LED drive circuit, chip and device

Abstract

The utility model provides an LED driving circuit, a chip and equipment, and relates to the field of CMOS technology circuits, and the LED driving circuit comprises a signal output end which is used for connecting a first LED and a second LED in parallel, the first LED is driven to emit light under positive voltage conduction signals, and the second LED is driven to emit light under negative voltage conduction signals; a first output end of the control module is used for outputting a first control signal, and a second output end is used for outputting a second control signal; the input end of the positive voltage module is connected to the power end, the output end is connected to the signal output end, and the control end is connected to the first output end of the control module; the input end of the negative voltage module is connected to the power end and the grounding end, the output end is connected to the signal output end, and the control end is connected to the second control end of the control module. According to the invention, the number of pins is reduced, and the routing and packaging cost of the chip is reduced.

Description

Technical Field

[0001] The utility model relates to the field of CMOS process circuits, and in particular to an LED drive circuit, a chip and a device. Background Art

[0002] LED (Light Emitting Diode) is a semiconductor device that has the characteristic of converting electrical energy into visible light. Due to the advantages of low power supply voltage, low power, simple driving method and fast response, LED has been gradually widely used in applications such as button indicator lights and charger indicator lights. With the continuous advancement of technology, LED has become a common indicator light in modern electronic products, such as charger indicator lights and electrical switch indicator lights. LED is widely used in these applications, replacing traditional indicator lights, which is conducive to energy saving and has a long service life.

[0003] The traditional lighting solution is that the chip outputs a positive voltage greater than the LED light turn-on voltage through an input / output pin to turn on the light. However, this solution can only turn on one lamp with one input / output pin. The traditional way to turn on two lamps is as follows Figure 1 As shown, it includes two input-output pins, namely a first input-output pin 11 and a second input-output pin 12, a positive voltage generating circuit 13, a positive voltage generating circuit 14 and a control circuit 15. The two positive voltage generating circuits respectively correspond to their respective pins and LED lamps, that is, each positive voltage generating circuit corresponds to one pin and one LED lamp.

[0004] In the above solution, each LED lamp requires an input and output pin. When multiple lamps are needed, a corresponding number of pins are required, which will be limited when the number of chip pins is limited. Moreover, as the number of pins increases, the system wiring and control circuits become more complicated, increasing the cost of design and maintenance. Utility Model Content

[0005] Based on the above situation, the main purpose of the utility model is to provide an LED driving circuit, chip and equipment to save the number of pins and reduce the wiring and packaging costs of the chip.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0007] In a first aspect, an embodiment of the utility model discloses an LED driving circuit, comprising:

[0008] A signal output terminal, used for connecting a first LED and a second LED in parallel, wherein the first LED is driven to emit light under a positive voltage conduction signal, and the second LED is driven to emit light under a negative voltage conduction signal;

[0009] A control module, wherein a first output terminal of the control module is used to output a first control signal, and a second output terminal of the control module is used to output a second control signal, wherein the first control signal and the second control signal are output in a time-sharing manner;

[0010] A positive pressure module, whose input end is connected to the power supply end, the output end of the positive pressure module is connected to the signal output end, and the control end of the positive pressure module is connected to the first output end of the control module; the positive pressure module drives the output end of the positive pressure module to output the positive pressure conduction signal in response to the first control signal received by the control end of the positive pressure module;

[0011] A negative pressure module, whose input end is connected to the power supply end and the ground end, the output end of the negative pressure module is connected to the signal output end, and the control end of the negative pressure module is connected to the second control end of the control module; the negative pressure module drives the output end of the negative pressure module to output the negative pressure conduction signal in response to the second control signal received by its control end.

[0012] Preferably, in response to receiving the first control signal at its control end, the positive pressure module drives the output end of the negative pressure module to output a negative pressure shutoff signal to shut off the second LED;

[0013] In response to receiving the second control signal at its control end, the negative pressure module drives the output end of the positive pressure module to output a positive pressure shutoff signal to shut off the first LED.

[0014] Preferably, the positive pressure module comprises a first transistor, a first electrode of which is connected to the power supply end, a second electrode of the first transistor is connected to the signal output end, and a control electrode of the first transistor is connected to the first output end of the control module.

[0015] Preferably, the first transistor is a PMOS transistor.

[0016] Preferably, the negative pressure module comprises a charge transfer unit, a first phase unit and a second phase unit, one end of the charge transfer unit is connected to the low potential output end of the first phase unit and the high potential output end of the second phase unit, and one end of the charge transfer unit is connected to the high potential output end of the first phase unit and the low potential output end of the second phase unit;

[0017] The control end of the first phase unit is connected to the second control end of the control module, the control end of the second phase unit is connected to the second control end of the control module, and the output end of the second phase unit is connected to the signal output end;

[0018] The first phase unit and the second phase unit drive the output end of the second phase unit to output the negative voltage conduction signal in response to the received second control signal.

[0019] Preferably, the control ends of the first phase unit and the second phase unit receive the second control signal and alternately turn on and drive the output end of the second phase unit to output the negative voltage turn-on signal.

[0020] Preferably, the charge transfer unit includes a first capacitor, one end of the first capacitor is connected to the low potential output end of the first phase unit and the high potential output end of the second phase unit through a first node, and one end of the first capacitor is connected to the high potential output end of the first phase unit and the low potential output end of the second phase unit through a second node.

[0021] Preferably, the first phase unit comprises a second transistor and a fourth transistor, the first electrode of the second transistor is connected to the power supply end, the second electrode of the second transistor is connected to the first node, and the control electrode of the second transistor is connected to the second output end of the control module;

[0022] A first electrode of the fourth transistor is connected to the ground terminal, a second electrode of the fourth transistor is connected to the second node, and a control electrode of the fourth transistor is connected to the second output terminal of the control module.

[0023] Preferably, the second transistor is a PMOS transistor, and the fourth transistor is an NMOS transistor.

[0024] Preferably, the second phase unit comprises a third transistor and a fifth transistor, the first electrode of the third transistor is connected to the ground terminal, the second electrode of the third transistor is connected to the first node, and the control electrode of the third transistor is connected to the second output terminal of the control module;

[0025] A first electrode of the fifth transistor is connected to the signal output terminal, a second electrode of the fifth transistor is connected to the second node, and a control electrode of the fifth transistor is connected to the second output terminal of the control module.

[0026] Preferably, the third transistor and the fifth transistor are both NMOS transistors.

[0027] Preferably, the negative pressure module also includes a voltage stabilizing and filtering module, which includes a second capacitor, one end of which is connected to the ground terminal, and one end of which is connected to the first electrode of the fifth transistor and the signal output terminal connecting branch.

[0028] In a second aspect, an embodiment of the utility model discloses an LED driver chip having an integrated circuit thereon, wherein the integrated circuit is designed to be an LED driver circuit as described in any one of the above items.

[0029] In a third aspect, an embodiment of the utility model discloses a device with an LED driver, comprising: an LED driver circuit as described in any one of the above.

[0030] According to an LED driving circuit, chip and device disclosed in the utility model, a control module outputs a positive pressure module control signal and a negative pressure module control signal, thereby realizing the control of lighting two LED lamps on one input and output pin. By reusing one pin for two LEDs, the number of pins is saved and the wiring and packaging costs of the chip are reduced. In addition, the control module, the positive pressure module and the negative pressure module are integrated, which simplifies the wiring and control circuit of the system and reduces the design and maintenance costs. By flexibly outputting positive pressure signals and negative pressure signals through the control module, independent control of the two LEDs is realized, thereby enhancing the flexibility of the system and the ability to cope with complex control requirements.

[0031] Other beneficial effects of the utility model will be explained through the introduction of specific technical features and technical solutions in the specific implementation manner. Through the introduction of these technical features and technical solutions, those skilled in the art should be able to understand the beneficial technical effects brought about by the technical features and technical solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The following will describe a preferred embodiment of an LED driving circuit, chip and device of the present invention with reference to the accompanying drawings.

[0033] Figure 1 This is a structural diagram of the traditional implementation method of lighting two lamps;

[0034] Figure 2 A circuit diagram of an LED driving circuit disclosed in this embodiment;

[0035] Figure 3 This is a topological schematic diagram of the connection between an input and output pin and a first LED and a second LED disclosed in this embodiment. DETAILED DESCRIPTION

[0036] The present invention is described below based on embodiments, but the present invention is not limited to these embodiments. In the following detailed description of the present invention, some specific details are described in detail. In order to avoid confusing the essence of the present invention, known methods, processes, procedures, and components are not described in detail.

[0037] In addition, persons of ordinary skill in the art will appreciate that the drawings provided herein are for illustration purposes and are not necessarily drawn to scale.

[0038] Unless the context clearly requires otherwise, throughout the specification and claims, the words "include", "comprising" and similar words should be interpreted in an inclusive sense rather than an exclusive or exhaustive sense; that is, in the sense of "including but not limited to".

[0039] In the description of the present invention, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0040] In order to save the number of pins and reduce the wiring and packaging costs of the chip, this embodiment discloses an LED driving circuit. Figure 2 , Figure 2 This embodiment discloses an LED driving circuit, which includes: a signal output terminal VOUT, a control module 1, a positive pressure module 2 and a negative pressure module 3, wherein:

[0041] The signal output terminal VOUT is used to connect the first LED and the second LED in parallel. The first LED is driven to emit light under a positive voltage conduction signal, and the second LED is driven to emit light under a negative voltage conduction signal. The signal output terminal VOUT can connect the first LED and the second LED in parallel through the input and output pin 8 (IO pin), such as Figure 3 As shown, the positive end of the first LED (LED1) is connected to the input-output pin 8 (IO pin), and the negative end is grounded; the positive end of the second LED (LED2) is grounded, and the negative end is connected to the input-output pin 8 (IO pin). Therefore, the first LED can be driven to emit light using a positive voltage conduction signal, and the second LED can be driven to emit light using a negative voltage conduction signal.

[0042] The first output terminal of the control module 1 is used to output a first control signal, and the second output terminal of the control module 1 is used to output a second control signal, wherein the first control signal and the second control signal are output in time-sharing. The control module 1 outputs the first control signal and the second control signal in time-sharing to control the first LED and the second LED to not light up at the same time.

[0043] The input end of the positive pressure module 2 is connected to the power supply end AVDD, the output end of the positive pressure module 2 is connected to the signal output end VOUT, and the control end of the positive pressure module 2 is connected to the first output end of the control module 1; the positive pressure module 2 drives the output end of the positive pressure module 2 to output a positive pressure conduction signal in response to the first control signal received by its control end;

[0044] The input end of the negative pressure module 3 is connected to the power supply end AVDD and the ground end, the output end of the negative pressure module 3 is connected to the signal output end VOUT, and the control end of the negative pressure module 3 is connected to the second control end of the control module 1; the negative pressure module 3 drives the output end of the negative pressure module 3 to output a negative pressure conduction signal in response to the second control signal received by its control end.

[0045] In this embodiment, the control module outputs the positive pressure module control signal and the negative pressure module control signal, thereby controlling the lighting of two LED lamps on one input and output pin. By reusing one pin for two LEDs, the number of pins is saved and the wiring and packaging costs of the chip are reduced. In addition, the control module, the positive pressure module and the negative pressure module are integrated to simplify the system wiring and control circuits and reduce the design and maintenance costs. The control module flexibly outputs the positive pressure conduction signal and the negative pressure conduction signal to achieve independent control of the two LEDs, thereby enhancing the flexibility of the system and the ability to cope with complex control requirements.

[0046] Specifically, in response to receiving the first control signal at its control end, the positive pressure module 2 drives the output end of the negative pressure module 3 to output a negative pressure shutoff signal to shut off the second LED;

[0047] In response to receiving the second control signal at its control end, the negative pressure module 3 drives the output end of the positive pressure module 2 to output a positive pressure shutoff signal to shut off the first LED.

[0048] In this embodiment, when lighting the first LED, the control module 1 outputs a first control signal to drive the positive pressure module 2 to output a positive pressure conduction signal to turn on the first LED, and drives the negative pressure module 3 to output a negative pressure shutoff signal to turn off the second LED, and the input-output pin 8 will output a positive voltage greater than the first LED turn-on voltage to light up the first LED. When lighting the second LED, the control module 1 outputs a second control signal to drive the positive pressure module 2 to output a positive pressure shutoff signal to turn off the first LED, and drives the negative pressure module 3 to output a negative pressure conduction signal to turn on the second LED, and the input-output pin 8 will output a negative pressure, and the absolute value of the negative pressure is greater than the turn-on voltage of the second LED to light up the second LED. By using the principle of time-sharing multiplexing, a single input-output pin can light two lamps, realize independent control of the two LED lamps, and reduce the number of pins.

[0049] Specific as Figure 2 As shown, the positive voltage module 2 includes a first transistor MP1 , a first electrode of which is connected to the power supply terminal AVDD, a second electrode of the first transistor MP1 is connected to the signal output terminal VOUT, and a control electrode of the first transistor MP1 is connected to the first output terminal of the control module 1 .

[0050] The first electrode of the first transistor MP1 is a source electrode, the second electrode of the first transistor MP1 is a drain electrode, and the control electrode of the first transistor MP1 is a gate electrode. The first control signal can be input through the third electrode as a PH5 control signal. The PH5 control signal is a low-level signal to turn on the first transistor MP1, that is, to connect the signal output terminal VOUT to the power supply terminal AVDD, so that the voltage of the signal output terminal VOUT is equal to the AVDD voltage value. In this way, the input-output pin 8 will also be affected by the voltage AVDD, and the voltage is in a positive high-level state. Therefore, the input-output pin 8 will output a positive voltage turn-on signal to drive the first LED to turn on.

[0051] Wherein, the first transistor MP1 is preferably a PMOS transistor. It can also be an NMOS transistor. Compared with the PMOS transistor, the PH5 control signal that turns on the NMOS transistor is a high-level signal. In addition, the efficiency of NMOS is not that high. If it is a PMOS transistor, the voltage VOUT is basically equal to AVDD. If it is an NMOS transistor, the voltage VOUT will be reduced by a threshold voltage (gate-source voltage). The gate-source voltage is the minimum voltage required for the NMOS transistor to turn on, and there will be a voltage drop between the gate and the source when the NMOS is turned on, which will cause the voltage of VOUT to be slightly lower than AVDD, and may not reach the voltage to turn on the first LED. Therefore, the PMOS transistor is more efficient than the NMOS transistor and can generate a positive voltage that turns on the first LED.

[0052] In a preferred embodiment, Figure 2 As shown, the negative pressure module 3 includes a charge transfer unit 4, a first phase unit 5 and a second phase unit 6, one end of the charge transfer unit 4 is connected to the low potential output end of the first phase unit 5 and the high potential output end of the second phase unit 6, and one end of the charge transfer unit 4 is connected to the high potential output end of the first phase unit 5 and the low potential output end of the second phase unit 6.

[0053] The control end of the first phase unit 5 is connected to the second control end of the control module 1, the control end of the second phase unit 6 is connected to the second control end of the control module 1, and the output end of the second phase unit 6 is connected to the signal output end VOUT;

[0054] The first phase unit 5 and the second phase unit 6 drive the output end of the second phase unit 6 to output a negative voltage conduction signal in response to the received second control signal.

[0055] Specifically, the control ends of the first phase unit 5 and the second phase unit 6 receive the second control signal and alternately turn on and drive the output end of the second phase unit 6 to output a negative voltage conduction signal.

[0056] Since the charge transfer unit 4 is required to realize the charge transfer to the signal output terminal VOUT, and since the capacitor voltage cannot change suddenly, the first phase unit 5 and the second phase unit 6 are required to be alternately turned on to drive the output terminal of the second phase unit 6 to output a negative voltage turn-on signal to turn on the second LED.

[0057] Further, the charge transfer unit 4 includes a first capacitor C1, wherein one end of the first capacitor C1 is connected to the low potential output end of the first phase unit 5 and the high potential output end of the second phase unit 6 through the first node VP, and one end of the first capacitor C1 is connected to the high potential output end of the first phase unit 5 and the low potential output end of the second phase unit 6 through the second node VN.

[0058] Specifically, the first capacitor C1 can be used to store charges and transfer the charges to the signal output terminal VOUT. The first phase unit 5 can be used to charge the first capacitor C1 to store charges, and then the second phase unit 6 can be used to discharge the first capacitor C1 to transfer the charges to the signal output terminal VOUT, so as to turn on the first LED.

[0059] Specific as Figure 2 As shown, the first phase unit 5 includes a second transistor MP2 and a fourth transistor MN2, the first electrode of the second transistor is connected to the power supply terminal AVDD, the second electrode of the second transistor is connected to the first node VP, and the control electrode of the second transistor is connected to the second output terminal of the control module 1; the first electrode of the fourth transistor MN2 is connected to the ground terminal, the second electrode of the fourth transistor MN2 is connected to the second node VN, and the control electrode of the fourth transistor MN2 is connected to the second output terminal of the control module 1.

[0060] The first electrode of the second transistor MP2 is the source, the second electrode of the second transistor MP2 is the drain (i.e. the low potential output terminal mentioned above), and the control electrode of the second transistor MP2 is the gate; the first electrode of the fourth transistor MN2 is the source, the second electrode of the fourth transistor MN2 is the drain (i.e. the high potential output terminal mentioned above), and the control electrode of the fourth transistor MN2 is the gate.

[0061] The second transistor MP2 is preferably a PMOS transistor, and the fourth transistor MN2 is preferably an NMOS transistor.

[0062] PMOS transistors are used to transmit high-voltage signals, while NMOS transistors are used to transmit low-voltage signals to improve the efficiency and performance of the circuit. The design of the negative voltage generation module is achieved by mixing NMOS and PMOS transistors, which helps to minimize the on-resistance, save the voltage drop between the gate and the source, and improve the efficiency and performance of the circuit.

[0063] like Figure 2As shown, the second phase unit 6 includes a third transistor MN1 and a fifth transistor MN3, the first electrode of the third transistor MN1 is connected to the ground terminal, the second electrode of the third transistor MN1 is connected to the first node VP, and the control electrode of the third transistor MN1 is connected to the second output terminal of the control module 1;

[0064] A first electrode of the fifth transistor MN3 is connected to the signal output terminal VOUT, a second electrode of the fifth transistor MN3 is connected to the second node VN, and a control electrode of the fifth transistor MN3 is connected to the second output terminal of the control module 1 .

[0065] The first electrode of the third transistor MN1 is the source, the second electrode of the third transistor MN1 is the drain (i.e. the high potential output terminal mentioned above), and the control electrode of the third transistor MN1 is the gate; the first electrode of the fifth transistor MN3 is the source, the second electrode of the fifth transistor MN3 is the drain (i.e. the low potential output terminal mentioned above), and the control electrode of the fifth transistor MN3 is the gate.

[0066] The third transistor MN1 and the fifth transistor MN3 are preferably NMOS transistors.

[0067] The second phase unit 6 selects an NMOS transistor as the preferred device for the third and fifth transistors to discharge the capacitor. The second phase unit 6 is used to discharge the first capacitor C1 to transfer the charge to the signal output terminal VOUT, thereby turning on the first LED. The NMOS transistor can provide efficient energy release, low-loss discharge process, and has flexible control performance.

[0068] The negative pressure module 3 also includes a voltage stabilizing filter module 7, which includes a second capacitor C2, one end of which is connected to the ground end, and one end of which is connected to the first electrode of the fifth transistor MN3 and the signal output end VOUT connection branch.

[0069] When the second phase unit 6 is used to discharge the first capacitor C1 to transfer the charge to the signal output terminal VOUT, the high-frequency noise or interference in the output negative voltage signal can be filtered out by connecting the second capacitor C2, so that a relatively stable and pure output signal is obtained at the signal output terminal VOUT, thereby improving the quality and stability of the output signal. The second capacitor C2 can also help stabilize the voltage of the signal output terminal VOUT, reduce voltage fluctuations, and improve the stability and reliability of the circuit. In particular, when there are fluctuations or ripples in the input signal, the second capacitor C2 can smooth the voltage waveform and reduce the impact of noise on the system.

[0070] According to the specific circuit structures of the positive pressure module 2 and the negative pressure module 3, the specific working principle of the control module 1 outputting the first control signal and the second control signal to drive the first LED or the second LED to turn on is:

[0071] When the driver turns on the first LED:

[0072] The first control signal is input to the positive voltage module 2, and the PH5 control signal is input through the third electrode of the first transistor MP1. The PH5 control signal is a low-level signal to turn on the first transistor MP1, that is, the signal output terminal VOUT is connected to the power supply terminal AVDD, so that the voltage of the signal output terminal VOUT is equal to the AVDD voltage value. In this way, the input-output pin 8 will also be affected by the voltage AVDD, and the voltage is in a positive high-level state. Therefore, the input-output pin 8 will output a positive voltage conduction signal to drive the first LED to turn on.

[0073] At the same time, the positive pressure module 2 drives the negative pressure module 3 to output a negative pressure shutdown signal in response to receiving the first control signal: the PH1 control signal, the PH2 control signal, the PH3 control signal and the PH4 control signal are input through the third electrodes of the second transistor MP2, the third transistor MN1, the fourth transistor MN2 and the fifth transistor MN3 respectively, the PH1 control signal is a high level signal, the PH2 control signal, the PH3 control signal and the PH4 control signal are all low level signals, so that the second transistor MP2, the third transistor MN1, the fourth transistor MN2 and the fifth transistor MN3 are all turned off, thereby driving the second LED to be turned off.

[0074] When the driver turns on the second LED:

[0075] The second control signal is input to the negative voltage module 3. First, in the phase 1 stage, the PH1 control signal, PH2 control signal, PH3 control signal and PH4 control signal are input through the third electrodes of the second transistor MP2, the third transistor MN1, the fourth transistor MN2 and the fifth transistor MN3 respectively. The PH1 control signal, the PH2 control signal and the PH4 control signal are low-level signals, and the PH3 control signal is a high-level signal, so that the second transistor MP2 of the first phase unit 5 and the fourth transistor MN2 are turned on, and the third transistor MN1 and the fifth transistor MN3 of the second phase unit 6 are turned off; thereby, the power supply terminal AVDD of the second transistor MP2 can be connected to one end of the first capacitor C1 through the first node VP, and the ground terminal of the fourth transistor MN2 is connected to one end of the first capacitor C1 through the second node VN, forming a path, the voltage of the second node VN is zero, and the power supply terminal AVDD transfers the charge to the first capacitor C1 through the first node VP to charge it, so that the voltage across the first capacitor is AVDD, and the charging of the capacitor C1 can be realized;

[0076] Then, in the phase 2 stage, the PH1 control signal, PH2 control signal, PH3 control signal and PH4 control signal are input through the third electrodes of the second transistor MP2, the third transistor MN1, the fourth transistor MN2 and the fifth transistor MN3 respectively. The PH1 control signal, the PH2 control signal and the PH4 control signal are all high-level signals, and the PH3 control signal is a low-level signal, so that the second transistor MP2 and the fourth transistor MN2 are turned off, and the third transistor MN1 and the fifth transistor MN3 are turned on; thereby, the ground terminal of the third transistor MN1 can be connected to one end of the first capacitor C1 through the first node VP, and one end of the fifth transistor MN3 is connected to one end of the first capacitor C1 through the second node VN, forming a path, the voltage of the first node VP is pulled down to zero, the first capacitor C1 is in a fully charged state, and the conduction of the fifth transistor MN3 can discharge the first capacitor C1, and the current can only return through the ground terminal loop, thereby forming a negative voltage, so that the voltage of the second node VN is -AVDD, so the input-output pin 8 will output a negative voltage turn-on signal to drive the second LED to turn on.

[0077] At the same time, the negative pressure module 3 responds to receiving the second control signal to drive the positive pressure module 2 to output a positive pressure shutdown signal: a PH5 control signal is input through the third electrode of the first transistor MP1, and the PH5 control signal is a high level signal to turn off the first transistor MP1, thereby driving the first LED to turn off.

[0078] In other preferred embodiments, the circuit of the negative pressure module 3 only needs to realize the charging and discharging of the capacitor so as to finally output a negative pressure conduction signal, which will not be described in detail here.

[0079] In addition, this embodiment further provides an LED driver chip, wherein the chip has an integrated circuit, and the integrated circuit is designed as the LED driver circuit disclosed in the above embodiment.

[0080] This embodiment also discloses a device with LED driving, wherein the device includes the LED driving circuit disclosed in the above embodiment.

[0081] According to an LED driving circuit, chip and device disclosed in the utility model, a control module outputs a positive pressure module control signal and a negative pressure module control signal, thereby realizing the control of lighting two LED lamps on one input and output pin. By reusing one pin for two LEDs, the number of pins is saved and the wiring and packaging costs of the chip are reduced. In addition, the control module, the positive pressure module and the negative pressure module are integrated, which simplifies the wiring and control circuit of the system and reduces the design and maintenance costs. By flexibly outputting positive pressure signals and negative pressure signals through the control module, independent control of the two LEDs is realized, thereby enhancing the flexibility of the system and the ability to cope with complex control requirements.

[0082] It will be appreciated by those skilled in the art that, under the premise of no conflict, the above-mentioned preferred solutions can be freely combined and superimposed. Among them, the flowcharts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, a program segment, or a part of a code, and the module, program segment, or a part of a code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings, for example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions. The numbering of each step in this article is only for the convenience of description and reference, and is not used to limit the order of execution. The specific execution order is determined by the technology itself, and those skilled in the art can determine various allowable and reasonable orders based on the technology itself.

[0083] Those skilled in the art will appreciate that, without conflict, the above-mentioned preferred solutions can be freely combined and superimposed.

[0084] It should be understood that the above-mentioned embodiments are merely illustrative and not restrictive. Without departing from the basic principles of the present invention, various obvious or equivalent modifications or substitutions that can be made by technicians in this field to the above details will be included in the scope of the claims of the present invention.

Claims

1. An LED driving circuit, characterized in that: include: A signal output terminal (VOUT), used for connecting a first LED and a second LED in parallel, wherein the first LED is driven to emit light under a positive voltage conduction signal, and the second LED is driven to emit light under a negative voltage conduction signal; A control module, wherein a first output terminal of the control module is used to output a first control signal, and a second output terminal of the control module is used to output a second control signal, wherein the first control signal and the second control signal are output in a time-sharing manner; A positive pressure module, whose input end is connected to the power supply end (AVDD), the output end of the positive pressure module is connected to the signal output end (VOUT), and the control end of the positive pressure module is connected to the first output end of the control module; the positive pressure module drives the output end of the positive pressure module to output the positive pressure conduction signal in response to the first control signal received by the control end of the positive pressure module; A negative pressure module, whose input end is connected to the power supply end (AVDD) and the ground end, the output end of the negative pressure module is connected to the signal output end (VOUT), and the control end of the negative pressure module is connected to the second control end of the control module; the negative pressure module drives the output end of the negative pressure module to output the negative pressure conduction signal in response to the second control signal received by its control end.

2. The LED driving circuit according to claim 1, characterized in that: The positive pressure module drives the output end of the negative pressure module to output a negative pressure shutoff signal in response to the control end thereof receiving the first control signal, so as to shut off the second LED; In response to receiving the second control signal at its control end, the negative pressure module drives the output end of the positive pressure module to output a positive pressure shutoff signal to shut off the first LED.

3. The LED driving circuit according to claim 1, characterized in that: The positive voltage module comprises a first transistor (MP1), a first electrode of which is connected to the power supply terminal (AVDD), a second electrode of the first transistor (MP1) is connected to the signal output terminal (VOUT), and a control electrode of the first transistor (MP1) is connected to the first output terminal of the control module.

4. The LED driving circuit according to claim 3, characterized in that: The first transistor (MP1) is a PMOS transistor.

5. The LED driving circuit according to claim 1, characterized in that: The negative pressure module comprises a charge transfer unit, a first phase unit and a second phase unit, one end of the charge transfer unit is connected to the low potential output end of the first phase unit and the high potential output end of the second phase unit, and one end of the charge transfer unit is connected to the high potential output end of the first phase unit and the low potential output end of the second phase unit; The control end of the first phase unit is connected to the second control end of the control module, the control end of the second phase unit is connected to the second control end of the control module, and the output end of the second phase unit is connected to the signal output end (VOUT); The first phase unit and the second phase unit drive the output end of the second phase unit to output the negative voltage conduction signal in response to the received second control signal.

6. The LED driving circuit according to claim 5, characterized in that: The control ends of the first phase unit and the second phase unit receive the second control signal and alternately turn on and drive the output end of the second phase unit to output the negative voltage conduction signal.

7. The LED driving circuit according to claim 5, characterized in that: The charge transfer unit comprises a first capacitor (C1), one end of the first capacitor (C1) is connected to a low potential output end of the first phase unit and a high potential output end of the second phase unit via a first node (VP), and one end of the first capacitor (C1) is connected to a high potential output end of the first phase unit and a low potential output end of the second phase unit via a second node (VN).

8. The LED driving circuit according to claim 7, characterized in that: The first phase unit comprises a second transistor (MP2) and a fourth transistor (MN2), a first electrode of the second transistor is connected to the power supply terminal (AVDD), a second electrode of the second transistor is connected to the first node (VP), and a control electrode of the second transistor is connected to a second output terminal of the control module; A first electrode of the fourth transistor (MN2) is connected to the ground terminal, a second electrode of the fourth transistor (MN2) is connected to the second node (VN), and a control electrode of the fourth transistor (MN2) is connected to the second output terminal of the control module.

9. The LED driving circuit according to claim 8, characterized in that: The second transistor (MP2) is a PMOS transistor, and the fourth transistor (MN2) is an NMOS transistor.

10. The LED driving circuit according to claim 7, characterized in that: The second phase unit comprises a third transistor (MN1) and a fifth transistor (MN3), a first electrode of the third transistor (MN1) is connected to the ground terminal, a second electrode of the third transistor (MN1) is connected to the first node (VP), and a control electrode of the third transistor (MN1) is connected to the second output terminal of the control module; A first electrode of the fifth transistor (MN3) is connected to the signal output terminal (VOUT), a second electrode of the fifth transistor (MN3) is connected to the second node (VN), and a control electrode of the fifth transistor (MN3) is connected to the second output terminal of the control module.

11. The LED driving circuit according to claim 10, characterized in that: The third transistor (MN1) and the fifth transistor (MN3) are both NMOS transistors.

12. The LED driving circuit according to claim 10, characterized in that: The negative pressure module also includes a voltage stabilizing filter module, which includes a second capacitor (C2), one end of the second capacitor (C2) is connected to the ground end, and one end of the second capacitor (C2) is connected to the first electrode of the fifth transistor (MN3) and the signal output end (VOUT) connection branch.

13. An LED driver chip having an integrated circuit thereon, characterized in that: The integrated circuit is designed as the LED driving circuit as claimed in any one of claims 1-12.

14. A device having an LED driver, characterized in that: include: The LED driving circuit according to any one of claims 1 to 12.

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