TWI713409B - A led driving circuit - Google Patents

Abstract

A LED driving circuit, which provides constant driving current based on the embedded semiconductor resistance, the non-volatile memory (NVM), the external calibration signal, and the external current magnification signal. The external calibration signal is stored in the non-volatile memory. All input signals could be input through the same pin. Such that the driving circuit does not need an external resistor and does not has to occupy an extra pin of the integrated circuit package. The PCB routing will become easier; the required PCB area is smaller. The cost of the external resistor and soldering and mounting is also saved.

Description

Driving circuit for LED

The present invention relates to the technical field of circuits, in particular to a driving circuit for LEDs.

With the continuous development of science and technology, light emitting diodes (LED, Light Emitting Diode) have been more and more widely used in daily life. For the purpose of safety, reliability, and accuracy, LED products need a drive circuit to output a constant current. At present, the LED driving circuit usually uses an external resistor outside the chip to set the output current. However, this method of providing a constant drive current requires an additional pin of the chip to connect to an external resistor, which will increase the cost and occupy the circuit substrate (the common substrate is a printed circuit board (PCB, Printed Circuit Board)) Area, which not only increases the design difficulty for developers, leads to an increase in PCB area and winding difficulty, but also increases the processing cost of the drive circuit.

The technical problem to be solved by the present invention is to provide an LED drive circuit, which uses a semiconductor process to manufacture internal resistance, which can be integrated with the drive circuit in the same chip, so as to solve the increase in design difficulty caused by the use of external circuits. The number of pins increases, PCB area increases, winding difficulty increases, and processing costs increase.

In order to achieve the above purpose of the invention, the present invention uses the following technical solutions.

According to one aspect of the present invention, there is provided a driving circuit for LED, the driving circuit includes a non-volatile memory (NVM, Non-Volatile Memory) and a constant current module, the constant current module is provided with a semiconductor resistor inside . The non-volatile memory is used to store the externally input calibration control signal to ensure that the output current can be calibrated to the target value according to the calibration control signal stored in the non-volatile memory after each power-on The correction control signal is repeatedly input after power-on; the constant current module generates a constant drive current based on the semiconductor resistance, the correction control signal, and the current multiplier signal provided by the outside.

Optionally, the constant current module specifically includes: a voltage generating module for providing a reference voltage; a current generating module including the semiconductor resistor, wherein the semiconductor resistor is an adjustable semiconductor resistor; The current generating module is used for adjusting the semiconductor resistance according to the correction control signal, and generating a constant driving current according to the reference voltage, the adjusted semiconductor resistance value, and a current multiplier signal provided by the outside.

Optionally, the constant current module specifically includes: a voltage generating module for providing a reference voltage; a current generating module, including the semiconductor resistor and a current mirror circuit, according to the calibration control stored in the non-volatile memory The signal correctively fine-tunes the current mirror to obtain the reference current according to the reference voltage and semiconductor resistance, and adjusts the current mirror magnification according to the current magnification signal provided by the outside to generate a constant drive current.

Optionally, the current generation module includes a correction unit and a magnification adjustment unit; wherein, the correction unit includes an adjustable semiconductor resistor for adjusting the resistance of the semiconductor resistor according to a correction control signal stored in a non-volatile memory. The magnification adjustment unit includes a current mirror circuit for obtaining a reference current according to the reference voltage and the adjusted resistance value of the semiconductor resistor, and adjusting the magnification of the reference current according to a current magnification signal provided by the outside , To produce a constant drive current.

Optionally, the constant current module includes: a voltage generating module, including the semiconductor resistor, wherein the semiconductor resistor is an adjustable semiconductor resistor, and the voltage generating module is used for storing in a nonvolatile The correction control signal of the memory adjusts the semiconductor resistor to obtain the required reference voltage; the current generation module includes a current mirror circuit, which is used to obtain the reference current according to the reference voltage and the current magnification signal provided by the outside. The reference current is adjusted for magnification to generate a constant drive current.

Optionally, the current mirror circuit is formed by a first-level current mirror or more than one-level current mirrors connected in series; the input side of the current mirror circuit is used to obtain the reference current, and the input side and/or output side is based on the current The magnification signal controls the conduction number of the transistors at all levels (the commonly used transistor is a metal-oxide field-effect transistor (MOSFET, Metal-Oxide-Semiconductor Field-Effect Transistor, referred to as MOS)) to adjust the output constant drive current relative to The ratio of the reference current.

Optionally, the semiconductor resistor includes a plurality of transistors and a plurality of resistors; the plurality of transistors are used to turn on and off according to a correction control signal to control the number of conductions of the resistors in the semiconductor resistor.

Optionally, the semiconductor resistor adopts a material with a low temperature coefficient, or is composed of two or more materials with opposite temperature coefficients.

Optionally, the constant current module specifically includes: a voltage generating module including the semiconductor resistor, wherein the semiconductor resistor is an adjustable semiconductor resistor, and the voltage generating module is used to generate a current The magnification signal is used to adjust the magnification of the semiconductor resistor to obtain the required reference voltage; the current generation module, including a current mirror circuit, is used to adjust the reference voltage and the correction control signal stored in the non-volatile memory The current mirror is adjusted to generate a constant drive current.

Optionally, the constant current module includes: a voltage generating module, including the semiconductor resistor, wherein the semiconductor resistor is an adjustable semiconductor resistor, and the voltage generating module is used for storing in a nonvolatile The correction control signal of the memory adjusts the semiconductor resistor, and adjusts the magnification of another semiconductor resistor according to the current magnification signal provided by the outside, so as to obtain the required reference voltage; the current generation module includes a current mirror circuit, Used to obtain the reference current according to the reference voltage to generate a constant drive current.

Optionally, further, the present invention inputs the externally input calibration control signal and the current multiplier signal from the same signal input terminal in a time-sharing manner, and connects to a shift register (Shift-in Register) for receiving It also temporarily stores various externally input signals. The shift register outputs the correction control signal to the aforementioned non-volatile memory, and sends the current rate signal to the aforementioned corresponding control circuit, so that the chip footprint can be simplified Realize the control of the drive circuit.

Optionally, and further, the correction control signal or current multiplier signal signal output by the aforementioned shift register can be stored in a configuration register (Configuration Register), and then the configuration register It is transmitted to the aforementioned non-volatile memory or drive circuit, which can reduce the repeated input of the same signal and simplify the control procedure.

The LED drive circuit provided by the present invention adopts the form of setting an internal resistance. The internal resistance is a resistance in the semiconductor manufacturing process. The resistance value is corrected according to the correction control signal stored in the non-volatile memory, or the current mirror magnification is fine-tuned, To compensate for the error of the semiconductor resistance, it is equivalent to correcting the resistance; and then the output current is adjusted according to the external current ratio signal, so that the entire driving circuit can accurately output the required constant driving current. The above resistors are selected from low temperature coefficient semiconductor resistors, which can output a constant drive current. And only use the same signal input terminal, time-sharing input correction control signal, and current multiplier signal. Therefore, the present invention does not need to occupy additional chip pins, which improves the utilization rate of chip pins. At the same time, it can save the cost of external resistance, effectively reduce the PCB area, reduce the winding difficulty and the processing cost of the entire driving circuit.

10: LED drive circuit

110: Constant current module

120: Non-volatile memory

130: shift register

140: Configuration register

150: signal input

160: drive current output

1110: Current generation module

1120: Voltage generation module

1130: Semiconductor resistance

11110: correction unit

11120: Magnification adjustment unit

BG: Bandgap reference voltage circuit

CGA<2:0>: Current rate signal

CGB<2:0>: Current rate signal

CGC<2:0>: Current rate signal

CGD<2:0>: Current rate signal

CGE<2:0>: Current rate signal

IOUT, IOUT2~4: constant drive current

M1~M33: switching transistor

MN1~MN6: NMOS, constitute an adjustable current mirror

MN10, MN11: NMOS

MP1~MP10: PMOS, constitute an adjustable current mirror

OP1, OP2, OP4: operational amplifier

R1~R5: Semiconductor adjustable resistance

R6, R7: Semiconductor resistance

Trim1~Trim4: Correction control signal

VBG: Bandgap reference voltage

VREF2: Reference voltage

Fig. 1 is a schematic diagram of a principle structure of an LED drive circuit in an embodiment of the present invention; Fig. 2 is a principle structure diagram of an LED drive circuit in an alternative embodiment of the present invention; Fig. 3 is an alternative embodiment of the present invention Fig. 4 is a schematic structure diagram of an LED drive circuit in an optional embodiment of the present invention; Fig. 5 is a schematic structure diagram of a correction unit in an optional embodiment of the present invention; 6 is a circuit diagram of a driving circuit in an alternative specific embodiment of the present invention; FIG. 7 is a circuit diagram of a driving circuit in an alternative specific embodiment of the present invention; FIG. 8 is a circuit diagram of a driving circuit in an alternative specific embodiment of the present invention; Fig. 9 is a circuit diagram of a driving circuit in an alternative embodiment of the present invention; Fig. 10 is a circuit diagram of a driving circuit in an alternative embodiment of the present invention; Fig. 11 is a circuit diagram for an LED driving circuit in an alternative embodiment of the present invention Figure 12 is a schematic structural diagram of an LED drive circuit in an alternative embodiment of the present invention; Figure 13 is a schematic structural diagram of an LED drive circuit in an alternative embodiment of the present invention; Figure 14 is A schematic structure diagram of an LED driving circuit in an optional embodiment of the present invention; FIG. 15 is a schematic structure diagram of an LED driving circuit in an optional embodiment of the present invention;

The following describes the technical means adopted by the present invention to achieve the intended purpose of the invention in conjunction with the drawings and preferred embodiments of the present invention.

The present invention provides a LED driving circuit 10 as shown in FIG. 1. The driving circuit includes a signal input terminal 150 for time-sharing input of externally input correction control signals and current magnification signals; and a driving current output terminal 160; And a constant current module 110; and a non-volatile memory 120; the constant current module is provided with a semiconductor resistor 1130; the non-volatile memory stores the calibration control signal provided by the outside, and the driving circuit is based on the non-volatile memory The calibration control signal stored in the body, the current rate signal provided by the outside, and the internal semiconductor resistor generate a constant drive current. Among them, the drive circuit adjusts the semiconductor adjustable resistance according to the correction control signal, or fine-tunes the current mirror magnification to compensate for the error of the semiconductor resistance, which is equivalent to correcting the resistance to correct the final output constant drive current. How to adjust and The correction will be described in detail later.

The above-mentioned semiconductor resistors are internal resistors, which are made by semiconductor technology and can be composed of one or more resistors of different materials, and have the characteristics of low temperature coefficient (the resistance value changes with a small change in temperature). Specifically, semiconductor resistors It uses a low temperature coefficient material, or is composed of two or more materials with opposite temperature coefficients. However, the resistance of internal resistors manufactured by semiconductor technology varies greatly, including resistance errors between chips, and resistance differences at different temperatures, which generally cannot be used as a basis for accurate current output; and the internal resistance itself is not easy to replace, nor can it be like an external resistance. The output current can also be set flexibly. Therefore, in the present invention, the resistance value or current mirror magnification is corrected by the correction control signal, and the current is adjusted according to the current magnification signal, so that the entire driving circuit can accurately output the required constant driving current.

In an embodiment of the present invention, as shown in FIG. 2, the constant current module used in the LED driving circuit specifically includes: a voltage generating module 1120 for providing a reference voltage; the voltage generating module in the present invention can be used Bandgap reference voltage circuit implementation, which is a technique well known to those skilled in the art, and will not be introduced here too much.

The current generating module 1110 includes the semiconductor resistor, and the semiconductor resistor is designed to have an adjustable resistance value, and is used to adjust the resistance value of the semiconductor resistor according to the correction control signal stored in the non-volatile memory Make adjustments and generate a constant drive current based on the reference voltage, the adjusted resistance value and the current multiplier signal provided by the outside.

Another implementation of the current generation module includes a semiconductor resistor and a current mirror circuit. The current mirror circuit is corrected and fine-tuned according to the correction control signal stored in the non-volatile memory to compensate for the error of the semiconductor resistance. The resistance is equivalent, and the reference current is obtained according to the reference voltage and the semiconductor resistance; and the current mirror magnification is adjusted according to the current magnification signal provided by the outside, so as to multiply the reference current to generate a constant drive current.

The above-mentioned semiconductor resistors can be combined with resistors of one or more materials to generate low temperature coefficient resistors and thereby generate a constant driving current.

The above-mentioned correction control signal and current rate signal can be provided by an external device, for example, a controller can output different control signals through control commands. The LED drive circuit used in the present invention can achieve constant drive current output by adopting internal resistance without occupying additional chip pins, which improves the utilization rate of chip pins. At the same time, it can effectively reduce PCB area and reduce winding. Difficulty and processing cost of the entire drive circuit.

In an embodiment of the present invention, as shown in FIG. 3, the constant current module used for the LED driving circuit specifically includes: a voltage generating module for providing a reference voltage; including an adjustable semiconductor resistor, which is stored in a non-volatile The calibration control signal of the flexible memory adjusts the semiconductor resistance to adjust the required reference voltage; the current generation module is used to generate a constant driving current according to the adjusted reference voltage and the current multiplier signal provided by the outside.

In a specific embodiment of FIG. 2 of the present invention, the current generation module includes a correction unit 11110 and a magnification adjustment unit 11120. As shown in Figure 4, the correction unit includes an adjustable semiconductor resistor, which is adjusted according to the correction control signal stored in the non-volatile memory; the magnification adjustment unit includes a current mirror circuit, and the semiconductor resistor is adjusted according to the reference voltage. The resistance value of the resistor obtains the reference current and the externally provided current rate signal performs rate adjustment on the reference current to generate a constant drive current; wherein, for the realization of the adjustable semiconductor resistor, in an embodiment of the present invention, multiple transistors are used (Because MOS is most often used, hereinafter referred to as MOS) and a semiconductor resistor composed of multiple resistors. A plurality of MOSs are turned on and off according to the correction control signal to control the number of conduction of the resistance in the semiconductor resistor. For example, as shown in FIG. 5, multiple MOSs are turned on and off according to the correction control signals trim1, trim2... trim4 to control the number of conductions of the resistors R1 to R5 in the semiconductor adjustable resistor. Need to explain Yes, in this figure, the number of resistors and MOS can be adjusted according to actual needs to select a suitable resistor adjustment range. Of course, other forms of realizing resistance correction by correcting the control signal can be adopted, and the implementation manner provided in the present invention is only for illustration and not for limiting the technical content of the present invention. For the above-mentioned several embodiments, the current mirror circuit may be formed by using one-stage current mirror or current mirrors of more than one stage connected in series. The input side of the current mirror circuit is used to obtain the reference current, and the input side and/or the output side control the conduction number of the MOS of each stage according to the current magnification signal to adjust the magnification of the output constant drive current relative to the reference current .

Here, it is mentioned that there are multiple implementation forms for the reference current magnification according to the current magnification signal. The current can be adjusted on the input side and/or the output side, including: One way is that the input side of the current mirror circuit can be connected to the reference The voltage generates a reference current, and the input side and the output side simultaneously adjust the reference current according to the current ratio signal to obtain a constant drive current that meets the set size. Specifically, when the reference voltage is connected to the input side, the input side of the current mirror circuit directly obtains the reference current according to the reference voltage and the conduction resistance; the input side and the output side control the conduction number of the MOS according to the current magnification signal, and adjust the magnification of the current mirror , Get the current that meets the set size.

In an alternative specific embodiment, as shown in FIG. 6, the bandgap reference voltage circuit BG outputs the bandgap reference voltage VBG, the input side of the current mirror circuit includes MOS MP1, MP2, and MP3, and the negative phase input terminal of the operational amplifier OP1 is connected VBG, the positive phase input terminal is connected to semiconductor resistors R1~R5, and the output terminal is connected to the gate of the current mirror PMOS MP1~MP6 through the switch MOS M4, M5, M6, M10, M11, M12, forming a negative feedback loop. When the operational amplifier OP1 is used to stabilize the negative feedback circuit, the voltage at its two input terminals will be close. It can be connected to the reference voltage VBG and the on-resistance R1~R5 of the adjustable semiconductor resistor to generate a reference current; The side includes MOS MP4, MP5, MP6. Components M1~M12 are switching components, which can be turned on or off according to the signal current ratio signals CGA<2:0>, CGB<2:0> to control MP1~MP6 to turn on or off. For the components M1~M12, multiple selectors and other components that realize the switch control function can be selected, which can also be integrated in the same component device, and there is no specific limitation here. By controlling the MOS MP1~MP6 to turn on or off, the current magnification between the output side and the input side can be controlled. The total output mirror current is the reference current after the magnification, which is the constant drive current IOUT in the present invention. Here, on the input side and the output side according to the current magnification signal to control the number of MOS conduction can achieve the reference current magnification adjustment. Therefore, when selecting the required current magnification, you can also increase or decrease the parallel current mirror MOS on the input side or the output side. The length and width of the input side and output side MOS are not specifically limited, and can be selected according to the actual current required.

The above-mentioned method of generating a constant reference current using the structure of an operational amplifier and a reference voltage, a current mirror, and a resistor is only a simple embodiment in practical applications. There are also many equivalent circuits that can achieve the effect of generating a constant drive current based on the same principle. For example, the current magnification signal can also only be used to adjust the magnification of the output side, and for example, an adjustable semiconductor resistor can be selected to implement the current magnification adjustment function. The present invention includes but is not limited to this embodiment.

The above-mentioned current mirror can also be used to correct the current at the same time. If the above-mentioned semiconductor resistance value is not directly corrected, a correction control circuit can be added to one of the current mirror stages to control the conduction amount of the current mirror MOS to correct the final output current. , To achieve the same effect as the correction resistor. For example, you can choose to correct the current on the input side in Figure 6 above. The semiconductor resistors can be in the form shown in the figure, namely resistors R1~R5, or fixed-value semiconductor resistors can be used to correct the reference current according to the correction control signal to achieve Same effect as correcting semiconductor resistance. Specifically, according to the correction control signal CGA<2:0>, by controlling M1~M6 to be turned on or off, MP1~MP3 can be controlled to be turned on or off, and the output reference current can be corrected. Generally, the amplitude of the corrected current change is much smaller than that of the aforementioned current magnification, so the MOS width/length ratio (Width/Length) used for correction is usually small to achieve the purpose of fine-tuning the current. In this way, the signal on the input side is used to calibrate the reference current, and then the output side adjusts the magnification according to the current magnification signal CGB<2:0>.

Among them, the current mirror can adopt a parallel structure to realize the output of one or more constant drive currents. For example, the output side in Figure 6 is copied and connected in parallel, that is, MP7~MP9 and M17~M22 in Figure 7, which can generate the first Two current outputs IOUT2. In this way, multiple constant drive currents can be output through parallel connection.

For the specific realization of the current mirror circuit, a PMOS current mirror or an NMOS current mirror can be used according to the application requirements, or more than one set of PMOS current mirrors and more than one set of NMOS current mirrors are connected in series, as shown in Figure 8. The current magnification adjustment function can be implemented in one or more of the current mirrors according to the actual application. As shown in Figure 8, the output and input sides of the two-stage current mirror in series have the current magnification adjustment function. In the present invention, the form of the current mirror and the current magnification adjustment form are not specifically limited.

At the same time, in order to reduce the output current change of the current mirror under different output voltages, a Cascode current mirror can be selected. The overlapping current mirror belongs to a technique well known to those skilled in the art, and will not be repeated here.

In an alternative specific embodiment, as shown in Figure 9, the output of the voltage generating module is connected to the positive input terminal of the operational amplifier OP1, the negative input terminal is connected to the adjustable semiconductor resistors R1~R5, and the output terminal is connected to the gate of the NMOS , Constitute a negative feedback loop. The drain of the NMOS is connected to the current mirror of the PMOS, and the source (Source) Connect the adjustable semiconductor resistor to the negative input terminal of OP1. At the output end of the PMOS current mirror, op amp OP2 and PMOS MP10 are used instead. The positive and negative ends of the op amp OP2 are connected to the drains of PMOS MP1~MP3 and PMOS MP4~MP6 respectively, so as to ensure the VGS (gate-source voltage) and VDS (drain-source voltage) of the PMOS on the input and output sides The voltage of the pole voltage) is the same, so that the current mirror outputs a constant drive current proportional to the reference current.

The PMOS current mirror method of FIG. 9 can also be used for NMOS, and is connected in series with the PMOS current mirror of FIG. 9 to output a constant drive current.

In addition, one of the alternative specific embodiments of FIG. 3 can be seen in FIG. 10. In this drive circuit, the bandgap reference circuit BG generates VBG, which is connected to the positive phase input end of the operational amplifier OP4 in Figure 10, the negative phase input end is connected to the adjustable semiconductor resistors R1~R5, and the output end is connected to the gate of the NMOS. The drain of the NMOS is connected to the voltage VDD, and the source is connected to the negative input of the adjustable semiconductor resistors R1~R5 and OP4. The semiconductor resistors R1 to R5 are connected to the voltage VSS through the resistor R6, and the semiconductor resistors R1 to R5 are connected to the resistor R6. Where is the output terminal of the reference voltage VREF2. The conduction number of the adjustable semiconductor resistors R1 to R5 is controlled by the correction control signal, so that the reference voltage outputs different values. The reference voltage VREF2 is subsequently connected to the PMOS current mirror module through the operational amplifier OP1 to realize the output of the constant drive current IOUT. In this embodiment, by changing the number of on-resistances, the bandgap reference voltage VBG is generated to generate a correctable reference voltage VREF2, and then a reference current is generated according to the reference voltage VREF2, and the desired constant drive current can also be obtained.

In the previous example, the reference voltage magnification can also be adjusted by adjusting the adjustable semiconductor resistance to achieve the current magnification adjustment function. Based on the foregoing embodiments, it can be seen that the adjustable semiconductor resistance can also be placed in the voltage generating module or the current generating module; and the correction and current ratio adjustment can be achieved by controlling the voltage generating module or controlling the current. The generation module is realized, as shown in Figure 11 and Figure 12. In FIG. 11, a specific implementation can realize the functions of reference voltage correction and magnification adjustment by connecting two sets of VREF2 generating circuits described in the previous paragraph in series.

Based on different embodiments, it can be seen that in the present invention, the internal resistance is the resistance in the semiconductor manufacturing process, especially the resistance with low temperature coefficient. Correct the resistance value or current mirror by correcting the control signal to ensure the accurate output of the reference current, and then adjust the output current according to the current magnification signal, so that the entire drive circuit can accurately output the required low temperature coefficient constant drive current . In terms of current magnification, different current mirrors can be used to cooperate to achieve the adjustment of magnification and the output of one or more sets of constant drive current. Therefore, there is no need to use external resistors in the present invention, which can effectively avoid various problems caused by external resistors. At the same time, through the correction and current magnification functions, it can effectively avoid the poor accuracy of semiconductor resistors and the inability to adjust resistance caused by internal resistors. The problem.

In an alternative embodiment, as shown in FIG. 13, the externally input calibration control signal and the current multiplier signal can be input from the same signal input terminal in a time-sharing manner, and connected to a shift register 130 for receiving It also temporarily stores various externally input signals. The shift register outputs the correction control signal to the aforementioned non-volatile memory, and sends the current rate signal to the aforementioned corresponding control circuit, so that the chip footprint can be simplified Realize the control of the drive circuit.

Further, in another alternative specific embodiment, as shown in FIGS. 14 and 15, the correction control signal or current multiplier signal signal output by the aforementioned shift register may be stored in a configuration register 140 first, and then The configuration register is transferred to the aforementioned non-volatile memory or drive circuit, which can reduce the repeated input of the same signal and simplify the control procedure. The calibration control signal output by the non-volatile memory can also be stored in a register first, and then output to the aforementioned corresponding calibration circuit, so that the non-volatile memory only needs to be read once after each power-on.

For the convenience of description, the above are only simple embodiments of the present invention and do not limit the present invention in any form. Although the present invention has been disclosed as simple embodiments, it is not intended to limit the present invention. Anyone familiar with the professional technology Personnel, without departing from the scope of the technical solution of the present invention, can make use of the above-disclosed technical content to make slight changes, or to change circuit combinations, or to modify equivalent embodiments with equivalent changes, but all that does not depart from the technical solution of the present invention Contents, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solutions of the present invention.

10: LED drive circuit

110: Constant current module

120: Non-volatile memory

150: signal input

160: drive current output

1130: Semiconductor resistance

Claims (10)

A driving circuit for LEDs, including; a signal input terminal for inputting the correction control signal and current multiplier signal from the external part; a semiconductor resistor, the resistor is made of a low temperature coefficient material, or made of two or more The material composition of the opposite temperature coefficient to achieve the effect of low temperature coefficient; a non-volatile memory used to store the externally input calibration control signal to calibrate the output current to a target value based on the calibration control signal value; The constant current module includes the semiconductor resistor for generating a constant drive current according to the calibration control signal stored in the non-volatile memory and the current rate signal provided by the outside; a drive current output terminal is used to output the constant Drive current. The driving circuit according to claim 1, wherein the constant current module specifically includes: a voltage generating module for providing a reference voltage; a current generating module including the semiconductor resistor, wherein the semiconductor resistor is Adjustable semiconductor resistance; the current generation module is used to adjust the semiconductor resistance according to the calibration control signal stored in the non-volatile memory, and according to the reference voltage, the adjusted semiconductor resistance value and the The current rate signal provided by the outside generates a constant drive current. The driving circuit according to claim 1, wherein the constant current module specifically includes: a voltage generating module for providing a reference voltage; a current generating module including the semiconductor resistor and current mirror circuit, according to The correction control signal of the non-volatile memory performs corrective fine-tuning of the current mirror to obtain a reference current according to the reference voltage and semiconductor resistance, and adjusts the current mirror magnification according to the externally provided current magnification signal to generate a constant drive current . The driving circuit according to claim 2, wherein the current generation module includes a correction unit and a magnification adjustment unit; wherein the correction unit includes an adjustable semiconductor resistor for adjusting according to the calibration stored in the non-volatile memory The positive control signal adjusts the resistance value of the semiconductor resistor; the magnification adjustment unit includes a current mirror circuit for obtaining a reference current according to the reference voltage and the adjusted resistance value of the semiconductor resistor and according to the externally provided The current rate signal performs rate adjustment on the reference current to generate a constant drive current. The driving circuit according to claim 1, wherein the constant current module includes: a voltage generating module, including the semiconductor resistor, wherein the semiconductor resistor is an adjustable semiconductor resistor, and the voltage generating module It is used to adjust the semiconductor resistor according to the calibration control signal stored in the non-volatile memory to adjust the required reference voltage; the current generating module includes a current mirror circuit to obtain the reference according to the reference voltage The current and the externally provided current magnification signal adjust the magnification of the reference current to generate a constant drive current. The driving circuit according to claim 3, 4, or 5, wherein the current mirror circuit is formed by a current mirror of one level or more than one current mirror connected in series; the input side of the current mirror circuit is used to obtain the reference current , The input side and/or the output side controls the conduction number of the transistors of each stage according to the current multiplier signal, so as to adjust the multiplier of the output constant drive current relative to the reference current. The driving circuit according to claim 4 or 5, wherein the semiconductor resistor includes a plurality of transistors and a plurality of resistors; the plurality of transistors are used to turn on and off according to a correction control signal to control the semiconductor The number of conductions in the resistor. The driving circuit according to claim 1, wherein the constant current module specifically includes: a voltage generating module including the semiconductor resistor, wherein the semiconductor resistor is an adjustable semiconductor resistor, and the voltage generating module The group is used to adjust the magnification of the semiconductor resistor according to the current magnification signal provided by the outside, and is used to adjust the required reference voltage; the current generating module includes a current mirror circuit, which is used to adjust the reference voltage and store in the non- The calibration control signal of the volatile memory adjusts the current mirror to generate a constant driving current. The driving circuit according to claim 1, wherein the constant current module includes: The voltage generating module includes the semiconductor resistor, wherein the semiconductor resistor is an adjustable semiconductor resistor, and the voltage generating module is used to perform a calibration control signal on the semiconductor resistor according to a calibration control signal stored in the non-volatile memory. Adjust, and adjust the magnification of another semiconductor resistor according to the current magnification signal provided by the outside to adjust the required reference voltage; the current generation module includes a current mirror circuit to obtain the reference current according to the reference voltage, To generate a constant drive current. The driving circuit according to claim 1, wherein the driving circuit further comprises: a shift register, the input terminal of which is electrically connected to the signal input terminal, for receiving and temporarily storing the calibration control of the external inputs Signal, and a current rate signal, and output the calibration control signal to the non-volatile memory.

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