sensors, and low-power electronic devices. CONTENT OF THE INVENTION

[0004] The main purpose of the application is to provide a microampere-level LED driving circuit and a cell counter, aiming to solve the technical problem of the constant current adjustment range of the LED driving circuit being above mA in the prior art.

[0005] To achieve the above-mentioned purpose, the application provides a microampere-level LED driving circuit, which comprises a switching module and a control module.

[0006] The switching module is connected with the control module, the LED and the power supply respectively.

[0007] The control module is used for generating a corresponding PWM driving signal according to the received driving instruction and sending the PWM driving signal to the switching module.

[0008] The switching module is used for controlling the driving current input to the LED by the power supply according to the PWM driving signal when the PWM driving signal is received, and performing microampere-level current adjustment on the LED.

[0009] Optionally, the switching module comprises a first switching unit, a second switching unit, a third switching unit and a fourth switching unit.

[0010] The first switching unit is connected with the control module and the third switching unit respectively, the second switching unit is connected with the control module and the LED respectively, the third switching unit is connected with the LED, and the fourth switching unit is connected with the control unit.

[0011] The first switching unit is used for sending a switching signal to the third switching unit when the control module receives a driving instruction.

[0012] The third switch unit is configured to turn on a circuit between the power supply and the LED when a switch signal is received.

[0013] The second switch unit is configured to control on-off of a circuit between the LED and the fourth switch unit when a first PWM driving signal of the control module is received.

[0014] The fourth switch unit is configured to control on-off of a circuit between the power supply and the second switch unit when a second PWM driving signal of the control module is received.

[0015] Optionally, the control module comprises a first control unit and a second control unit.

[0016] The first control unit is connected with the second control unit, the first switch unit and the fourth switch unit respectively, and the second control unit is connected with the second switch unit respectively.

[0017] The first control unit is configured to send a driving signal to the first switch unit and a control signal to the second control unit when a driving instruction is received.

[0018] The second control unit is configured to send a first PWM driving signal to the second switch unit when a control signal is received.

[0019] The first control unit is further configured to send a second PWM driving signal to the fourth switch unit when a driving instruction is received.

[0020] Optionally, the first switch unit comprises a first triode.

[0021] The base of the first triode is connected with an output pin of the first control unit, the collector of the first triode is connected with the third switch unit, and the emitter of the first triode is grounded.

[0022] Optionally, the second switch unit comprises a second triode.

[0023] The base of the second triode is connected with an output pin of the second control unit, the collector of the second triode is connected with a cathode of the LED, and the emitter of the second triode is connected with a voltage detection pin of the second control unit.

[0024] Optionally, the third switch unit comprises a first MOS tube.

[0025] The gate of the first MOS tube is connected with the first switch unit, the source of the first MOS tube is connected with an anode of the LED, and the drain of the first MOS tube is connected with the power supply.

[0026] Optionally, the fourth switch unit comprises a second MOS tube.

[0027] The gate of the second MOS tube is connected with the second PWM drive pin of the first control unit, the source of the second MOS tube is connected with the second switch unit, and the drain of the second MOS tube is connected with the power supply.

[0028] Optionally, the microampere-level LED driving circuit further comprises a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor.

[0029] The first end of the first resistor is connected with the output pin of the first control unit, the second end of the first resistor is connected with the first switch unit and the first end of the second resistor respectively, the second end of the second resistor is grounded, the first end of the third resistor is connected with the power supply and the third switch unit respectively, the second end of the third resistor is connected with the first switch unit and the third switch unit respectively, the first end of the fourth resistor is connected with the voltage detection pin of the second control unit and the second switch unit respectively, the second end of the fourth resistor is connected with the first end of the fifth resistor, and the second end of the fifth resistor is grounded.

[0030] Optionally, the microampere-level LED driving circuit further comprises a capacitor, an inductor and a diode.

[0031] The first end of the capacitor is connected with the second end of the inductor, the second end of the fourth resistor and the first end of the fifth resistor, the second end of the capacitor is grounded, the first end of the inductor is connected with the fourth switch unit and the negative electrode of the diode, and the positive electrode of the diode is grounded.

[0032] In addition, in order to achieve the above object, the utility model further provides a cell counter, the cell counter comprises the microampere-level LED driving circuit as described above.

[0033] The one or more technical solutions provided in the application have at least the following effects:

[0034] The application provides a micro-ampere LED driving circuit and a cell counter, the micro-ampere LED driving circuit comprising: a switching module and a control module, the switching module being connected with the control module, an LED and a power supply respectively, the control module being used for generating a corresponding PWM driving signal according to a received driving instruction and sending the PWM driving signal to the switching module, and the switching module being used for controlling driving current input to the LED by the power supply according to the PWM driving signal when the PWM signal is received, so as to perform micro-ampere current adjustment on the LED. Compared with the prior art, the control module adjusts the brightness of the LED by the PWM driving signal in the application, so that the micro-ampere current adjustment is realized, so as to meet the required current in special occasions. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, those drawings can also provide other drawings for those skilled in the art without creative labor.

[0036] Figure 1 The structural schematic diagram of the first embodiment of the micro-ampere LED driving circuit provided by the present application is shown in the figure.

[0037] Figure 2 The structural schematic diagram of the second embodiment of the micro-ampere LED driving circuit provided by the present application is shown in the figure.

[0038] Figure 3 The circuit principle diagram of the second embodiment of the micro-ampere LED driving circuit provided by the present application is shown in the figure.

[0039] Figure 4 The circuit principle diagram of the first control unit in the second embodiment of the micro-ampere LED driving circuit provided by the present application is shown in the figure.

[0040] Explanation of reference numerals:

[0041] Reference Name Reference Name 1 Control module 2 Switch module 11 / U1 First control unit 12 / U2 Second control unit 21 First switch unit 22 Second switch unit 23 Third switch unit 24 Fourth switch unit Q1 First transistor Q2 Second transistor Q3 First MOS transistor Q4 Second MOS transistor R1 First resistor R2 Second resistor R3 Third resistor R4 Fourth resistor R5 Fifth resistor C Capacitor L Inductor D1 LED D2 Diode

[0042] The purpose of the present application, the functional characteristics and the advantages will be further described with reference to the embodiments and the drawings. DETAILED DESCRIPTION

[0043] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application, and are not used to limit the present application.

[0044] With reference to the drawings and embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0045] It should be noted that all directional indications, such as upper, lower, left, right, front, back, and the like, used in the embodiments of the present application are only used to explain the relative position relationship, movement condition and the like between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly.

[0046] In addition, the description of "first", "second" and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of various embodiments can be combined with each other, but it must be based on the fact that a person of ordinary skill in the art can realize it, and when the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the scope of protection claimed by the present application.

[0047] The main solution of the embodiments of the present application is that the control module 1 generates a corresponding PWM driving signal according to the received driving instruction, and sends the PWM driving signal to the switching module 2. When the switching module 2 receives the PWM signal, it controls the driving current of the power input to the LED according to the PWM driving signal, and adjusts the current of the LED to the microampere level.

[0048] The constant current adjustment range of the traditional LED driving circuit is above mA, but smaller current is needed in special occasions.

[0049] The present application provides a solution. The control module 1 generates a corresponding PWM driving signal according to the received driving instruction, and sends the PWM driving signal to the switching module 2. When the switching module 2 receives the PWM signal, it controls the driving current of the power input to the LED according to the PWM driving signal, and adjusts the current of the LED to the microampere level. Compared with the constant current adjustment range of the LED driving circuit in the prior art, which is above mA, the control module 1 in the present application adjusts the brightness of the LED through the PWM driving signal, thereby realizing the current adjustment to the microampere level to meet the required current in special occasions.

[0050] Based on this, the embodiments of the present application provide a microampere level LED driving circuit.

[0051] Reference Figure 1 , Figure 1 The structural schematic diagram of a first embodiment of a microampere-level LED driving circuit proposed by the embodiment of the present application is shown in the figure.

[0052] In order to meet the current required by special occasions and further to adjust the current of the LED to the microampere level, based on the first embodiment, as shown in the figure, the microampere-level LED driving circuit of the embodiment comprises a switching module 2 and a control module 1. Figure 1

[0053] The switching module 2 is connected with the control module 1, the LED and the power supply respectively.

[0054] The control module 1 is configured to generate a corresponding PWM driving signal according to the received driving instruction and send the PWM driving signal to the switching module 2.

[0055] The switching module 2 is configured to control the driving current input to the LED by the power supply according to the PWM driving signal when the PWM driving signal is received, so as to adjust the current of the LED to the microampere level.

[0056] It should be noted that the PWM (Pulse Width Modulation) driving signal can realize approximate or accurate control of the analog signal by adjusting the duty cycle (i.e. the ratio of the high level duration to the total cycle time), and when the duty cycle of the PWM driving signal changes, the average current will also change accordingly, so as to realize the control of the current in the circuit.

[0057] It can be understood that the driving instruction can be issued by the upper computer system to control the brightness of the LED.

[0058] In the embodiment, the control module 1 generates a corresponding PWM driving signal according to the received driving instruction and sends the PWM driving signal to the switching module 2, and the switching module 2 controls the driving current input to the LED by the power supply according to the PWM driving signal when the PWM signal is received, so as to adjust the current of the LED to the microampere level to meet the current required by special occasions.

[0059] Reference Figure 2 , Figure 2 The structural schematic diagram of a second embodiment of a microampere-level LED driving circuit proposed by the embodiment of the present application is shown in the figure.

[0060] In order to control the LED, based on the second embodiment, as shown in the figure, the microampere-level LED driving circuit of the embodiment comprises a switching module 2 and a control module 1. Figure 2 ​As shown, the switch module 2 described in the embodiment includes: a first switch unit 21, a second switch unit 22, a third switch unit 23 and a fourth switch unit 24.

[0061] The first switch unit 21 is connected with the control module 1 and the third switch unit 23 respectively, the second switch unit 22 is connected with the control module 1 and the LED respectively, the third switch unit 23 is connected with the LED, and the fourth switch unit 24 is connected with the control unit respectively.

[0062] The first switch unit 21 is configured to send a switch signal to the third switch unit 23 when the control module 1 receives a driving instruction.

[0063] The third switch unit 23 is configured to turn on the circuit between the power supply and the LED when receiving the switch signal.

[0064] The second switch unit 22 is configured to control the on-off of the circuit between the LED and the fourth switch unit 24 when receiving the first PWM driving signal of the control module 1.

[0065] The fourth switch unit 24 is configured to control the on-off of the circuit between the power supply and the second switch unit 22 when receiving the second PWM driving signal of the control module 1.

[0066] It should be noted that the switch signal can be a current signal or a voltage signal, which can be set according to actual conditions, and the embodiment is not limited thereto. The first PWM driving signal and the second PWM driving signal can achieve approximate or accurate control of the analog signal by adjusting the duty cycle (i.e. the ratio of high level duration to total cycle time). When the duty cycle of the first PWM driving signal and the second PWM driving signal changes, the average current also changes accordingly, thereby achieving control of the current in the circuit.

[0067] In a specific implementation, the first switch unit 21 sends a switch signal to the third switch unit 23 when the control module 1 receives a driving instruction, the third switch unit 23 turns on the circuit between the power supply and the LED when receiving the switch signal, the second switch unit 22 controls the on-off of the circuit between the LED and the fourth switch unit 24 when receiving the first PWM driving signal of the control module 1, and the fourth switch unit 24 controls the on-off of the circuit between the power supply and the second switch unit 22 when receiving the second PWM driving signal of the control module 1, thereby achieving control of the brightness of the LED.

[0068] Further, the control module 1 includes: a first control unit 11 and a second control unit 12.

[0069] The first control unit 11 is connected with the second control unit 12, the first switch unit 21 and the fourth switch unit 24 respectively, and the second control unit 12 is connected with the second switch unit 22 respectively.

[0070] The first control unit 11 is configured to send a driving signal to the first switch unit 21 and send a control signal to the second control unit 12 when receiving a driving instruction.

[0071] The second control unit 12 is configured to send a first PWM driving signal to the second switch unit 22 when receiving the control signal.

[0072] The first control unit 11 is further configured to send a second PWM driving signal to the fourth switch unit 24 when receiving the driving instruction.

[0073] It should be noted that the control signal can be a current signal or a voltage signal, which can be set according to actual conditions, and the embodiment is not limited.

[0074] In specific implementation, the first control unit 11 sends a driving signal to the first switch unit 21 and sends a control signal to the second control unit 12 when receiving a driving instruction, the second control unit 12 sends a first PWM driving signal to the second switch unit 22 when receiving the control signal, and the first control unit 11 sends a second PWM driving signal to the fourth switch unit 24 when receiving the driving instruction, so as to realize the control of the LED brightness.

[0075] Reference Figure 3 , Figure 3 The circuit principle diagram of the third embodiment of the microampere-level LED driving circuit proposed in the embodiment is shown.

[0076] Based on the third embodiment, as shown in Figure 3 and Figure 4 The first switch unit 21 includes a first triode Q1.

[0077] The base of the first triode Q1 is connected with the output pin of the first control unit 11, the collector of the first triode is connected with the third switch unit 23, and the emitter of the first triode Q1 is grounded.

[0078] In specific implementation, the first triode Q1 sends a switch signal to the third switch unit 23 when receiving the driving signal of the first control unit 11.

[0079] Further, the second switch unit 22 includes a second triode Q2.

[0080] The base of the second triode Q2 is connected with the output pin of the second control unit 12, the collector of the second triode is connected with the cathode of the LED, and the emitter of the second triode Q2 is connected with the voltage detection pin of the second control unit 12.

[0081] In a specific implementation, the second triode Q2 controls the on-off of the circuit between the LED and the fourth switch unit 24 when receiving the first PWM driving signal of the second control unit 12.

[0082] Further, the third switch unit 23 comprises a first MOS tube Q3.

[0083] The gate of the first MOS tube Q3 is connected with the first switch unit 21, the source of the first MOS tube Q3 is connected with the anode of the LED, and the drain of the first MOS tube Q3 is connected with the power supply.

[0084] In a specific implementation, the first MOS tube Q3 turns on the circuit between the power supply and the LED when receiving the switch signal of the first triode Q1.

[0085] Further, the fourth switch unit 24 comprises a second MOS tube Q4.

[0086] The gate of the second MOS tube Q4 is connected with the second PWM driving pin of the first control unit 11, the source of the second MOS tube Q4 is connected with the second switch unit 22, and the drain of the second MOS tube Q4 is connected with the power supply.

[0087] In a specific implementation, the second MOS tube Q4 controls the on-off of the circuit between the power supply and the inductor when receiving the second PWM driving signal of the second control unit 12.

[0088] Further, the microampere-level LED driving circuit further comprises a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4 and a fifth resistor R5.

[0089] The first end of the first resistor R1 is connected with the output pin of the first control unit 11, the second end of the first resistor R1 is connected with the first switch unit 21 and the first end of the second resistor R2 respectively, the second end of the second resistor R2 is grounded, the first end of the third resistor R3 is connected with the power supply and the third switch unit 23 respectively, the second end of the third resistor R3 is connected with the first switch unit 21 and the third switch unit 23 respectively, the first end of the fourth resistor R4 is connected with the voltage detection pin of the second control unit 12 and the second switch unit 22 respectively, the second end of the fourth resistor R4 is connected with the first end of the fifth resistor R5, and the second end of the fifth resistor R5 is grounded.

[0090] It should be noted that the fourth resistor R4 is used for voltage sampling, and the collected voltage is fed back to the second control unit 12.

[0091] Further, the micro-ampere level LED driving circuit further comprises a capacitor C, an inductor L and a diode D2.

[0092] The first end of the capacitor C is connected with the second end of the inductor L, the second end of the fourth resistor R4 and the first end of the fifth resistor R5, the second end of the capacitor C is grounded, the first end of the inductor L is connected with the fourth switch unit 24 and the negative electrode of the diode D2, and the positive electrode of the diode D2 is grounded.

[0093] It should be noted that the capacitor C, the inductor L, the diode D2 and the second MOS tube Q4 constitute a voltage reduction circuit, and the voltage of the negative electrode of the LED can be adjusted by sending a second PWM driving signal by the second control unit 12, so as to meet the working voltage requirements of different LEDs.

[0094] In a specific implementation, when the second switch unit 22 controls the second MOS tube Q4 to be turned on, the power supply charges the inductor L, and when the second switch unit 22 controls the second MOS tube Q4 to be turned off, the inductor L discharges the negative electrode of the LED, so as to realize the control of the voltage of the negative electrode of the LED.

[0095] To achieve the above object, the application further provides a cell counter comprising the micro-ampere level LED driving circuit.

[0096] The above is only the preferred embodiment of the application, and does not limit the patent scope of the application, and any equivalent structure or equivalent flow transformation by using the content of the specification and the drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the application.

Claims

1. A microampere-level LED driving circuit, characterized in that, The microampere LED is applied to a cell counter, and a microampere LED driving circuit comprises a switching module and a control module. The switching module is connected with the control module, the LED and the power supply respectively. The control module is configured to generate a corresponding PWM driving signal according to a received driving instruction and send the PWM driving signal to the switching module. The switching module is configured to control driving current input to the LED by the power supply according to the PWM driving signal when the PWM driving signal is received, so as to adjust the current of the LED at a microampere level. The switching module comprises a first switching unit, a second switching unit, a third switching unit and a fourth switching unit. The first switching unit is connected with the control module and the third switching unit respectively, the second switching unit is connected with the control module and the LED respectively, the third switching unit is connected with the LED, and the fourth switching unit is connected with the control module. The first switching unit is configured to send a switching signal to the third switching unit when the control module receives the driving instruction. The third switching unit is configured to turn on a circuit between the power supply and the LED when the switching signal is received. The second switching unit is configured to control the on-off of a circuit between the LED and the fourth switching unit when a first PWM driving signal of the control module is received. The fourth switching unit is configured to control the on-off of a circuit between the power supply and the second switching unit when a second PWM driving signal of the control module is received. The control module comprises a first control unit and a second control unit. The first control unit is connected with the second control unit, the first switching unit and the fourth switching unit respectively, and the second control unit is connected with the second switching unit respectively. The first control unit is configured to send a driving signal to the first switching unit and send a control signal to the second control unit when the driving instruction is received. The second control unit is configured to send a first PWM driving signal to the second switching unit when the control signal is received. The first control unit is further configured to send a second PWM driving signal to the fourth switching unit when the driving instruction is received.

2. The microamp LED driving circuit according to claim 1, wherein, The first switching unit comprises a first triode. The base of the first triode is connected with an output pin of the first control unit, the collector of the first triode is connected with the third switching unit, and the emitter of the first triode is grounded.

3. The microamp LED driving circuit according to claim 1, wherein, The second switching unit comprises a second triode. The base of the second triode is connected with an output pin of the second control unit, the collector of the second triode is connected with the cathode of the LED, and the emitter of the second triode is connected with a voltage detection pin of the second control unit.

4. The microamp LED driving circuit according to claim 1, wherein, The third switching unit comprises a first MOS tube. The gate of the first MOS tube is connected with the first switching unit, the source of the first MOS tube is connected with the anode of the LED, and the drain of the first MOS tube is connected with the power supply.

5. The microamp LED driving circuit according to claim 1, wherein, The fourth switch unit comprises a second MOS tube; The gate of the second MOS tube is connected with the second PWM drive pin of the first control unit, the source of the second MOS tube is connected with the second switch unit, and the drain of the second MOS tube is connected with the power supply.

6. The microamp LED driver circuit of claim 1, wherein, The microampere-level LED drive circuit further comprises a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor; The first end of the first resistor is connected with the output pin of the first control unit, the second end of the first resistor is connected with the first switch unit and the first end of the second resistor respectively, the second end of the second resistor is grounded, the first end of the third resistor is connected with the power supply and the third switch unit respectively, the second end of the third resistor is connected with the first switch unit and the third switch unit respectively, the first end of the fourth resistor is connected with the voltage detection pin of the second control unit and the second switch unit respectively, the second end of the fourth resistor is connected with the first end of the fifth resistor, and the second end of the fifth resistor is grounded.

7. The microampere-level LED driving circuit as described in claim 6, characterized in that, The microampere-level LED drive circuit further comprises a capacitor, an inductor and a diode; The first end of the capacitor is connected with the second end of the inductor, the second end of the fourth resistor and the first end of the fifth resistor, the second end of the capacitor is grounded, the first end of the inductor is connected with the fourth switch unit and the negative electrode of the diode, and the positive electrode of the diode is grounded.

8. A cytometer characterized by, The cell counter comprises the microampere-level LED drive circuit according to any one of claims 1 to 7.

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