LED constant current driving circuit structure with wide working voltage

Abstract

The application relates to an LED constant current driving circuit structure for realizing wide working voltage, which comprises a band-gap reference voltage circuit module for generating a bias voltage and a zero-temperature-coefficient reference voltage; a PTAT current generating circuit module for generating an output current through an enabling signal, the reference voltage and the bias voltage; an LED mirror current module for generating multiple sets of bias currents through a current mirror structure; and eight LED constant current source circuit modules for receiving the bias currents respectively and driving LED lamps. The LED constant current driving circuit structure for realizing wide working voltage can provide constant LED driving current, and the current can be adjusted. The application adopts a 5V tube design, can provide constant LED driving current in a wide working voltage range, and does not need an LDO for voltage stabilization when working. The LED constant current source driving circuit can not only output LED driving current, but also serve as a common cathode COM port during LED scanning and bear a filling current of more than 110mA.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of integrated circuits, in particular to the field of LED driving circuit, and more particularly to an LED constant current driving circuit structure for realizing wide working voltage. BACKGROUND

[0002] As a new type of light source, LED has the characteristics of energy saving, environmental protection and high efficiency, and is widely used in lighting, display and other fields. As a constant current load, LED has strict requirements on working voltage. High or low voltage will affect the working performance of LED. In different application environments, the power voltage will fluctuate. In order to ensure that the LED has better performance and longer working life, the LED driving circuit is generally designed as constant current driving.

[0003] The traditional AC / DC or DC / DC constant voltage control cannot achieve constant current driving, and will also affect the brightness and service life of LED. At present, in the application of direct current low voltage power supply, such as lithium battery, lead-acid battery and direct current power supply, the LED is driven by using step-down constant current technology, which has the advantages of small power consumption and high efficiency, but real-time monitoring of LED driving current is required, and the circuit is complex and the cost is high.

[0004] In integrated circuits, LED driving circuits are often used to directly drive external LED lamps through bidirectional input and output ports, but the display brightness is easily affected by the power voltage. If the power voltage decreases, the driving current decreases, and the external LED lamp becomes dim; if the power voltage increases, the driving current increases, and the external LED lamp becomes bright.

[0005] In the prior art, the brightness of the LED lamp is easily affected by the power voltage. When the power voltage is low, the driving current decreases, and the external LED lamp becomes dim; when the power voltage is high, the driving current increases, and the external LED lamp becomes bright. In order to improve the display effect of the LED, the power port of the integrated circuit often adds an LDO to provide a stable power voltage; in order to improve the brightness of the LED lamp, a triode is often used to drive the LED lamp. These increase the overall cost and complexity of the system. SUMMARY

[0006] The present application overcomes the shortcomings of the prior art and provides an LED constant current driving circuit structure for realizing wide working voltage, which has the advantages of small power consumption, high efficiency and wide application range.

[0007] In order to achieve the above purpose, the LED constant current driving circuit structure for realizing wide working voltage comprises:

[0008] The LED constant current driving circuit structure for realizing wide working voltage mainly comprises:

[0009] Bandgap reference voltage circuit module, for generating bias voltage and zero-temperature coefficient reference voltage;

[0010] PTAT current generating circuit module, connected with the bandgap reference voltage circuit module, for generating output current through enable signal, reference voltage and bias voltage;

[0011] LED mirror current module, connected with the PTAT current generating circuit module, for generating multiple sets of bias currents through current mirror structure;

[0012] 8 LED constant current source circuit modules, each connected with the LED mirror current module, receiving bias current respectively to drive LED lamp.

[0013] Preferably, the PTAT current generating circuit module comprises a first operational amplifier, a first PMOS tube and a resistor, the first operational amplifier receives bias voltage and enable signal, the inverting input end receives reference voltage as reference voltage, the non-inverting input end is connected with the drain of the first PMOS tube, the output end is connected with the gate of the first PMOS tube, the drain of the first PMOS tube is also connected with the resistor, the other end of the resistor is grounded, and the source of the first PMOS tube is connected with external power supply voltage.

[0014] Preferably, the LED mirror current module comprises a second PMOS tube, a third PMOS tube, a fourth PMOS tube and a fifth PMOS tube, the drain of the second PMOS tube is connected with the source of the third PMOS tube, the source of the second PMOS tube is connected with external power supply voltage, the drain of the fourth PMOS tube is connected with the source of the fifth PMOS tube, and the source of the fourth PMOS tube is connected with external power supply voltage; the gates of the first PMOS tube, the third PMOS tube and the fifth PMOS tube are connected together, and the third PMOS tube, the fifth PMOS tube and the first PMOS tube constitute a current mirror.

[0015] Preferably, the LED mirror current module further comprises a first NMOS tube, a third NMOS tube, a fourth NMOS tube and a group of 16 pairs of NMOS tubes, the first NMOS tube, the third NMOS tube, the fourth NMOS tube and the group of 16 pairs of NMOS tubes constitute a high-swing common-source common-gate current mirror structure, the drain of the first NMOS tube is connected with the drain of the third PMOS tube, the source of the first NMOS tube is grounded, the gate of the first NMOS tube is connected with the drain, the drain of the third NMOS tube is connected with the drain of the fifth PMOS tube, the source of the third NMOS tube is connected with the drain of the fourth NMOS tube, the source of the fourth NMOS tube is grounded, and the gate of the fourth NMOS tube is connected with the drain of the third NMOS tube.

[0016] Each of the NMOS transistor groups comprises an upper NMOS transistor and a lower NMOS transistor, the source of the upper NMOS transistor is connected to the drain of the lower NMOS transistor, the gate of the upper NMOS transistor of each of the NMOS transistor groups is connected to the gate of the first NMOS transistor, the gate of the lower NMOS transistor of each of the NMOS transistor groups is connected to the gate of the fourth NMOS transistor, the source of the lower NMOS transistor is grounded, the drain of the upper NMOS transistor generates a bias current to form eight groups of bias currents and is output to the LED constant current source circuit module.

[0017] Preferably, the LED constant current source circuit module comprises a second operational amplifier, a sixth PMOS transistor, a seventh PMOS transistor, an eighth PMOS transistor, a ninth PMOS transistor, and a tenth NMOS transistor, the non-inverting input terminal of the second operational amplifier is connected to the drain of the seventh PMOS transistor, the inverting input terminal is connected to the drain of the eighth PMOS transistor, the output terminal is connected to the gate of the ninth PMOS transistor,

[0018] The gates of the sixth PMOS transistor, the seventh PMOS transistor, and the eighth PMOS transistor are connected together and connected to the drain of the sixth PMOS transistor, the source of the seventh PMOS transistor and the source of the eighth PMOS transistor are connected to a power supply voltage, the drain of the seventh PMOS transistor is connected to the source of the sixth PMOS transistor, the drain of the eighth PMOS transistor is connected to the source of the ninth PMOS transistor, the drain of the ninth PMOS transistor is connected to the drain of the tenth NMOS transistor, the source of the tenth NMOS transistor is grounded, and the drain of the sixth PMOS transistor is connected to a constant current IS2<0>.

[0019] Preferably, the eight LED constant current source circuit modules each have a constant current source output port, and the constant current source output port is connected to the drain of the ninth PMOS transistor.

[0020] Preferably, the LED constant current source circuit module further comprises a control terminal connected to the second operational amplifier and receiving a control signal ENH<0>, the control signal ENH<0> is obtained by ANDing an enable signal and an LED segment selection signal, in the case of a high level of ENH<0>, the constant current source output port outputs an LED constant current source, and the bias current IS1<0> of the LED mirror current module provides a bias current for the second operational amplifier.

[0021] Preferably, the LED constant current source circuit module further comprises a function selection terminal connected to the gate of the tenth NMOS transistor and receiving a signal ENL<0>, in the case of a low level of AIEN<0>, the constant current source output port is an analog channel and serves as an LED constant current driving port, and in the case of a high level of AIEN<0>, the constant current source output port is a digital channel and serves as a COM port for LED scanning.

[0022] Preferably, the constant current source output ports of the eight LED constant current source circuit modules are sequentially set as the common cathode COM ports of the LEDs, while the other seven constant current source output ports serve as driving ports for the LEDs.

[0023] Preferably, the width-to-length ratio of the first PMOS transistor, the third PMOS transistor, and the fifth PMOS transistor is 3:2:2.

[0024] The LED constant current drive circuit structure of this invention, which achieves a wide operating voltage range, can provide a constant LED drive current that is adjustable. This invention uses a 5V transistor design, enabling it to provide a constant LED drive current over a relatively wide operating voltage range. During operation, the external power supply does not require an LDO for voltage regulation. This LED constant current source drive circuit not only outputs the LED drive current but also serves as a common-cathode COM port during LED scanning, capable of withstanding sink currents exceeding 110mA. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the LED constant current drive circuit structure for achieving a wide operating voltage according to the present invention.

[0026] Figure 2 This is a schematic diagram of the PTAT current generation circuit module and the LED mirror current module for realizing the LED constant current drive circuit structure with a wide operating voltage according to the present invention.

[0027] Figure 3 This is a schematic diagram of an LED constant current source circuit module that realizes a wide operating voltage LED constant current drive circuit structure according to the present invention. Detailed Implementation

[0028] To more clearly describe the technical content of the present invention, the following description is provided in conjunction with specific embodiments.

[0029] This invention discloses an LED driving circuit that eliminates the need for an external transistor to drive the LED. It directly drives the LED through a bidirectional input / output port, reducing overall cost. Furthermore, it features a wide operating voltage range, and the LED driving current is unaffected by the external power supply voltage VDD, thus improving display performance. This invention offers advantages such as wide operating voltage, constant driving current, and low cost, while also providing good display quality.

[0030] like Figure 1 As shown, the LED constant current drive circuit structure of the present invention, which achieves a wide operating voltage, includes:

[0031] Bandgap reference voltage circuit module, used to generate Bias voltage and zero-temperature coefficient reference voltage ;

[0032] PTAT current generating circuit module, connected with the bandgap reference voltage circuit module, for generating output current through enable signal, reference voltage and bias voltage;

[0033] LED mirror current module LED IBIAS, connected with the PTAT current generating circuit module, for generating multiple sets of bias current through current mirror structure;

[0034] 8 LED constant current source circuit modules IO LED, each connected with the LED mirror current module, receiving bias current respectively, driving LED lamp.

[0035] Among them, at least 2 LED constant current source circuit modules IO LED can drive 2 LED lamps; in the embodiment of the application, 8 LED constant current source circuit modules IO LED are listed, which can drive up to 8*7 LED lamps.

[0036] The bandgap reference voltage circuit generates bias voltage VA and zero-temperature coefficient 1.2V reference voltage VBG, both of which are input to the PTAT module to generate PTAT current which is not affected by power supply voltage. Before enabling LEDEN, ENVB needs to be enabled first.

[0037] As shown in Figure 2 The PTAT current generating circuit module includes a first operational amplifier, a first PMOS tube and a resistor, the first operational amplifier receives bias voltage and enable signal, the inverting input end receives reference voltage as reference voltage, the non-inverting input end is connected with the drain of the first PMOS tube, the output end is connected with the gate of the first PMOS tube, the drain of the first PMOS tube is also connected with the resistor, the other end of the resistor is grounded, and the source of the first PMOS tube is connected with external power supply voltage.

[0038] In the PTAT current generating circuit, LEDEN is an enable signal, VA provides bias voltage for the operational amplifier, VBG is input to the inverting input end of the operational amplifier as reference voltage, the output voltage VBH of the operational amplifier is connected to the gate end of the first PMOS tube P0, the drain end VX of the first PMOS tube P0 is connected to the resistor R0 to ground, and VX is fed back to the non-inverting input end of the operational amplifier. According to the principle of "virtual short" and "virtual open" of the operational amplifier, VX=VBG, therefore, the current flowing through the first PMOS tube P0 and the resistor R0 is a constant value, which is not affected by power supply voltage, IPTAT=VBG / R0, about 12uA.

[0039] As shown in Figure 2As shown, the LED mirror current module comprises a second PMOS tube, a third PMOS tube, a fourth PMOS tube and a fifth PMOS tube, the drain of the second PMOS tube is connected with the source of the third PMOS tube, the source of the second PMOS tube is connected with an external power supply voltage, the drain of the fourth PMOS tube is connected with the source of the fifth PMOS tube, and the source of the fourth PMOS tube is connected with the external power supply voltage; the gates of the first PMOS tube, the third PMOS tube and the fifth PMOS tube are connected together, and the third PMOS tube, the fifth PMOS tube and the first PMOS tube constitute a current mirror.

[0040] As a preferred embodiment of the present application, the LED mirror current module further comprises a first NMOS tube, a third NMOS tube, a fourth NMOS tube and 16 pairs of NMOS tube groups, the first NMOS tube, the third NMOS tube, the fourth NMOS tube and the 16 pairs of NMOS tube groups constitute a high-swing common-source common-gate current mirror structure, the drain of the first NMOS tube is connected with the drain of the third PMOS tube, the source of the first NMOS tube is grounded, the gate of the first NMOS tube is connected with the drain, the drain of the third NMOS tube is connected with the drain of the fifth PMOS tube, the source of the third NMOS tube is connected with the drain of the fourth NMOS tube, the source of the fourth NMOS tube is grounded, and the gate of the fourth NMOS tube is connected with the drain of the third NMOS tube.

[0041] Each of the NMOS tube groups comprises an upper NMOS tube and a lower NMOS tube, the source of the upper NMOS tube is connected with the drain of the lower NMOS tube, the gate of the upper NMOS tube of each of the NMOS tube groups is connected with the gate of the first NMOS tube, the gate of the lower NMOS tube of each of the NMOS tube groups is connected with the gate of the fourth NMOS tube, the source of the lower NMOS tube is grounded, and the drain of the upper NMOS tube generates a bias current to constitute 8 groups of bias currents and output to an LED constant current source circuit module.

[0042] In the LED mirror current module LED IBIAS, the third PMOS tube P2, the fifth PMOS tube P4 and the first PMOS tube P0 in the PTAT constitute a current mirror, the width-length ratios of the first PMOS tube P0, the third PMOS tube P2 and the fifth PMOS tube P4 are 3:2:2, therefore, the currents IT1 and IT2 are about 8uA. At the same time, the first NMOS tube N0, the third NMOS tube N2 and the fourth NMOS tube N3, N17 and N27, …, N10 and N20, N37 and N47, …, N30 and N40 in the LED mirror current module constitute a high-swing common-source common-gate current mirror structure, the structure not only has high output impedance, large output swing and small influence of power voltage, but also can relatively accurately achieve a current ratio of 1:1, using two currents IT1 and IT2, 8 groups of bias currents IS1 = IT1, IS2 = 5 x IT1, i = 0, 1,..., 6, 7, respectively. Thus, IS1 about 8 uA, IS2 About 40uA. The 8 groups of bias current are respectively delivered to PT1<0>, PT1<1>, … PT1<7> the 8 LED constant current source output ports.

[0043] The 8 groups of mirror current IS1<0> and IS2<0>, IS1<1> and IS2<1>, IS1<2> and IS2<2>, IS1<3> and IS2<3>, IS1<4> and IS2<4>, IS1<5> and IS2<5>, IS1<6> and IS2<6>, IS1<7> and IS2<7> generated by the LED mirror current module are respectively connected to the 8 LED constant current source circuits IO_LED, and the 8 LED constant current source circuits IO_LED are respectively connected to the external bidirectional input ports PT1<0>, PT1<1>, … PT1<7>.

[0044] As shown in Figure 3 The LED constant current source circuit module includes a second operational amplifier, a sixth PMOS tube, a seventh PMOS tube, an eighth PMOS tube, a ninth PMOS tube, and a tenth NMOS tube. The non-inverting input terminal of the second operational amplifier is connected to the drain of the seventh PMOS tube, the inverting input terminal is connected to the drain of the eighth PMOS tube, and the output terminal is connected to the gate of the ninth PMOS tube.

[0045] The gates of the sixth PMOS tube, the seventh PMOS tube, and the eighth PMOS tube are connected together and connected to the drain of the sixth PMOS tube. The source of the seventh PMOS tube and the source of the eighth PMOS tube are connected to the power supply voltage. The drain of the seventh PMOS tube is connected to the source of the sixth PMOS tube. The drain of the eighth PMOS tube is connected to the source of the ninth PMOS tube. The drain of the ninth PMOS tube is connected to the drain of the tenth NMOS tube. The source of the tenth NMOS tube is connected to the ground. The drain of the sixth PMOS tube is connected to the constant current IS2<0>.

[0046] The connected port of the LED constant current source circuit IO_LED is PT1<0>. IS1<0> provides a stable bias current for the second operational amplifier I1, and IS2<0> is an input constant current source for mirror generation of a larger output constant current source.

[0047] The LED constant current driving circuit is composed of the second operational amplifier I1 and PMOS tubes P5-P8. LEDEN is an enable signal of the LED module, and LEDSEG<0> is an LED segment selection signal of PT1<0>. LEDEN and LEDSEG<0> are ANDed to obtain ENH<0>. When ENH<0> is at a high level, the LED constant current source of PT1<0> is allowed to output, so as to light the external LED lamp. According to the "virtual short" and "virtual open" principles of the operational amplifier, the voltages at the two input terminals of the second operational amplifier I1 are equal, i.e. VN=VP, so that the three-terminal voltages of the seventh PMOS tube P6 and the eighth PMOS tube P7 are equal, and the current can be accurately mirrored according to 1:m, so as to achieve the purpose of constant current output. LEDCUR0<1:0> is a current selection signal of the PT1<0> constant current driving circuit, and m is minimum 200 and maximum 400, i.e. the output constant current source of PT1<0> is minimum 8 mA and maximum 16 mA.

[0048] AIEN<0> is a function selection signal of the PT1<0> port, and IO_BGDRV is a COM port large current driving enable during LED scanning. When AIEN<0> is at a low level, PT1<0> is configured as an analog channel, the input, output and pull-up functions of the bidirectional input and output port are disabled, and PT1<0> is only used as an LED constant current driving port. When AIEN<0> is at a high level, PT1<0> is configured as a digital channel. At this time, if PT1<0> is set to output a low level, CN<0> will be at a high level. When IO_BGDRV is at a high level, ENL<0> is at a high level, and PT1<0> will output a low level with strong driving ability, which can withstand a pouring current of more than 110 mA, and is used as the COM port during LED scanning.

[0049] The eight LED driving ports PT1<0>, PT1<1>, …, PT1<7> can be sequentially set as a common negative COM port of the LED, and the other seven ports are used as LED end driving ports. At this moment, seven external LED lamps can be driven at the same time. In the whole scanning period, 56 LED lamps can be driven at most.

[0050] ENVB, LEDEN, AIEN<7:0>, IO_BGDRV, LEDCUR0<1:0>, LEDCUR1<1:0>, … LEDCUR7<1:0>, LEDSEG<7:0> are from the digital control circuit. ENVB enables the bandgap reference voltage circuit; LEDEN enables the whole LED constant current driving circuit; AIEN<7:0> sets each LED constant current driving port as a constant current output or a current input COM port; when the LED constant current driving port is as a current input COM port, IO_BGDRV can enable its large current driving; LEDCUR0<1:0>, LEDCUR1<1:0>, … LEDCUR7<1:0> are the output current sizes of each LED constant current driving port; LEDSEG<7:0> determines whether each LED constant current module outputs a constant current source.

[0051] As a preferred embodiment of the application, the eight LED constant current source circuit modules each have a constant current source output port connected at the drain of the ninth PMOS tube.

[0052] As a preferred embodiment of the application, the LED constant current source circuit module further comprises a control terminal connected with the second operational amplifier and receiving a control signal ENH<0>, which is obtained by the AND operation of an enable signal and an LED segment selection signal; in the case of high level of ENH<0>, the constant current source output port outputs an LED constant current source, and the bias current IS1<0> of the LED mirror current module provides a bias current for the second operational amplifier.

[0053] As a preferred embodiment of the application, the LED constant current source circuit module further comprises a function selection terminal connected with the gate of the tenth NMOS tube and receiving a signal ENL<0>; in the case of low level of AIEN<0>, the constant current source output port is an analog channel and is as an LED constant current driving port; in the case of high level of AIEN<0>, the constant current source output port is a digital channel and is as a COM port of LED scanning.

[0054] As a preferred embodiment of the application, the constant current source output ports of the eight LED constant current source circuit modules are sequentially set as the common cathode COM ports of LEDs, and the remaining seven constant current source output ports are as driving ports of LEDs.

[0055] As a preferred embodiment of the application, the width-length ratios of the first PMOS tube, the third PMOS tube and the fifth PMOS tube are 3:2:2.

[0056] The circuit structure is simple, two bidirectional input and output ports can only drive one LED lamp at the same time, if time scanning, n constant current driving ports, can drive n x (n-1) LED lamps at most, suitable for small LED display screen composed of LED lamp, such as human body scale, kitchen scale display screen. The constant current sources of the circuit structure are all mirrored from the same mirror current module LED_IBIAS, the current error between the constant current sources is small.

[0057] The working voltage range of the circuit structure is wide, suitable for working occasions of double battery and three battery. The output current of the circuit structure is constant, the brightness of single LED lamp or multiple LED lamps is the same at the same time, the display effect is good. The output current of the circuit structure can be adjusted. The external power supply does not need to be connected with LDO voltage stabilizing, and does not need to be connected with a transistor to provide large driving current, the cost is relatively low.

[0058] The LED constant current driving circuit structure for realizing wide working voltage of the application can provide constant LED driving current, and the current can be adjusted. The application adopts 5V tube design, can provide constant LED driving current in a wide working voltage range. The external power supply does not need to be connected with LDO for voltage stabilizing when the application works. The LED constant current source driving circuit of the application can not only output LED driving current, but also can be used as COM port when scanning LED, and can bear 110mA or more filling current.

[0059] In this specification, the application has been described with reference to its specific embodiments. However, it is obvious that various modifications and changes can be made without departing from the spirit and scope of the application. Therefore, the specification and drawings should be considered as illustrative rather than limiting.

Claims

1. A LED constant current driving circuit structure for realizing wide working voltage, characterized in that, The circuit structure comprises: a bandgap reference voltage circuit module for generating a bias voltage and a zero-temperature coefficient reference voltage; a PTAT current generation circuit module connected with the bandgap reference voltage circuit module, for generating an output current through an external enable signal LEDEN, the reference voltage and the bias voltage; an LED mirror current module connected with the PTAT current generation circuit module, for generating a plurality of bias currents; a plurality of LED constant current source circuit modules connected with the LED mirror current module respectively, for receiving the bias currents respectively, so as to drive LED lamps, wherein the LED constant current source circuit module comprises a second operational amplifier, a sixth PMOS tube, a seventh PMOS tube, an eighth PMOS tube, a ninth PMOS tube and a tenth NMOS tube, the non-inverting input terminal of the second operational amplifier is connected with the drain of the seventh PMOS tube, the inverting input terminal is connected with the drain of the eighth PMOS tube, and the output terminal is connected with the gate of the ninth PMOS tube; the gates of the sixth PMOS tube, the seventh PMOS tube and the eighth PMOS tube are connected to one point, and the drain of the sixth PMOS tube is connected with the gates, the source of the seventh PMOS tube and the source of the eighth PMOS tube are connected with an external power supply voltage, the drain of the seventh PMOS tube is connected with the source of the sixth PMOS tube, the drain of the eighth PMOS tube is connected with the source of the ninth PMOS tube, the drain of the ninth PMOS tube is connected with the drain of the tenth NMOS tube, the source of the tenth NMOS tube is connected with the ground, and the drain of the sixth PMOS tube is connected with one of the plurality of bias currents generated by the LED mirror current module; the PTAT current generation circuit module comprises a first operational amplifier, a first PMOS tube and a resistor, the first operational amplifier receives the bias voltage and the enable signal, the inverting input terminal receives the reference voltage as a reference voltage, the non-inverting input terminal is connected with the drain of the first PMOS tube, the output terminal is connected with the gate of the first PMOS tube, the drain of the first PMOS tube is further connected with the resistor, the other end of the resistor is connected with the ground, and the source of the first PMOS tube is connected with an external power supply voltage; the LED mirror current module comprises a second PMOS tube, a third PMOS tube, a fourth PMOS tube and a fifth PMOS tube, the drain of the second PMOS tube is connected with the source of the third PMOS tube, the source of the second PMOS tube is connected with the external power supply voltage, the drain of the fourth PMOS tube is connected with the source of the fifth PMOS tube, the source of the fourth PMOS tube is connected with the external power supply voltage, the gates of the first PMOS tube, the third PMOS tube and the fifth PMOS tube are connected in sequence, and the third PMOS tube, the fifth PMOS tube and the first PMOS tube form a current mirror structure. The LED mirror current module further comprises a first NMOS tube, a third NMOS tube, a fourth NMOS tube and a plurality of NMOS tube groups, the first NMOS tube, the third NMOS tube, the fourth NMOS tube and the 16 pairs of NMOS tube groups constitute a high swing common source common gate current mirror structure, the drain of the first NMOS tube is connected with the drain of the third PMOS tube, the source of the first NMOS tube is grounded, the gate of the first NMOS tube is connected with the drain of the first NMOS tube, the drain of the third NMOS tube is connected with the drain of the fifth PMOS tube, the source of the third NMOS tube is connected with the drain of the fourth NMOS tube, the source of the fourth NMOS tube is grounded, and the gate of the fourth NMOS tube is connected with the drain of the third NMOS tube. Each of the NMOS tube groups comprises an upper NMOS tube and a lower NMOS tube, the source of the upper NMOS tube is connected with the drain of the lower NMOS tube, the gate of the upper NMOS tube of each NMOS tube group is connected with the gate of the first NMOS tube, the gate of the lower NMOS tube of each NMOS tube group is connected with the gate of the fourth NMOS tube, the source of the lower NMOS tube of each NMOS tube group is grounded, the drain of the upper NMOS tube of each NMOS tube group generates a bias current, and the bias current generated by each NMOS tube group is output to a corresponding LED constant current source circuit module.

2. The LED constant current driving circuit structure achieving wide working voltage according to claim 1, characterized in that, The plurality of LED constant current source circuit modules each have a constant current source output port, and the constant current source output port is connected with the drain of the ninth PMOS tube.

3. The LED constant current driving circuit structure achieving wide working voltage according to claim 2, characterized in that, The LED constant current source circuit module further comprises a control end connected with the second operational amplifier and receiving an LED current output enable signal ENH<0>, the LED current output enable signal ENH<0> is obtained by performing an AND operation on an external enable signal LEDEN and an LED segment selection signal LEDSEG<0>, in a case where the LED current output enable signal ENH<0> is at a high level, the constant current source output port outputs an LED constant current source, and the LED mirror current module is used to provide a bias current for the second operational amplifier.

4. The LED constant current driving circuit structure achieving wide working voltage according to claim 2, characterized in that, The LED constant current source circuit module further comprises a function selection end connected with the gate of the tenth NMOS tube and receiving an LED current input enable signal ENL<0>, in a case where a function selection signal AIEN<0> is at a low level, the constant current source output port is an analog channel and serves as an LED constant current driving port, and in a case where the function selection signal AIEN<0> is at a high level, the constant current source output port is a digital channel and serves as a COM port of LED scanning.

5. The LED constant current driving circuit structure achieving wide working voltage according to claim 2, characterized in that, The constant current source output ports of the plurality of LED constant current source circuit modules are sequentially arranged, one of which is set as a common cathode COM port of the LED, and the others are set as LED constant current source output ports.

6. The LED constant current driving circuit structure achieving wide working voltage according to claim 1, characterized in that, The width-length ratio of the first PMOS tube, the third PMOS tube and the fifth PMOS tube is 3:2:2.

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