Current driving device and display device

Abstract

The present disclosure provides a current driving device and a display device, belonging to the field of driving circuit technology. The current driving device of the present disclosure includes: a resistance adjustment circuit, a first feedback loop, and a second feedback loop; the resistance adjustment circuit is configured to control the on and off of switches in each voltage-dividing resistance branch in response to a control instruction to provide a total voltage-dividing resistance; the first feedback loop is configured to receive a first reference voltage, generate a reference current based on the total voltage-dividing resistance provided by the resistance adjustment circuit, and convert the reference current into an M-fold reference current, where M>1; the second feedback loop is configured to receive a second reference voltage of a first electrode of a light-emitting diode, and convert the M-fold reference current obtained by the first feedback loop into an M×N-fold reference current to provide a driving current to the light-emitting diode, where N>1.

Description

Technical Field

[0001] The present disclosure belongs to the technical field of drive circuits, and particularly relates to a current drive device and a display device. Background Art

[0002] Backlight technology is currently widely used in display devices in portable devices. Light-emitting diodes (LEDs) are increasingly popular as display backlights due to their low power consumption, high luminous efficiency, and long lifespan. LEDs require a current drive circuit to provide current, so an LED driver circuit is needed to achieve this function. A variety of current drive circuits are available on the market for driving LEDs used as backlights. These current drive circuits are suitable for different types of display devices using LEDs as backlights. However, different products have different performance requirements, making them not universally applicable.

[0003] Currently, commonly used current drive circuits and devices are not suitable for low-voltage scenarios, resulting in high power consumption on the motherboard and chip, affecting the user experience of display products and shortening the lifespan of the LEDs. Furthermore, the current accuracy of LEDs determines the quality of the display. Therefore, a current drive device is needed that can fine-tune the output current accuracy based on test results to improve the display quality of the display device. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art and provides a current driving device and a display device.

[0005] In a first aspect, an embodiment of the present disclosure provides a current driving device, the current driving device comprising: a resistance adjustment circuit, a first feedback loop, and a second feedback loop;

[0006] The resistance adjustment circuit is configured to control the on and off of switches in each voltage-dividing resistance branch in response to a control instruction to provide a total voltage-dividing resistance;

[0007] The first feedback loop is configured to receive a first reference voltage, generate a reference current according to a total voltage divider resistance provided by the resistance adjustment circuit, and convert the reference current into M times the reference current, where M>1;

[0008] The second feedback loop is configured to receive a second reference voltage of the first electrode of the light-emitting diode and convert the M-fold reference current obtained by the first feedback loop into an M×N-fold reference current to provide a driving current to the light-emitting diode, wherein N>1.

[0009] Wherein, the first feedback loop includes a first operational amplifier and a first mirror sub-circuit;

[0010] The non-inverting input terminal of the first operational amplifier is electrically connected to the first reference voltage terminal, and the inverting input terminal of the first operational amplifier is electrically connected to the first terminal of the resistance adjustment circuit and the first terminal of the mirror sub-circuit;

[0011] The first mirror sub-circuit is configured to mirror the reference current and convert the reference current into M times the reference current.

[0012] The first mirror sub-circuit includes a first transistor and a second transistor, the second electrode of the first transistor is electrically connected to the inverting input terminal of the first operational amplifier and the first terminal of the resistance adjustment circuit, and the second electrode of the first transistor serves as the first terminal of the first mirror sub-circuit;

[0013] The control electrode of the second transistor is electrically connected to the second electrode thereof and the control electrode of the first transistor, the first electrode of the second transistor is electrically connected to the first electrode of the first transistor, and the second electrode of the second transistor is electrically connected to the second feedback loop.

[0014] Wherein, the second feedback loop includes a second operational amplifier and a second mirror sub-circuit;

[0015] The non-inverting input terminal of the second operational amplifier is electrically connected to the second reference voltage terminal of the light-emitting diode, and the inverting input terminal of the second operational amplifier is electrically connected to the first terminal of the second mirror sub-circuit;

[0016] The second mirror sub-circuit is configured to mirror M times the reference current and convert the M times the reference current into M×N times the reference current.

[0017] The second feedback loop further includes a third transistor; a first electrode of the third transistor is electrically connected to the first feedback loop, and a second electrode of the third transistor is electrically connected to the first end of the second mirror sub-circuit; the control electrode is electrically connected to the output end of the second operational amplifier and is turned on or off by an output signal from the output end of the second operational amplifier.

[0018] The second mirror sub-circuit includes a fourth transistor and a fifth transistor, a first electrode of the fourth transistor is electrically connected to the first electrode of the fifth transistor, a second electrode of the fourth transistor is electrically connected to the second electrode of the third transistor and the inverting input terminal of the second operational amplifier; a second electrode of the fifth transistor is electrically connected to the non-inverting input terminal of the second operational amplifier, and a control electrode of the fifth transistor is electrically connected to the control electrode of the fourth transistor and is electrically connected to the first feedback loop.

[0019] The control electrodes of the fourth transistor and the fifth transistor are electrically connected to the output terminal of the first operational amplifier of the first feedback loop, and are turned on or off according to the output signal of the output terminal of the first operational amplifier.

[0020] The resistance adjustment circuit includes X voltage-dividing resistor branches, where X≥1; the voltage-dividing resistor branches include voltage-dividing resistors and switching transistors connected in parallel; the first end of the resistance adjustment circuit is electrically connected to the first feedback loop, and the second end of the resistance adjustment circuit is electrically connected to the third reference voltage end.

[0021] Wherein, the resistance adjustment circuit further includes a register;

[0022] The register is electrically connected to the control electrodes of the switch transistors of X voltage-dividing resistor branches and is configured to control the switch transistors of Y voltage-dividing resistor branches to be in an on state according to a preset value, wherein X≥1 and X≥Y.

[0023] In a second aspect, an embodiment of the present disclosure provides a current driving device, which includes a first feedback loop, a second feedback loop, and a resistance adjustment circuit;

[0024] The first feedback loop includes a first operational amplifier and a first mirror subcircuit; the first mirror subcircuit includes a first transistor and a second transistor;

[0025] The second feedback loop includes a second operational amplifier, a second mirror sub-circuit and a third transistor; the second mirror sub-circuit includes a fourth transistor and a fifth transistor;

[0026] The resistance adjustment circuit includes X voltage-dividing resistor branches, each of which includes voltage-dividing resistors and switching transistors connected in parallel; a first end of the resistance adjustment circuit is electrically connected to the inverting input terminal of the first operational amplifier and the second electrode of the first transistor, and a second end of the resistance adjustment circuit is electrically connected to the third reference voltage terminal;

[0027] The non-inverting input terminal of the first operational amplifier is electrically connected to the first reference voltage terminal, the inverting input terminal is electrically connected to the voltage divider resistor of the resistance adjustment circuit and the second electrode of the first transistor, and the output terminal is electrically connected to the control electrodes of the fourth transistor and the fifth transistor; the first electrode of the first transistor is electrically connected to the first electrode of the second transistor; the control electrode of the second transistor is electrically connected to its second electrode and the control electrode of the first transistor, and the second electrode of the second transistor is electrically connected to the first electrode of the third transistor; the second electrode of the third transistor is electrically connected to the second electrode of the fourth transistor and the inverting input terminal of the second operational amplifier, and the control electrode of the third transistor is electrically connected to the output terminal of the second operational amplifier; the first electrode of the fourth transistor is electrically connected to the first electrode of the fifth transistor; the second electrode of the fifth transistor is electrically connected to the second reference voltage terminal and the non-inverting input terminal of the second operational amplifier.

[0028] Among them, the first transistor and the second transistor have the same conduction characteristics; the third transistor, the fourth transistor and the fifth transistor have the same conduction characteristics; the first transistor, the second transistor and the third transistor, the fourth transistor and the fifth transistor have different conduction characteristics.

[0029] In a third aspect, an embodiment of the present disclosure further provides a display device, which includes any one of the current driving devices described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of a current driving device provided in an embodiment of the present disclosure.

[0031] Figure 2 A schematic diagram of a first feedback loop provided in an embodiment of the present disclosure.

[0032] Figure 3 A schematic diagram of a second feedback loop provided in an embodiment of the present disclosure.

[0033] Figure 4 A schematic diagram of a resistance adjustment circuit provided in an embodiment of the present disclosure.

[0034] Figure 5 A schematic diagram of the specific structure of the current driving device provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0036] Unless otherwise defined, the technical or scientific terms used in this disclosure should have the usual meanings understood by people with ordinary skills in the field to which this disclosure belongs. The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one", "an" or "the" do not indicate a quantity limitation, but rather indicate the existence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0037] Existing LED current drive devices are not suitable for low-voltage scenarios, resulting in high power consumption of the motherboard and chip, affecting the user experience of screen display products and shortening the lifespan of the LEDs. Furthermore, the current accuracy of LEDs determines the quality of the display. Therefore, a current drive device that can fine-tune the output current accuracy based on test results is needed to improve the display quality of the display device.

[0038] In view of this, the present disclosure provides a current driving device and a display device. The current driving device provided in the present disclosure includes a feedback loop and a resistance adjustment circuit. The feedback loop includes an operational amplifier and a mirror circuit to amplify the current under a constant voltage. The resistance adjustment circuit can fine-tune the current provided by the current driving device by changing the resistance of its equivalent resistor.

[0039] The current driving device and the display device provided by the present disclosure are further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] In a first aspect, an embodiment of the present disclosure provides a current driving device, Figure 1 A schematic diagram of a current driving device provided in an embodiment of the present disclosure, such as Figure 1As shown, the current driving device includes: a resistance adjustment circuit 3, a first feedback loop 1, and a second feedback loop 2. The resistance adjustment circuit 3 is configured to control the on and off of the switches in each voltage-dividing resistance branch in response to a control instruction to provide a total voltage-dividing resistance. The first feedback loop 1 is configured to receive a first reference voltage, generate a reference current according to the total voltage-dividing resistance provided by the resistance adjustment circuit 3, and convert the reference current into an M-fold reference current, where M>1. The second feedback loop 2 is configured to receive a second reference voltage of the first electrode of the light-emitting diode D1, and convert the M-fold reference current obtained by the first feedback loop 1 into an M×N-fold reference current to provide a driving current to the light-emitting diode D1, where N>1. In the embodiment of the present disclosure, the first electrode of the light-emitting diode D1 is a cathode, the second reference voltage is the cathode voltage of the light-emitting diode D1, and the anode of the light-emitting diode D1 is connected to the driving voltage VDD.

[0041] Specifically, the resistance adjustment circuit 3 includes multiple voltage-dividing resistor branches, each including a resistor and a transistor connected in parallel therewith. The transistor functions as a switch. When the transistor is on, the voltage-dividing resistor connected in parallel with the transistor is short-circuited, and the total voltage-dividing resistor value of the resistance adjustment circuit 3 decreases. Conversely, when the transistor is off, the voltage-dividing resistor connected in parallel with the transistor is not short-circuited, and the total voltage-dividing resistor value of the resistance adjustment circuit 3 increases. The above method is used to adjust the resistance value of the resistors. The following example illustrates the total voltage-dividing resistor value R and the first reference voltage value VREF. A first feedback loop 1 generates a reference current based on the total voltage-dividing resistor value provided by the resistance adjustment circuit 3 and the first reference voltage. According to the Ampere formula, the reference current is VREF / R. After obtaining the reference current, the first feedback loop 1 amplifies the reference current by M times, resulting in a magnitude of M×VREF / R. A second feedback loop 2 amplifies the M-fold reference current by N times, resulting in a magnitude of N×M×VREF / R.

[0042] The current drive device of the present embodiment incorporates a resistance adjustment circuit 3. By adjusting the on / off states of the transistors in each voltage-dividing resistor branch within the resistance adjustment circuit 3, the total voltage-dividing resistance is adjusted, thereby varying the reference current and enabling precise fine-tuning of the drive current. Simultaneously, the first feedback loop 1 and the second feedback loop 2 increase the drive current without changing the voltage. This increases the drive current without increasing additional power, enabling sufficient current to be supplied to the LED for driving at low voltage.

[0043] The transistors used in the embodiments of the present disclosure may be thin film transistors or field effect transistors or other devices with the same characteristics. Since the source and drain of the transistors used are symmetrical, there is no difference between the source and drain. In the embodiments of the present disclosure and the subsequent description, in order to distinguish the source and drain of the transistor, one of the electrodes is referred to as the first electrode, the other electrode is referred to as the second electrode, and the gate is referred to as the control electrode. In addition, according to the characteristics of the transistor, the transistor can be divided into N-type and P-type. When a P-type transistor is used, the first electrode is the source of the P-type transistor, the second electrode is the drain of the P-type transistor, and when a low-level signal is input to the gate, the source and drain are turned on; when an N-type transistor is used, the first electrode is the source of the N-type transistor, the second electrode is the drain of the N-type transistor, and when a high-level signal is input to the gate, the source and drain are turned on.

[0044] In some examples, Figure 2 A schematic diagram of a first feedback loop provided in an embodiment of the present disclosure is shown in FIG. Figure 2 As shown, the first feedback loop 1 includes a first operational amplifier A1 and a first mirror sub-circuit 11. The non-inverting input of the first operational amplifier A1 is electrically connected to the first reference voltage terminal Vss1, and the inverting input of the first operational amplifier A1 is electrically connected to both the first terminal of the resistance adjustment circuit 3 and the first terminal of the mirror sub-circuit. The first mirror sub-circuit 11 is configured to mirror a reference current and convert the reference current into M times the reference current. The voltage at the non-inverting input of the first operational amplifier A1 is the same as the voltage at the inverting input. Therefore, after the first reference voltage is input to the non-inverting input, the voltage at the inverting input is VREF. The voltage at the node connecting the inverting input of the first operational amplifier A1 and the first terminal of the resistance adjustment circuit 3 is also VREF. Since the total voltage divider resistance is R, the reference current is VREF / R. A first end of the first mirror sub-circuit 11 is electrically connected to the inverting input terminal of the first operational amplifier A1 and the first end of the resistance adjustment circuit 3. The voltage at the first end of the first mirror sub-circuit 11 is VREF, and the current is VREF / R. The first mirror sub-circuit 11 amplifies the reference current by M times. Therefore, the voltage at the second end of the first mirror sub-circuit 11 is VREF, and the current is M×VREF / R.

[0045] In some examples, such as Figure 2 As shown, the first mirror sub-circuit 11 includes a first transistor P1 and a second transistor P2. The second electrode of the first transistor P1 is electrically connected to the inverting input terminal of the first operational amplifier A1 and the first terminal of the resistance adjustment circuit 3, wherein the second electrode of the first transistor P1 serves as the first terminal of the first mirror sub-circuit 11; the control electrode of the second transistor P2 is electrically connected to the second electrode thereof and the control electrode of the first transistor P1, the first electrode of the second transistor P2 is electrically connected to the first electrode of the first transistor P1, and the second electrode of the second transistor P2 is electrically connected to the second feedback loop 2.

[0046] Specifically, the second electrode of the first transistor P1 and the second electrode of the second transistor P2 have the same voltage. Since the voltage applied to the first terminal of the resistance adjustment circuit 3 is VREF, the second electrode of the first transistor P1 serves as the first terminal of the first mirror sub-circuit 11. The first terminal of the first mirror sub-circuit 11 has the same voltage as the first terminal of the resistance adjustment circuit 3. Therefore, the voltages of the second electrodes of the first transistor P1 and the second electrodes of the second transistor P2 are equal to VREF. To ensure a 1:M current ratio between the second electrodes of the first transistor P1 and the second electrodes of the second transistor P2, the width-to-length ratio of the first transistor P1 and the second transistor P2 should be 1:M when fabricating or selecting the first transistor P1 and the second transistor P2. The second electrode of the second transistor P2 serves as the second terminal of the first mirror sub-circuit 11 and is electrically connected to the second feedback loop 2.

[0047] In some examples, Figure 3 A schematic diagram of a second feedback loop provided in an embodiment of the present disclosure is shown in FIG. Figure 3 As shown, the second feedback loop 2 includes a second operational amplifier A2 and a second mirror sub-circuit 22. The non-inverting input of the second operational amplifier A2 is electrically connected to the second reference voltage terminal Vss2 of the light-emitting diode D1, and the inverting input of the second operational amplifier A2 is electrically connected to the first terminal of the second mirror sub-circuit 22. The second mirror sub-circuit 22 is configured to mirror an M-fold reference current and convert the M-fold reference current into an M×N-fold reference current. The voltage at the non-inverting input and the inverting input of the second operational amplifier A2 are the same. Therefore, after the second reference voltage is input to the non-inverting input, the voltage at the inverting input is also the same as the second reference voltage. The inverting input of the second operational amplifier A2 is electrically connected to the first terminal of the second mirror sub-circuit 22, and the second terminal of the second mirror sub-circuit 22 is electrically connected to the non-inverting input of the second operational amplifier A2. The voltage at the first and second terminals of the second mirror sub-circuit 22 is the same, both being the second reference voltage. The second mirror sub-circuit 22 amplifies the M-fold reference current by N times again, thereby obtaining an M×N-fold reference current of N×M×VREF / R.

[0048] In some examples, such as Figure 3 As shown, the second feedback loop 2 further includes a third transistor N1; a first electrode of the third transistor N1 is electrically connected to the first feedback loop 1, a second electrode of the third transistor N1 is electrically connected to the first end of the second mirror sub-circuit 22, and a control electrode is electrically connected to the output end of the second operational amplifier A2. Specifically, the first electrode of the third transistor N1 is electrically connected to the second end of the first mirror sub-circuit 11, and the control electrode of the third transistor N1 is used to receive the electrical signal output by the output end of the second operational amplifier A2 and is turned on or off under the control of the output signal of the output end of the second operational amplifier A2.

[0049] In some examples, such as Figure 3 As shown, the second mirror sub-circuit 22 includes a fourth transistor N2 and a fifth transistor N3. The first electrode of the fourth transistor N2 is electrically connected to the first electrode of the fifth transistor N3. The second electrode of the fourth transistor N2 is electrically connected to the second electrode of the third transistor N1 and the inverting input terminal of the second operational amplifier A2. The second electrode of the fifth transistor N3 is electrically connected to the non-inverting input terminal of the second operational amplifier A2. The control electrode of the fifth transistor N3 is electrically connected to the control electrode of the fourth transistor N2 and is electrically connected to the first feedback loop 1.

[0050] Specifically, the second electrode of the fourth transistor N2 is electrically connected to the second electrode of the third transistor N1 and the inverting input terminal of the second operational amplifier A2. The voltage at the second electrode of the fifth transistor N3 and the voltage at the second operational amplifier A2 are both equal to the second reference voltage. The voltage at the inverting input terminal of the second operational amplifier A2 is equal to the voltage at the non-inverting input terminal. Therefore, the voltage at the second electrode of the fourth transistor N2 and the second electrode of the fifth transistor N3 are equal to the second reference voltage. The current at the second electrode of the fourth transistor N2 is M×VREF / R. To achieve a 1:N current ratio between the second electrode of the fourth transistor N2 and the second electrode of the fifth transistor N3, the width-to-length ratio of the fourth transistor N2 and the fifth transistor N3 should be 1:N when fabricating or selecting the fourth transistor N2 and the fifth transistor N3. The second electrode of the fifth transistor N3 serves as the second terminal of the second mirror sub-circuit 22 and is electrically connected to the second operational amplifier A2 and the second reference voltage terminal Vss2.

[0051] In some examples, such as Figure 3 As shown, the control electrodes of the fourth transistor N2 and the fifth transistor N3 are electrically connected to the output terminal of the first operational amplifier A1 of the first feedback loop 1. The control electrodes of the fourth transistor N2 and the fifth transistor N3 are used to receive the electrical signal output from the output terminal of the first operational amplifier A1, and are turned on or off under the control of the output signal of the output terminal of the first operational amplifier A1.

[0052] In some examples, Figure 4 A schematic diagram of a resistance adjustment circuit provided in an embodiment of the present disclosure is shown in FIG. Figure 4 As shown, the resistance adjustment circuit 3 includes X voltage-dividing resistance branches, where X ≥ 1; the voltage-dividing resistance branches include parallel voltage-dividing resistors and switching transistors; the first end of the resistance adjustment circuit 3 is connected to the first feedback loop 1, and the second end of the resistance adjustment circuit 3 is connected to the third reference voltage terminal Vss3, and the third reference voltage terminal Vss3 includes but is not limited to the ground terminal.

[0053] Furthermore, the resistance adjustment circuit 3 also includes a register 33; the register 33 is electrically connected to the control electrodes of the switching transistors of the X voltage-dividing resistor branches. The register 33 is configured to send a control signal to the Y voltage-dividing resistor branches according to a preset value, controlling the switching transistors of the Y voltage-dividing resistor branches to be in an on state, where X ≥ 1 and X ≥ Y. A test process is added during production and manufacturing. After the current driving device is connected to the LED and operates, the current at the first end of the resistance adjustment circuit 3 is tested. Based on the test results and the actual current demand of the LED, the preset value Y in the register 33 is obtained. Since the switching transistors and the voltage-dividing resistors of each voltage-dividing resistor branch are connected in parallel, when the switching transistor is in the on state, the corresponding voltage-dividing resistor of the switching transistor in the on state is short-circuited in the resistance adjustment circuit 3, that is, it does not play a voltage-dividing role; conversely, when the switching transistor is in the off state, the corresponding voltage-dividing resistor of the switching transistor in the off state plays a voltage-dividing role in the resistance adjustment circuit 3. The register 33 controls the switching transistors of the XY voltage-dividing resistor branches on the resistance adjustment circuit 3 to be in the off state and the switching transistors of the Y voltage-dividing resistor branches to be in the on state according to the preset value of Y stored in the register. The sizes of the various voltage-dividing resistors can be the same or different. When the sizes of the various voltage-dividing resistors are the same, taking the voltage-dividing resistor size R1 as an example, the total voltage-dividing resistor size of the resistance adjustment circuit 3 is (XY)×R1. By changing the preset value in the register 33, the resistance value of the total voltage-dividing resistor is changed, and the driving current can be accurately fine-tuned, further realizing that the current driving device can be used to drive various devices without causing high power consumption. For example, when used to drive LED light-emitting devices of different colors or different models, the driving current size is different. After testing, a suitable current size is obtained, and the value of Y is obtained based on the current size, and then the actual voltage-dividing resistor size in the resistance adjustment circuit 3 is obtained. The register 33 can control the switching transistors corresponding to each resistance voltage dividing branch near the first end of the resistance adjustment circuit 3 to turn on according to a preset value, and can also control the switching transistors corresponding to each resistance voltage dividing branch near the second end of the resistance adjustment circuit 3 to turn on, and can also turn on the switching transistors corresponding to the resistance voltage dividing branches at intervals, without further limitation here.

[0054] In order to make the structure and working principle of the continuous voltage comparison device in the embodiment of the present disclosure clearer, the following description is given with reference to specific examples. Figure 5 A schematic diagram of the specific structure of the current driving device provided in the embodiment of the present disclosure, such as Figure 5As shown, the current driving device includes a first feedback loop 1, a second feedback loop 2, and a resistance adjustment circuit 3. The first feedback loop 1 includes: a first operational amplifier A1; a first mirror sub-circuit 11; the non-inverting input terminal of the first operational amplifier A1 is electrically connected to the first reference voltage terminal Vss1; the non-inverting input terminal and the inverting input terminal of the first operational amplifier circuit have the same voltage, which is the reference voltage VREF input to the first reference voltage terminal Vss1; the first mirror sub-circuit 11 includes a first transistor P1 and a second transistor P2; the second electrode of the first transistor P1 is electrically connected to the inverting input terminal of the first operational amplifier A1 and the first terminal of the resistance adjustment circuit 3; the control electrode of the second transistor P2 is electrically connected to the second electrode of the second transistor P2 and the control electrode of the first transistor P1; the first electrode of the second transistor P2 is electrically connected to the first electrode of the first transistor P1; and the second electrode of the second transistor P2 is electrically connected to the second feedback loop 2. The second feedback loop 2 includes: a second operational amplifier A2, a second mirror sub-circuit 22; the non-inverting input terminal of the second operational amplifier A2 is electrically connected to the second reference voltage terminal Vss2 of the light-emitting diode D1, the non-inverting input terminal and the inverting input terminal of the second operational amplifier circuit have the same voltage, and are both the second reference voltage input to the second reference voltage terminal Vss2; the second mirror sub-circuit 22 includes a fourth transistor N2 and a fifth transistor N3, the first electrode of the fourth transistor N2 is electrically connected to the first electrode of the fifth transistor N3, the second electrode of the fourth transistor N2 is electrically connected to the second electrode of the third transistor N1 and the inverting input terminal of the second operational amplifier A2; the second electrode of the fifth transistor N3 is electrically connected to the non-inverting input terminal of the second operational amplifier A2, and the control electrode of the fifth transistor N3 is electrically connected to the control electrode of the fourth transistor N2. The control electrode of transistor N2 is electrically connected to the first feedback loop 1; the control electrodes of the fourth transistor N2 and the fifth transistor N3 are electrically connected to the output terminal of the first operational amplifier A1 of the first feedback loop 1, and the control electrodes of the fourth transistor N2 and the fifth transistor N3 are used to receive the electrical signal output by the output terminal of the first operational amplifier A1, and are turned on or off under the control of the output signal of the output terminal of the first operational amplifier A1; the second feedback loop 2 also includes a third transistor N1; the first electrode of the third transistor N1 is electrically connected to the first feedback loop 1, the second electrode of the third transistor N1 is electrically connected to the first terminal of the second mirror sub-circuit 22; the control electrode of the third transistor N1 is electrically connected to the output terminal of the second operational amplifier A2, and is turned on or off under the control of the output signal of the output terminal of the second operational amplifier A2.The resistance adjustment circuit 3 includes: X voltage-dividing resistor branches, each voltage-dividing resistor branch includes parallel voltage-dividing resistors (R01 to R0X) and switching transistors (T01 to T0X); the control electrode of the switching transistor of each voltage-dividing resistor branch is connected to a register 33; the register 33 is configured to control the switching transistors of Y voltage-dividing resistor branches to be in an on state according to a preset value, where X ≥ 1 and X ≥ Y; when the resistance values of the voltage-dividing resistors in each voltage-dividing resistor branch are the same, the total voltage-dividing resistance of the resistance adjustment circuit 3 is (XY) × R1.

[0055] Continue to refer to Figure 5 The non-inverting input of the first operational amplifier A1 receives the first reference voltage from the first reference circuit. The voltages of the non-inverting input and the inverting input of the first operational amplifier A1 are the same, both having a magnitude of the first reference voltage VREF. The inverting input of the first operational amplifier A1 is electrically connected to the resistance adjustment circuit 3. The magnitude of the reference current at the connection point between the inverting input of the first operational amplifier A1 and the second electrode of the first transistor P1 in the first mirror sub-circuit 11 is VREF / R, where R=(XY)×R1. After the reference current passes through the first mirror sub-circuit 11 and is amplified M times, the current magnitude is M×VREF / R. The second feedback loop 2 further amplifies the M-fold amplified reference current, and after passing through the second mirror sub-circuit 22 and amplifying it N times, the current magnitude is N×M×VREF / R. The resulting N×M-fold reference current is the driving current used to drive the LED in the embodiment of the present disclosure.

[0056] In a second aspect, an embodiment of the present disclosure provides a current driving device, which includes a first feedback loop 1, a second feedback loop 2 and a resistance adjustment circuit 1; the first feedback loop 1 includes a first operational amplifier A1 and a first mirror sub-circuit 11; the first mirror sub-circuit 11 includes a first transistor P1 and a second transistor P2; the second feedback loop 2 includes a second operational amplifier A2, a second mirror sub-circuit 22 and a third transistor N1; the second mirror sub-circuit includes a fourth transistor N2 and a fifth transistor N3; the resistance adjustment circuit 3 includes X voltage-dividing resistor branches, each voltage-dividing resistor branch includes a parallel voltage-dividing resistor and a switching transistor; a first end of the resistance adjustment circuit 3 is electrically connected to the inverting input terminal of the first operational amplifier A1 and the second electrode of the first transistor P1, and a second end of the resistance adjustment circuit 3 is electrically connected to the third reference voltage terminal Vss3; the non-inverting input terminal of the first operational amplifier A1 is electrically connected to the first reference voltage terminal Vss3. The voltage terminal Vss1 is electrically connected, the inverting input terminal is electrically connected to the voltage divider resistor of the resistance adjustment circuit 3 and the second electrode of the first transistor P1, and the output terminal is electrically connected to the control electrodes of the fourth transistor N2 and the fifth transistor N3; the first electrode of the first transistor P1 is electrically connected to the first electrode of the second transistor P2; the control electrode of the second transistor P2 is electrically connected to its second electrode and the control electrode of the first transistor P1, and the second electrode of the second transistor P2 is electrically connected to the first electrode of the third transistor N1; the second electrode of the third transistor N1 is electrically connected to the second electrode of the fourth transistor N2 and the inverting input terminal of the second operational amplifier A2, and the control electrode of the third transistor N1 is electrically connected to the output terminal of the second operational amplifier A2; the first electrode of the fourth transistor N2 is electrically connected to the first electrode of the fifth transistor N3; the second electrode of the fifth transistor N3 is electrically connected to the second reference voltage terminal Vss2 and the non-inverting input terminal of the second operational amplifier A2.

[0057] In some examples, the first transistor P1 and the second transistor P2 have the same conduction characteristics; the third transistor N1, the fourth transistor N2, and the fifth transistor N3 have the same conduction characteristics; the first transistor P1 and the second transistor P2 have different conduction characteristics from the third transistor N1, the fourth transistor N2, and the fifth transistor N3. The first transistor P1 and the second transistor P2 are P-type transistors; the third transistor N1, the fourth transistor N2, and the fifth transistor N3 are N-type transistors.

[0058] In a third aspect, embodiments of the present disclosure further provide a display device comprising the aforementioned current driving device and a light-emitting diode D1. Specifically, the current driving device is configured to drive the light-emitting diode D1, and the magnitude of the driving current can be fine-tuned based on the color and type of the light-emitting diode D1, while maintaining the magnitude of the driving current without increasing additional power consumption.

[0059] It will be understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present invention, and the present invention is not limited thereto. Those skilled in the art will appreciate that various modifications and improvements can be made without departing from the spirit and substance of the present invention, and such modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A current driving device, characterized in that: The current driving device includes: a resistance adjustment circuit, a first feedback loop and a second feedback loop; The resistance adjustment circuit is configured to control the on and off of switches in each voltage-dividing resistance branch in response to a control instruction to provide a total voltage-dividing resistance; The first feedback loop is configured to receive a first reference voltage, generate a reference current according to a total voltage divider resistance provided by the resistance adjustment circuit, and convert the reference current into M times the reference current, where M>1; The second feedback loop is configured to receive a second reference voltage of the first electrode of the light-emitting diode and convert the M-fold reference current obtained by the first feedback loop into an M×N-fold reference current to provide a driving current to the light-emitting diode, wherein N>1; The first feedback loop includes a first operational amplifier and a first mirror sub-circuit; a non-inverting input terminal of the first operational amplifier is electrically connected to a first reference voltage terminal, an inverting input terminal of the first operational amplifier is electrically connected to a first terminal of the resistance adjustment circuit and a first terminal of the first mirror sub-circuit, and an output terminal of the first operational amplifier is electrically connected to a second mirror sub-circuit; the first mirror sub-circuit is configured to mirror the reference current and convert the reference current into M times the reference current; The second feedback loop includes a second operational amplifier, a second mirror sub-circuit, and a third transistor; a non-inverting input terminal of the second operational amplifier is electrically connected to the second reference voltage terminal of the light-emitting diode, a non-inverting input terminal of the second operational amplifier is electrically connected to the second terminal of the second mirror sub-circuit, and an inverting input terminal of the second operational amplifier is electrically connected to the first terminal of the second mirror sub-circuit; the second mirror sub-circuit is electrically connected to the second reference voltage terminal of the light-emitting diode and is configured to mirror an M-fold reference current and convert the M-fold reference current into an M×N-fold reference current; A first electrode of the third transistor is electrically connected to the first feedback loop, and a second electrode of the third transistor is electrically connected to the first end of the second mirror sub-circuit; a control electrode of the third transistor is electrically connected to the output end of the second operational amplifier, and is turned on or off according to an output signal from the output end of the second operational amplifier.

2. The current driving device according to claim 1, characterized in that: The first mirror sub-circuit includes a first transistor and a second transistor, the second electrode of the first transistor is electrically connected to the inverting input terminal of the first operational amplifier and the first terminal of the resistance adjustment circuit, wherein the second electrode of the first transistor serves as the first terminal of the first mirror sub-circuit; The control electrode of the second transistor is electrically connected to the second electrode thereof and the control electrode of the first transistor, the first electrode of the second transistor is electrically connected to the first electrode of the first transistor, and the second electrode of the second transistor is electrically connected to the second feedback loop.

3. The current driving device according to claim 1, wherein: The second mirror sub-circuit includes a fourth transistor and a fifth transistor, wherein a first electrode of the fourth transistor is electrically connected to a first electrode of the fifth transistor, a second electrode of the fourth transistor is electrically connected to a second electrode of the third transistor, and an inverting input terminal of the second operational amplifier; a second electrode of the fifth transistor is electrically connected to a non-inverting input terminal of the second operational amplifier, and a control electrode of the fifth transistor is electrically connected to a control electrode of the fourth transistor and to a first feedback loop.

4. The current driving device according to claim 3, characterized in that: The control electrodes of the fourth transistor and the fifth transistor are electrically connected to the output terminal of the first operational amplifier of the first feedback loop, and are turned on or off according to the output signal of the output terminal of the first operational amplifier.

5. The current driving device according to claim 1, wherein: The resistance adjustment circuit includes X voltage-dividing resistance branches, where X≥1; the voltage-dividing resistance branches include voltage-dividing resistors and switching transistors connected in parallel; the first end of the resistance adjustment circuit is electrically connected to the first feedback loop, and the second end of the resistance adjustment circuit is electrically connected to the third reference voltage end.

6. The current driving device according to claim 5, characterized in that: The resistance adjustment circuit further includes a register; The register is electrically connected to the control electrodes of the switch transistors of X voltage-dividing resistor branches and is configured to control the switch transistors of Y voltage-dividing resistor branches to be in an on state according to a preset value, wherein X≥1 and X≥Y.

7. A current driving device, characterized in that: It includes a first feedback loop, a second feedback loop and a resistance adjustment circuit; The first feedback loop includes a first operational amplifier and a first mirror subcircuit; the first mirror subcircuit includes a first transistor and a second transistor; The second feedback loop includes a second operational amplifier, a second mirror sub-circuit and a third transistor; the second mirror sub-circuit includes a fourth transistor and a fifth transistor; The resistance adjustment circuit includes X voltage-dividing resistor branches, each of which includes voltage-dividing resistors and switching transistors connected in parallel; a first end of the resistance adjustment circuit is electrically connected to the inverting input terminal of the first operational amplifier and the second electrode of the first transistor, and a second end of the resistance adjustment circuit is electrically connected to the third reference voltage terminal; The non-inverting input terminal of the first operational amplifier is electrically connected to the first reference voltage terminal, the inverting input terminal is electrically connected to the voltage divider resistor of the resistance adjustment circuit and the second electrode of the first transistor, and the output terminal is electrically connected to the control electrodes of the fourth transistor and the fifth transistor; the first electrode of the first transistor is electrically connected to the first electrode of the second transistor; the control electrode of the second transistor is electrically connected to its second electrode and the control electrode of the first transistor, and the second electrode of the second transistor is electrically connected to the first electrode of the third transistor; the second electrode of the third transistor is electrically connected to the second electrode of the fourth transistor and the inverting input terminal of the second operational amplifier, and the control electrode of the third transistor is electrically connected to the output terminal of the second operational amplifier; the first electrode of the fourth transistor is electrically connected to the first electrode of the fifth transistor; the second electrode of the fifth transistor is electrically connected to the second reference voltage terminal and the non-inverting input terminal of the second operational amplifier.

8. The current driving device according to claim 7, characterized in that: The first transistor and the second transistor have the same conduction characteristics; the third transistor, the fourth transistor and the fifth transistor have the same conduction characteristics; the first transistor, the second transistor and the third transistor, the fourth transistor and the fifth transistor have different conduction characteristics.

9. A display device, characterized in that: The display device comprises the current driving device according to any one of claims 1 to 8.

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