Multi-switch detection and LED drive multiplexing system

Abstract

The invention discloses a multi-switch detection and LED drive multiplexing system, which comprises an integrated circuit module, a switch module and an LED lamp, and is characterized in that the integrated circuit module comprises a logic circuit, an LED drive circuit, a level identification circuit and a PIN pin; the PIN pin is electrically connected with the output end of the LED driving circuit, the input end of the level identification circuit, the output end of the switch module and the LED lamp, the input end of the switch module inputs voltage VCC, and the logic circuit controls and enables the LED driving circuit and the level identification circuit; the switch module inputs a voltage V0 to the PIN pin, the level identification circuit detects the state change of the switch module according to the change of the voltage V0 and feeds back a detection signal to the logic circuit, and the voltage V0 is smaller than the forward voltage VF of the LED lamp, so that the LED lamp is prevented from being driven by the switch module.

Description

Technical Field

[0001] The invention relates to the technical field of integrated circuits, and in particular to a multiplex system for multi-switch detection and LED driving. Background Art

[0002] With the continuous advancement of science and technology, consumer electronic products have become popular, and electronic products are generally equipped with integrated circuits to achieve intelligent interaction with users. At the same time, the size requirements of consumer electronic products are becoming more and more stringent. In order to meet the needs of lightness, thinness and miniaturization, many modern integrated circuit designs use smaller packages, which leads to fewer pins. The reduction in the number of pins can not only reduce the cost of packaging materials, but also simplify the production process and improve the yield. Although this trend helps to reduce costs and save space, it also poses some new challenges, especially in signal detection and control. Electronic devices generally have the function of interacting with users in multiple actions. For example, traditional integrated circuits detect switch actions through multiple pins to identify multiple user actions, and also drive LED lights to display and interact with users through pins. Due to the reduction in the number of pins, traditional integrated circuits cannot meet the needs of multi-functions. Therefore, a single port is required to implement multi-switch detection, as well as LED drive multiplexing technology, which can monitor multiple signal states at the same time and drive LED displays to adapt to a variety of application scenarios. Through technical means, reduce dependence on physical pins. Such as Figure 1 As shown, it is an existing multi-switch detection and LED driving circuit. The integrated circuit system detects the state of switch K1 through the PIN1 pin, detects the state of switch K2 through the PIN2 pin, and drives the LED lamp through the PIN3 pin. PIN1 is externally connected to a pull-down resistor to maintain a low level when switch K1 is in a non-conducting state, and PIN1 is shorted to VCC when switch K1 is turned on. There is a level recognition circuit 1 in the integrated circuit system, which sends the state of switch K1 to the logic circuit by detecting the input level of PIN1. PIN2 is externally connected to switch K2, and PIN2 is shorted to VCC when K2 is turned on to the S2-1 node, and PIN2 is shorted to GND when K2 is turned on to the S2-2 node. There is a level recognition circuit 2 in the integrated circuit system, which sends the state of switch K2 to the logic circuit by detecting the input level of PIN2. PIN3 is externally connected to an LED lamp, and the logic circuit of the integrated circuit system controls the LED driving circuit to output the driving level current to turn the LED lamp on and off. The existing technical solution requires two level recognition circuits and three independent pins, which increases the packaging cost of the integrated circuit system and requires a larger volume to lead out multiple pins. Summary of the invention

[0003] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide a multiple switch detection and LED driving multiplexing system that uses fewer pins to realize multiple switch detection and LED lamp driving.

[0004] According to an embodiment of the present invention, a multiple switch detection and LED drive multiplexing system includes: an integrated circuit module, a switch module and an LED lamp, wherein the integrated circuit module includes a logic circuit, an LED drive circuit, a level recognition circuit and a PIN pin, wherein the PIN pin is electrically connected to the output end of the LED drive circuit, the input end of the level recognition circuit, the output end of the switch module and the LED lamp respectively, a voltage VCC is input to the input end of the switch module, and the logic circuit controls and enables the LED drive circuit and the level recognition circuit respectively; the switch module inputs a voltage V0 to the level recognition circuit through the PIN pin, and the level recognition circuit detects the state of the switch module according to the change of the voltage V0, and feeds back the detection signal to the logic circuit, and the voltage V0 is less than the forward voltage VF of the LED lamp.

[0005] According to some embodiments of the present invention, the switch module includes a switch K1, a switch K2, a resistor R1, a resistor R2 and a resistor R3, the switch K2 includes an S2 terminal, an S2-1 terminal and an S2-2 terminal, one end of the switch K1 and the S2-1 terminal are respectively input with a voltage VCC, the other end of the switch K1 is connected in series with the resistor R1 and is electrically connected to the PIN pin, the S2 terminal is connected in series with the resistor R2 and is electrically connected to the PIN pin, the S2-2 terminal and one end of the resistor R3 are respectively grounded, and the other end of the resistor R3 is electrically connected to the PIN pin.

[0006] According to some embodiments of the present invention, when the switch K1 is disconnected and the S2 terminal of the switch K2 is connected to the S2-2 terminal, the voltage V0 of the PIN pin is equal to the voltage Vl=0V; when the switch K1 is turned on and the S2 terminal of the switch K2 is connected to the S2-2 terminal, the voltage V0 of the PIN pin is equal to the voltage Vk=the voltage VCC*(R2*R3 / (R2+R3)) / (R1+(R2*R3 / (R2+R3))); when the switch K1 is disconnected and the S2 terminal of the switch K2 is connected to the S2-1 terminal, the voltage V0 of the PIN pin is equal to the voltage Vh=the voltage VCC*R3 / (R2+R3); when the switch K1 is turned on and the S2 terminal of the switch K2 is connected to the S2-1 terminal, the voltage V0 of the PIN pin is equal to the voltage Vkh=the voltage VCC*R3 / (R3+R1*R2 / (R1+R2)).

[0007] According to some embodiments of the present invention, voltage Vkh>voltage Vh>voltage Vk, and voltage Vkh<forward voltage VF.

[0008] According to some embodiments of the present invention, the resistance value of the resistor R1 ≥ the resistance value of the resistor R2 ≥ the resistance value of the resistor R3 .

[0009] According to some embodiments of the present invention, when the voltage V0 of the PIN pin is equal to the voltage Vl, the level recognition circuit sends a 00 signal to the logic circuit; when the voltage V0 of the PIN pin is Vk, the level recognition circuit sends a 01 signal to the logic circuit; when the voltage V0 of the PIN pin is Vh, the level recognition circuit sends a 10 signal to the logic circuit; when the voltage V0 of the PIN pin is Vkh, the level recognition circuit sends an 11 signal to the logic circuit.

[0010] According to some embodiments of the present invention, the level recognition circuit includes a comparator CMP0, a comparator CMP1 and a switch SW0, the positive end of the comparator CMP0 and the positive end of the comparator CMP1 are electrically connected to the PIN pin respectively, the negative end of the comparator CMP0 inputs a reference voltage Vkrf and is electrically connected to one end of the switch SW0, the other end of the switch SW0 inputs a reference voltage Vkhrf, the negative end of the comparator CMP1 inputs a reference voltage Vhrf, the control end of the switch SW0 is electrically connected to the output end of the comparator CMP1, the output end of the comparator CMP0 outputs a signal OUT0, and the output end of the comparator CMP1 outputs a signal OUT1.

[0011] The multiple switch detection and LED drive multiplexing system according to the embodiment of the present invention has at least the following beneficial effects: the system has only one PIN pin, the LED drive circuit drives the LED lamp through the PIN pin, the level recognition circuit collects the voltage V0 generated when the switch module state changes through the PIN pin, and feeds back the detection signal to the logic circuit, and the logic circuit performs upper-layer function application after receiving the detection signal of the level recognition circuit; in order to prevent the LED lamp from being driven by the switch module, it is also necessary to limit the voltage V0 to be less than the forward voltage VF of the LED lamp. That is, there is only one PIN pin and one level recognition circuit in the system, and the PIN pin can not only drive the LED lamp, but also detect multiple states of the switch module, monitor multiple signals, and adapt to various application scenarios.

[0012] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings;

[0014] Figure 1 It is an existing multi-switch detection and LED driving circuit;

[0015] Figure 2 It is a circuit schematic diagram of the multi-switch detection and LED drive multiplexing system of the present invention;

[0016] Figure 3 It is the circuit schematic diagram of the level recognition circuit. DETAILED DESCRIPTION

[0017] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0018] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated 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.

[0019] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0020] Reference Figures 2 to 3The present invention provides a multi-switch detection and LED drive multiplexing system, including: an integrated circuit module 10, a switch module 20 and an LED lamp, the integrated circuit module 10 includes a logic circuit, an LED drive circuit, a level recognition circuit 30 and a PIN pin, the PIN pin is respectively electrically connected to the output end of the LED drive circuit, the input end of the level recognition circuit 30, the output end of the switch module 20 and the LED lamp, the input end of the switch module 20 inputs a voltage VCC, and the logic circuit controls and enables the LED drive circuit and the level recognition circuit 30 respectively; the switch module 20 inputs a voltage V0 to the level recognition circuit 30 through the PIN pin, and when the state of the switch module 20 changes, the level recognition circuit 30 is The voltage V0 input by the circuit 30 changes, and the system has a PIN pin. The LED driving circuit drives the LED lamp through the PIN pin. The level identification circuit 30 identifies the voltage V0 generated when the state of the switch module 20 changes through the PIN pin, and outputs the comparison result (detection signal) to the logic circuit by comparing the size of the voltage V0. After receiving the detection signal of the level identification circuit 30, the logic circuit performs upper-layer function application. For example, different detection signals correspond to different functions, and the logic circuit controls different functions by receiving different detection signals. In order to prevent the LED lamp from being driven by the switch module 20, it is also necessary to limit the voltage V0 to be less than the forward voltage VF of the LED lamp. That is, there is one PIN pin in the system and one level identification circuit 30. Through the PIN pin, not only can the LED lamp be driven, but also various states of the switch module 20 can be detected, multiple signals can be monitored, and it can adapt to various application scenarios.

[0021] Preferably, the switch module 20 includes at least two switches connected in parallel, and each switch is connected in series with a resistor to form at least four state combinations, so that the voltage V0 has at least four different voltage values, so that the PIN pin detects at least four signals.

[0022] like Figure 2As shown, in some embodiments, the switch module 20 includes a switch K1, a switch K2, a resistor R1, a resistor R2 and a resistor R3. The switch K2 includes an S2 terminal, an S2-1 terminal and an S2-2 terminal. One terminal of the switch K1 and the S2-1 terminal are respectively input with a voltage VCC. The other terminal of the switch K1 is connected in series with the resistor R1 and then electrically connected to the PIN pin. The S2 terminal is connected in series with the resistor R2 and then electrically connected to the PIN pin. The S2-2 terminal and one end of the resistor R3 are respectively grounded. The other end of the resistor R3 is electrically connected to the PIN pin. When the switch K1 is disconnected and the S2 terminal of the switch K2 is connected to the S2-2 terminal, the voltage V0 of the PIN pin is equal to the voltage Vl and equal to 0V; when the switch K1 is turned on and the S2 terminal of the switch K2 is connected to the S2-2 terminal, the voltage V0 of the PIN pin is equal to the voltage Vk and equal to the voltage VCC*(R2*R3 / (R2+R3)) / (R1+(R2*R3 / (R2+R3))); when the switch K1 is disconnected and the S2 terminal of the switch K2 is connected to the S2-1 terminal, the voltage V0 of the PIN pin is equal to the voltage Vh and equal to the voltage VCC*R3 / (R2+R3); when the switch K1 is turned on and the S2 terminal of the switch K2 is connected to the S2-1 terminal, the voltage V0 of the PIN pin is equal to the voltage Vkh and equal to the voltage VCC*R3 / (R3+R1*R2 / (R1+R2)). In order to better distinguish the voltage V0 input to the PIN pin in the four combinations, the voltages Vkh, Vh and Vk are made different in size. Specifically, in some embodiments, the voltage Vkh> the voltage Vh> the voltage Vk, and the voltage Vkh< the forward voltage VF (to prevent the LED lamp from being driven by the switch module 20). Accordingly, the size of the resistors R1 to R3 can be: the resistance value of the resistor R1 ≥ the resistance value of the resistor R2 ≥ the resistance value of the resistor R3.

[0023] like Figure 3, which is an implementation of the level recognition circuit 30, has the advantages of simplified devices and simple design. The level recognition circuit 30 includes a comparator CMP0, a comparator CMP1 and a switch SW0, the positive end of the comparator CMP0 and the positive end of the comparator CMP1 are electrically connected to the PIN pin respectively, the negative end of the comparator CMP0 inputs the reference voltage Vkrf and is electrically connected to one end of the switch SW0, the other end of the switch SW0 inputs the reference voltage Vkhrf, the negative end of the comparator CMP1 inputs the reference voltage Vhrf, the control end of the switch SW0 is electrically connected to the output end of the comparator CMP1, the output end of the comparator CMP0 outputs a signal OUT0, and the output end of the comparator CMP1 outputs a signal OUT1. The level recognition circuit 30 can receive the voltage V0 of the PIN pin and compare the voltage V0 with the internal reference voltage, wherein the reference voltage Vkhr = voltage Vkh-Ve1, the reference voltage Vhrf = voltage Vh-Ve2, and the reference voltage Vkrf = voltage Vk-Ve2, where the values ​​of Ve1, Ve2, and Ve3 can be equal, and finally the reference voltage Vkhrf>reference voltage Vhrf>reference voltage Vk. The level recognition circuit 30 compares the input level with the three reference voltages and outputs the result.

[0024] When the voltage V0 of the PIN pin is less than the voltage Vhrf, the comparator CMP1 compares the voltage V0 with the reference voltage Vhrf, and OUT1 outputs 0. When OUT1 is 0, the switch SW0 is turned off, and the comparator CMP2 compares the voltage V0 with the reference voltage Vkrf, and OUT0 outputs 0. When the voltage Vk is input to the PIN pin, the comparator CMP1 compares the voltage Vk with the reference Vhrf. Then OUT1 outputs 0. When OUT1 is 0, the switch SW0 is turned off, and the comparator CMP2 compares the voltage Vk with the reference voltage Vkrf, and OUT0 outputs 1. When the voltage Vh is input to the PIN pin, the comparator CMP1 compares the voltage Vh with the reference voltage Vhrf, and OUT1 outputs 1. When OUT1 is 1, the switch SW0 is turned on. Because the reference voltage Vkhrf is greater than the reference voltage Vkrf, the negative input of the comparator CMP0 is actually the reference voltage Vkhrf, and the comparator CMP2 compares the voltage Vh with the reference voltage Vkhrf, and OUT0 outputs 0. When the PIN pin inputs voltage Vkh, the comparator CMP1 compares the voltage Vkh with the reference voltage Vhrf, and OUT1 outputs 1. When OUT1 is 1, the switch SW0 is turned on. Since the reference voltage Vkhrf is greater than the reference voltage Vkrf, the negative input of the comparator CMP0 is actually the reference voltage Vkhrf, and the comparator CMP2 compares the voltage Vkh with the reference voltage Vkhrf at this time, and OUT0 outputs 1. That is, when the voltage V0 of the PIN pin = voltage Vl, the level recognition circuit 30 sends a 00 signal to the logic circuit; when the voltage V0 of the PIN pin is Vk, the level recognition circuit 30 sends a 01 signal to the logic circuit; when the voltage V0 of the PIN pin is Vh, the level recognition circuit 30 sends a 10 signal to the logic circuit; when the voltage V0 of the PIN pin is Vkh, the level recognition circuit 30 sends a 11 signal to the logic circuit.

[0025] Furthermore, the present application realizes the functions of multiple switch detection and LED drive multiplexing by means of time-division multiplexing. That is, when the logic circuit alternately controls to turn off / on the LED drive circuit, it correspondingly alternately controls to turn on / off the level recognition circuit, so that the state detection of multiple switches and the lighting of the LED lamp are performed alternately. For example, each alternating cycle includes a T1 period and a T2 period. During the T1 period, the logic circuit controls to turn off the LED drive circuit and to turn on the level recognition circuit 30, and completes the state detection of multiple switches during the T1 period; during the T2 period, the logic circuit controls to turn off the level recognition circuit 30 and to turn on the LED drive circuit, and the system drives the LED lamp to light up and display during the T2 time period. The alternating cycle is relatively short. Due to the principle of visual persistence of the human eye, the human eye will not observe that the LED lamp is extinguished during the T1 period, thereby achieving the effect of the LED lamp being continuously bright.

[0026] The LED driving circuit is integrated in the integrated circuit module 10. The LED driving circuit is controlled by the logic circuit. When the LED lamp needs to be lit, the logic circuit controls the LED driving circuit to output a level to drive the LED lamp. Specifically, it can be divided into a high level or current sinking mode and a low level or current pulling mode, so that the LED lamp has a working current to light up. The LED driving circuit is relatively conventional and can adopt existing driving circuit technology.

[0027] It is easy for those skilled in the art to understand that the above preferred embodiments can be freely combined and superimposed without conflict.

[0028] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or directly or indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A multi-switch detection and LED drive multiplexing system, characterized in that: include: An integrated circuit module (10), a switch module (20) and an LED lamp, wherein the integrated circuit module (10) comprises a logic circuit, an LED driving circuit, a level recognition circuit (30) and a PIN pin, wherein the PIN pin is respectively electrically connected to an output end of the LED driving circuit, an input end of the level recognition circuit (30), an output end of the switch module (20) and the LED lamp, a voltage VCC is input to the input end of the switch module (20), and the logic circuit controls and enables the LED driving circuit and the level recognition circuit (30); The switch module (20) inputs a voltage V0 to the level recognition circuit (30) via the PIN pin; the level recognition circuit (30) detects the state of the switch module (20) according to a change in the voltage V0, and feeds back a detection signal to the logic circuit; the voltage V0 is less than a forward voltage VF of the LED lamp, thereby preventing the LED lamp from being driven by the switch module.

2. The multi-switch detection and LED drive multiplexing system according to claim 1, characterized in that: The switch module (20) comprises a switch K1, a switch K2, a resistor R1, a resistor R2 and a resistor R3; the switch K2 comprises an S2-1 terminal, an S2-2 terminal and an S2 terminal; the S2-1 terminal and the S2 terminal are electrically conductive, and the S2-2 terminal and the S2 terminal are electrically conductive; one end of the switch K1 and the S2-1 terminal are respectively input with a voltage VCC; the other end of the switch K1 is connected in series with the resistor R1 and then electrically connected to the PIN pin; the S2 terminal is connected in series with the resistor R2 and then electrically connected to the PIN pin; the S2-2 terminal and one end of the resistor R3 are respectively grounded; and the other end of the resistor R3 is electrically connected to the PIN pin.

3. The multi-switch detection and LED drive multiplexing system according to claim 2, characterized in that: When the switch K1 is disconnected and the S2 terminal and the S2-2 terminal of the switch K2 are connected, the voltage V0 of the PIN pin = the voltage V1 = 0V; When the switch K1 is turned on and the S2 terminal and the S2-2 terminal of the switch K2 are turned on, the voltage V0 of the PIN pin is Voltage Vk = voltage VCC*(R2*R3 / (R2+R3)) / (R1+(R2*R3 / (R2+R3))); When the switch K1 is disconnected and the S2 terminal and the S2-1 terminal of the switch K2 are connected, the voltage V0 of the PIN pin = the voltage Vh = the voltage VCC*R3 / (R2+R3); When the switch K1 is turned on and the S2 terminal and the S2-1 terminal of the switch K2 are turned on, the voltage V0 of the PIN pin = the voltage Vkh = the voltage VCC*R3 / (R3+R1*R2 / (R1+R2)).

4. The multi-switch detection and LED drive multiplexing system according to claim 3, characterized in that: Voltage Vkh>voltage Vh>voltage Vk, and voltage Vkh<forward voltage VF.

5. The multi-switch detection and LED drive multiplexing system according to claim 4, characterized in that: The resistance value of the resistor R1 ≥ the resistance value of the resistor R2 ≥ the resistance value of the resistor R3.

6. The multi-switch detection and LED driving multiplexing system according to claim 3, characterized in that: When the voltage V0 of the PIN pin is equal to the voltage V1, the level recognition circuit (30) sends a 00 signal to the logic circuit; when the voltage V0 of the PIN pin is the voltage Vk, the level recognition circuit (30) sends a 01 signal to the logic circuit; when the voltage V0 of the PIN pin is the voltage Vh, the level recognition circuit (30) sends a 10 signal to the logic circuit; when the voltage V0 of the PIN pin is the voltage Vkh, the level recognition circuit (30) sends an 11 signal to the logic circuit.

7. The multiple switch detection and LED driving multiplexing system according to claim 6, characterized in that: The level recognition circuit (30) comprises a comparator CMP0, a comparator CMP1 and a switch SW0, wherein the positive end of the comparator CMP0 and the positive end of the comparator CMP1 are electrically connected to the PIN pin respectively, the negative end of the comparator CMP0 inputs a reference voltage Vkrf and is electrically connected to one end of the switch SW0, the other end of the switch SW0 inputs a reference voltage Vkhrf, the negative end of the comparator CMP1 inputs a reference voltage Vhrf, the control end of the switch SW0 is electrically connected to the output end of the comparator CMP1, the output end of the comparator CMP0 outputs a signal OUT0, and the output end of the comparator CMP1 outputs a signal OUT1.

8. The multi-switch detection and LED driving multiplexing system according to claim 1, characterized in that: When the logic circuit alternately controls to turn off / on the LED driving circuit, it correspondingly alternately controls to turn on / off the level identification circuit, so that the state detection of the multiple switches and the lighting of the LED lamps are performed alternately.

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