LED time-sharing circuit based on single control signal port
By designing an LED time-sharing circuit based on a single control signal port, and using components such as switches and diodes to realize the power time-sharing output, the problems of large number of constant current sources and high cost in the prior art are solved, and the effect of double the number of driving RGBs is achieved.
Patent Information
- Application Number
- CN202420603223.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-26
- Publication Date
- 2025-03-14
- Estimated Expiration
- 2034-03-26
AI Technical Summary
When driving multi-color LEDs, existing LED time-sharing circuits require multiple constant current sources, resulting in increased costs and low cost performance.
A LED time-sharing circuit based on a single control signal port is designed. Through switches Q1, Q2, Q3, diodes D1, D2, D3 and other components, the power supply time-sharing output is realized, and only a single control signal port is required.
The effect of double the number of driver RGBs is achieved, while reducing costs, and solving the problems of large number and high cost in the prior art.
Smart Images
Figure CN222621236U_ABST
Abstract
Description
[Technical field]
[0001] The utility model relates to the technical field of LED dimming, in particular to an LED time-sharing circuit based on a single control signal port. [Background technology]
[0002] With the continuous development of vehicle interior lighting, the number of RGB (Red Green Blue, i.e. multi-color LED) is also gradually increasing, which means that more constant current sources are needed, which increases the cost of the solution.
[0003] To solve this problem, a time-sharing circuit is added to double the number of RGBs driven by the LED Driver.
[0004] 1) Most of the existing technical solutions for time-sharing applications are integrated inside the LED Driver. Such LED Drivers have a large number of internal constant current sources and are costly. If the number of RGB is small, the price of such drivers is not cost-effective.
[0005] 2) Please refer to Figure 1 As shown in the figure, it is a circuit diagram of an LED time-sharing circuit in the prior art, which adopts an external time-sharing scheme and has requirements for the GPIO and VIN input voltages. The difference between the two needs to be less than the conduction voltage drop of the transistor Vbe. Among them, when GPIO is high, the transistor Q1 is turned on. To satisfy the closure of the transistor Q3, the difference between the VIN and GPIO voltages must be less than the Vbe conduction voltage of the transistor Q3.
[0006] Therefore, it is necessary to propose a new technical solution to solve the above problems. [Utility Model Content]
[0007] One of the purposes of the utility model is to provide an LED time-sharing circuit based on a single control signal port, which only needs a single control signal port to control the power supply time-sharing output, so that the number of driven RGB is doubled.
[0008] According to one aspect of the utility model, the utility model provides an LED time-sharing circuit based on a single control signal port, which includes a switch Q1, a switch Q2, a switch Q3, a diode D1, a diode D2, a diode D3, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a power input terminal VIN, a control signal terminal GPIO, a first voltage output terminal HVIO1 and a second voltage output terminal HVIO2, wherein the power input terminal VIN is connected to a power supply; the positive electrode of the diode D1 is connected to the power input terminal VIN, and the negative electrode thereof is connected to the first connection terminal of the switch Q1; the second connection terminal of the switch Q1 is connected to the first voltage output terminal HVIO1, and the control signal terminal GPIO ... The first connecting end of the switch Q2 is connected to the first connecting end of the switch Q1, the second connecting end thereof is connected to the second voltage output end HVIO2, and the control end thereof is connected to the first connecting end thereof through the resistor R6; the anode of the diode D3 is connected to the second voltage output end HVIO2, and the cathode thereof is connected to the cathode of the diode D2; the first connecting end of the switch Q3 is connected to the control end of the switch Q2 through the resistor R2, and the control end thereof is connected to the control signal end GPIO through the resistor R4; one end of the resistor R3 is connected to the control end of the switch Q3, and the other end thereof is grounded.
[0009] Further, when the control signal received by the control signal terminal GPIO is a first logic level, the switch Q2 and the switch Q3 are turned on, and the switch Q1 is turned off. At this time, the voltage of the power input terminal VIN is provided to the second voltage output terminal HVIO2 via the switch Q2; when the control signal received by the control signal terminal GPIO is a second logic level, the switch Q2 and the switch Q3 are turned off, and the switch Q1 is turned on. At this time, the voltage of the power input terminal VIN is provided to the first voltage output terminal HVIO1 via the switch Q1.
[0010] Further, the switch Q1 is a PNP type transistor, and the first connection end, the second connection end and the control end of the switch Q1 are respectively the emitter, the collector and the base of the PNP type transistor; the switch Q2 is a PNP type transistor, and the first connection end, the second connection end and the control end of the switch Q2 are respectively the emitter, the collector and the base of the PNP type transistor; the switch Q3 is an NPN type transistor, and the first connection end, the second connection end and the control end of the switch Q3 are respectively the collector, the emitter and the base of the NPN type transistor.
[0011] Furthermore, the LED is two multi-color LEDs, namely a first multi-color LED and a second multi-color LED, the anode of the first multi-color LED is connected to the first voltage output terminal HVIO1, and the cathode thereof is connected to the constant current source module; the anode of the second multi-color LED is connected to the second voltage output terminal HVIO2, and the cathode thereof is connected to the constant current source module.
[0012] Compared with the prior art, the utility model only needs a single control signal port to control the time-sharing output of the power supply, so that the number of driven RGB is doubled.
Brief Description of the Drawings
[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following briefly introduces the drawings required for the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:
[0014] Figure 1 It is a circuit diagram of an LED time-sharing circuit in the prior art;
[0015] Figure 2 This is a circuit diagram of an LED time-sharing circuit based on a single control signal port in one embodiment of the utility model;
[0016] Figure 3 FIG. 4 is a circuit diagram of an LED driving system in one embodiment of the present invention. [Specific implementation method]
[0017] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.
[0018] The "one embodiment" or "embodiment" referred to herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the utility model. The "in one embodiment" that appears in different places in this specification does not all refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments. Unless otherwise specified, the words "coupled", "connected", "connected" and "connected" in this document that indicate electrical connection all mean direct or indirect connection. For example, A is connected to B, which includes both direct electrical connection between A and B and connection between A and B through electrical components or circuits.
[0019] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "front", "back", "left", "right", "vertical", "perpendicular", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.
[0020] Please refer to Figure 2 As shown, it is a circuit diagram of an LED time-sharing circuit based on a single control signal port in one embodiment of the utility model. Figure 2 The LED time-sharing circuit based on a single control signal port shown includes a switch Q1, a switch Q2, a switch Q3, a diode D1, a diode D2, a diode D3, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a power input terminal VIN, a control signal terminal GPIO, a first voltage output terminal HVIO1 and a second voltage output terminal HVIO2.
[0021] Among them, the power input terminal VIN is connected to the power supply; the anode of the diode D1 is connected to the power input terminal VIN, and the cathode of the diode D1 is connected to the first connection terminal of the switch Q1; the second connection terminal of the switch Q1 is connected to the first voltage output terminal HVIO1, and the control terminal thereof is connected to the anode of the diode D2 via the resistor R5, and the cathode of the diode D2 is grounded via the resistor R1; the first connection terminal of the switch Q2 is connected to the first connection terminal of the switch Q1, and the second connection terminal thereof is connected to the second voltage output terminal HVIO2, and the control terminal thereof is connected to the first connection terminal thereof via the resistor R6; the anode of the diode D3 is connected to the second voltage output terminal HVIO2, and the cathode of the diode D2 is connected; the first connection terminal of the switch Q3 is connected to the control terminal of the switch Q2 via the resistor R2, and the control terminal thereof is connected to the control signal terminal GPIO via the resistor R4; one end of the resistor R3 is connected to the control terminal of the switch Q3, and the other end thereof is grounded.
[0022] exist Figure 2 In the embodiment shown, the switch Q1, the switch Q2 and the switch Q3 are all triodes; the control signal terminal GPIO is an I / O port. The switch Q1 is a PNP triode, and the first connection terminal, the second connection terminal and the control terminal of the switch Q1 are respectively the emitter, the collector and the base of the PNP triode; the switch Q2 is a PNP triode, and the first connection terminal, the second connection terminal and the control terminal of the switch Q2 are respectively the emitter, the collector and the base of the PNP triode; the switch Q3 is an NPN triode, and the first connection terminal, the second connection terminal and the control terminal of the switch Q3 are respectively the collector, the emitter and the base of the NPN triode.
[0023] The following is a detailed introduction Figure 2 The working principle of the LED time-sharing circuit based on a single control signal port is shown.
[0024] When the control signal received by the control signal terminal GPIO is at a high level, GPIO is connected to the ground through resistors R3 and R4, and the voltage division on resistor R3 (i.e., the voltage connected to node B) is greater than the conduction voltage of Vbe (i.e., the voltage difference between the base and the emitter) of the NPN transistor Q3. At this time, the NPN transistor Q3 is turned on, and its base potential is limited to about 0.7V. After the NPN transistor Q3 is turned on, the collector voltage of the NPN transistor Q3 is pulled down, thereby causing the base voltage of the PNP transistor Q2 to also become lower. The Vbe voltage applied to the PNP transistor Q2 is greater than the conduction voltage of Vbe, and the PNP transistor Q2 is turned on. The power input terminal VIN reaches the second voltage output terminal HVIO2 through the PNP transistor Q2 to supply power to the next stage. After the PNP transistor Q2 is turned on, the second voltage output terminal HVIO2 and the base of the PNP transistor Q1 are basically equal, which is less than the Vbe turn-on voltage of the PNP transistor Q1. At this time, the PNP transistor Q1 is disconnected, and the first voltage output terminal HVIO1 is blocked. D2 raises the base voltage of the transistor Q1 to prevent Q1 from being turned on by mistake when the GPIO outputs a high level.
[0025] Similarly, when the control signal received by the control signal terminal GPIO is at a low level, the Vbe (i.e., the voltage difference between the base and the emitter) of the NPN transistor Q3 does not reach the turn-on voltage, and the NPN transistor Q3 is turned off, thereby causing the PNP transistor Q2 to also be turned off. At this time, the base of the PNP transistor Q1 is pulled down to the ground through the resistor R5, the diode D2 and the resistor R1, and the Vbe of the PNP transistor Q1 is greater than its conduction voltage drop. The power input terminal VIN supplies power to the subsequent stage through the PNP transistor Q1; due to the action of the diode D3, the voltage of the power input terminal VIN will not be fed back to the second voltage output terminal HVIO2 through the BE path of the PNP transistor Q1.
[0026] It can also be said that when the control signal received by the control signal terminal GPIO is at a high level (which can be called the first logic level of the control signal), the switches Q2 and Q3 are turned on, and the switch Q1 is turned off. At this time, the voltage of the power input terminal VIN is provided to the second voltage output terminal HVIO2 via the switch Q2; when the control signal received by the control signal terminal GPIO is at a low level (which can be called the second logic level of the control signal), the switches Q2 and Q3 are turned off, and the switch Q1 is turned on. At this time, the voltage of the power input terminal VIN is provided to the first voltage output terminal HVIO1 via the switch Q1.
[0027] Please refer to Figure 3As shown, it is a circuit diagram of an LED driving system in one embodiment of the utility model. Figure 3 The LED driving system shown includes the following Figure 2 The LED time-sharing circuit 310 based on a single control signal port, two multi-color LEDs and a constant current source module 320 are shown. The two multi-color LEDs (i.e., two RGB) are respectively a first multi-color LED1 and a second multi-color LED2, wherein the anode of the first multi-color LED1 is connected to the first voltage output terminal HVIO1, and the cathode thereof is connected to the constant current source module 320; the anode of the second multi-color LED2 is connected to the second voltage output terminal HVIO2, and the cathode thereof is connected to the same constant current source module 320.
[0028] In summary, the LED time-sharing circuit based on a single control signal port provided by the utility model is an RGB external time-sharing driving circuit, which can double the number of driven RGB; the MCU (Microcontroller Unit) provides a GPIO as a control signal, and the voltage of the power input terminal VIN is divided into two paths for use. When the GPIO state is continuously switched between high and low, the first voltage output terminal HVIO1 and the second voltage output terminal HVIO2 are alternately turned on, which plays a time-sharing role.
[0029] Based on the above analysis, the beneficial effects of the LED time-sharing circuit based on a single control signal port provided by the utility model are:
[0030] 1) Q1 and Q2 use PNP transistors, which are operated in saturation when turned on to reduce the loss between Vce (i.e. the voltage difference between the collector and the emitter); NPN transistors cannot do this;
[0031] 2) Only three transistors are used to achieve a two-time-sharing circuit, which saves more costs;
[0032] 3) It solves the problem that the existing time-sharing circuit needs to meet the requirement that the difference between the GPIO output high voltage and the input voltage needs to be less than the transistor Vbe conduction voltage;
[0033] 4) Select appropriate resistance to make PNP transistor Q2 saturated and turned on, and Vbe of Q1 is less than the turn-on voltage, thus turning off Q1;
[0034] 5) Diodes D2 and D3 solve the problem of voltage backflow.
[0035] It should be noted that any changes made by those skilled in the art to the specific implementation of the present invention do not deviate from the scope of the claims of the present invention. Accordingly, the scope of the claims of the present invention is not limited to the aforementioned specific implementation.
Claims
1. An LED time-sharing circuit based on a single control signal port, characterized in that: It includes a switch Q1, a switch Q2, a switch Q3, a diode D1, a diode D2, a diode D3, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a power input terminal VIN, a control signal terminal GPIO, a first voltage output terminal HVIO1 and a second voltage output terminal HVIO2, The power input terminal VIN is connected to the power supply; the anode of the diode D1 is connected to the power input terminal VIN, and the cathode of the diode D1 is connected to the first connection terminal of the switch Q1; the second connection terminal of the switch Q1 is connected to the first voltage output terminal HVIO1, the control terminal of the diode D1 is connected to the control terminal of the switch Q1 via the resistor R5, and the cathode of the diode D2 is grounded via the resistor R1; the first connection terminal of the switch Q2 is connected to the first connection terminal of the switch Q1, the second connection terminal of the diode D3 is connected to the second voltage output terminal HVIO2, and the control terminal of the diode D3 is connected to the first connection terminal of the switch Q1 via the resistor R6; the anode of the diode D3 is connected to the second voltage output terminal HVIO2, and the cathode of the diode D3 is connected to the cathode of the diode D2; the first connection terminal of the switch Q3 is connected to the control terminal of the switch Q2 via the resistor R2, and the control terminal of the diode D3 is connected to the control signal terminal GPIO via the resistor R4; one end of the resistor R3 is connected to the control terminal of the switch Q3, and the other end of the resistor R3 is grounded.
2. The LED time-sharing circuit based on a single control signal port according to claim 1, characterized in that: When the control signal received by the control signal terminal GPIO is at a first logic level, the switch Q2 and the switch Q3 are turned on, and the switch Q1 is turned off. At this time, the voltage of the power input terminal VIN is provided to the second voltage output terminal HVIO2 via the switch Q2; When the control signal received by the control signal terminal GPIO is at the second logic level, the switch Q2 and the switch Q3 are turned off, and the switch Q1 is turned on. At this time, the voltage of the power input terminal VIN is provided to the first voltage output terminal HVIO1 through the switch Q1.
3. The LED time-sharing circuit based on a single control signal port according to claim 2, characterized in that: The switch Q1 is a PNP transistor, and the first connection end, the second connection end and the control end of the switch Q1 are respectively the emitter, the collector and the base of the PNP transistor; The switch Q2 is a PNP transistor, and the first connection end, the second connection end and the control end of the switch Q2 are respectively the emitter, the collector and the base of the PNP transistor; The switch Q3 is an NPN transistor, and the first connection end, the second connection end and the control end of the switch Q3 are respectively the collector, the emitter and the base of the NPN transistor.
4. The LED time-sharing circuit based on a single control signal port according to any one of claims 1 to 3, characterized in that: The LEDs are two multi-color LEDs, namely a first multi-color LED and a second multi-color LED. The anode of the first multi-color LED is connected to the first voltage output terminal HVIO1, and the cathode thereof is connected to the constant current source module; The anode of the second multi-color LED is connected to the second voltage output terminal HVIO2, and the cathode of the second multi-color LED is connected to the constant current source module.