Channel current calibration circuit of LED driver chip and LED driver chip

Abstract

The present invention provides a channel current calibration circuit for an LED driver chip and an LED driver chip, comprising: a calibration voltage generation module and multiple channel calibration selection modules. The calibration voltage generation module is configured to receive a first reference voltage generated by a reference voltage generation module and adjust the first reference voltage according to a preset voltage difference to obtain multiple calibration voltages, wherein the voltage difference between adjacent calibration voltages is the preset voltage difference. The channel calibration selection module is configured to receive the multiple calibration voltages and select a target calibration voltage from the multiple calibration voltages according to a first control signal from a digital controller, thereby calibrating the output current of the channel current generation module to a desired current value using the target calibration voltage. After the calibration voltage generation module adjusts the reference voltage to multiple calibration voltages, each channel calibration selection module selects the corresponding target calibration voltage to adjust the output current of the corresponding channel current generation module to the desired value.

Description

Technical Field

[0001] The present invention relates to the technical field of current correction, and in particular to a channel current calibration circuit of an LED driver chip and the LED driver chip. Background Art

[0002] Currently, due to the deviations in manufacturing process, packaging process and other aspects between different LED driver chips, the actual output current of different channels in the current generation circuits of multiple channels in these LED driver chips will deviate from each other when they are working. In addition to the above reasons, the current tubes used in different channels are in different positions in the topology layout, and the process deviations will also cause deviations in the actual output current of different channels. In addition, the input voltage error (V in Different offsets can also cause deviations in the output currents of different channels. Therefore, how to resolve the output current deviations between the current generating circuits of different channels in the LED driver chip has become a technical problem that needs to be solved urgently.

[0003] In summary, the existing LED driver chip has a technical problem of inconsistent output currents between current generating circuits in different channels. Summary of the Invention

[0004] The object of the present invention is to provide a channel current calibration circuit for an LED driver chip and an LED driver chip, so as to alleviate the technical problem of inconsistent output currents between different channel current generating circuits in the existing LED driver chip.

[0005] In a first aspect, the present invention provides a channel current calibration circuit for an LED driver chip, comprising: a calibration voltage generating module and a plurality of channel calibration selection modules;

[0006] The first end of the calibration voltage generating module is connected to the reference voltage generating module of the LED driver chip, the second end of the calibration voltage generating module is connected to the first ends of the plurality of channel calibration selection modules, the second end of each of the channel calibration selection modules is respectively connected to the digital controller of the LED display device, and the third end of each of the channel calibration selection modules is respectively connected to a channel current generating module of the LED driver chip;

[0007] The calibration voltage generating module is configured to receive the first reference voltage generated by the reference voltage generating module and adjust the first reference voltage according to a preset voltage difference to obtain a plurality of calibration voltages, wherein the voltage difference between adjacent calibration voltages is the preset voltage difference;

[0008] The channel calibration selection module is used to receive the multiple calibration voltages and select a target calibration voltage from the multiple calibration voltages according to the first control signal of the digital controller, so as to calibrate the output current of the channel current generation module to a desired current value through the target calibration voltage.

[0009] Furthermore, the calibration voltage generating module includes: a resistance module consisting of a first operational amplifier, a first field effect transistor, and a plurality of resistors connected in series;

[0010] The negative input terminal of the first operational amplifier is connected to the reference voltage generating module, the positive input terminal of the first operational amplifier is connected to one end of any resistor in the resistance module, and the output terminal of the first operational amplifier is connected to the first end of the first field effect transistor;

[0011] The second end of the first field effect transistor is connected to the first end of the resistor module, wherein the first end of the resistor module is the first end of the first-end resistor in the resistor module, and the third end of the first field effect transistor is connected to the first potential end;

[0012] The second end of the resistance module is connected to the second potential end, wherein the second end of the resistance module is the second end of the terminal resistor in the resistance module.

[0013] Furthermore, the channel calibration selection module includes: a multiplexing chip;

[0014] The first input end of the multiplexing chip is respectively connected to the first ends of multiple preset resistors in the resistance module, the second input end of the multiplexing chip is connected to the digital controller, and the output end of the multiplexing chip is connected to the corresponding channel current generating module.

[0015] Furthermore, the first field effect transistor is any one of the following: a PMOS transistor and an NMOS transistor;

[0016] When the first field effect transistor is a PMOS transistor, the first potential terminal is a power supply voltage, and the second potential terminal is a reference ground;

[0017] When the first field effect transistor is an NMOS transistor, the first potential terminal is a reference ground, and the second potential terminal is a power supply voltage.

[0018] In a second aspect, an embodiment of the present invention further provides an LED driver chip, comprising: a channel current calibration circuit of the LED driver chip according to any one of the first aspects above, further comprising: a reference voltage generation module and a plurality of channel current generation modules;

[0019] A first end of the reference voltage generating module is connected to a first input end of the channel current calibration circuit, a second end of the reference voltage generating module is connected to a first output end of a digital controller of an LED display device, and a third end of the reference voltage generating module is connected to first ends of a plurality of the channel current generating modules;

[0020] The plurality of second input terminals of the channel current calibration circuit are correspondingly connected to the plurality of second output terminals of the digital controller, and the plurality of output terminals of the channel current calibration circuit are correspondingly connected to the second terminal of each of the channel current generating modules;

[0021] The third end of each of the channel current generating modules is respectively connected to the plurality of third output ends of the digital controller, and the fourth end of each of the channel current generating modules is respectively connected to the LED display panel of the LED display device;

[0022] The reference voltage generating module is configured to generate a first reference voltage for the channel current calibration circuit, and to generate a second reference voltage for the channel current generating module according to a second control signal of the digital controller;

[0023] The channel current calibration circuit is configured to generate a target calibration voltage corresponding to each of the channel current generating modules according to the first reference voltage and the first control signal of the digital controller;

[0024] The channel current generating module is configured to generate a desired current for driving the LED display panel according to the second reference voltage, the target calibration voltage, and a third control signal of the digital controller.

[0025] Furthermore, the reference voltage generating module includes: a reference voltage generator, a reference current generator, a second operational amplifier and a channel gate voltage generator;

[0026] The first end of the reference voltage generator is connected to the reference current generator and the first end of the channel current calibration circuit respectively, and the second end of the reference voltage generator is connected to the negative input end of the second operational amplifier;

[0027] The positive input terminal of the second operational amplifier is connected to the output terminal of the second operational amplifier, and the output terminal of the second operational amplifier is also connected to the first terminal of the channel gate voltage generator;

[0028] The second end of the channel gate voltage generator is connected to the first end of the digital controller, and the third end of the channel gate voltage generator is connected to the first ends of the plurality of channel current generating modules.

[0029] Furthermore, the channel current generating module includes: a switch unit, a third operational amplifier and a second field effect transistor, wherein the switch unit includes: a plurality of PMOS transistors connected to a common cathode, or a plurality of NMOS transistors connected to a common anode;

[0030] The first end of the switch unit is connected to the reference voltage generating module, the second end of the switch unit is connected to the negative input end of the third operational amplifier, and the third end of the switch unit is connected to the third potential end;

[0031] The positive input terminal of the third operational amplifier is correspondingly connected to the output terminal of the channel current calibration circuit, the output terminal of the third operational amplifier is connected to the first terminal of the second field effect transistor, and the signal input terminal of the third operational amplifier is correspondingly connected to the third output terminal of the digital controller;

[0032] The second end of the second field effect transistor is connected to the second end of the switch unit, and the third end of the second field effect transistor is connected to the LED display panel of the LED display device.

[0033] Furthermore, the switch unit includes: when a plurality of PMOS tubes are connected with a common anode, the third potential terminal is a power supply voltage;

[0034] or,

[0035] When the switch unit includes a plurality of NMOS tubes connected with a common cathode, the third potential end is a reference ground.

[0036] In a third aspect, an embodiment of the present invention further provides an LED display device, comprising: the LED driver chip described in any one of the second aspects above, and further comprising: a digital controller and an LED display panel.

[0037] Furthermore, the LED display panel includes: a plurality of LED elements;

[0038] The plurality of LED elements are connected with a common anode or a common cathode, wherein the LED elements include any one of the following: conventional LED elements, quantum dot LED elements, perovskite LED elements, Mirco-LED elements and Mini-LED elements.

[0039] In an embodiment of the present invention, a channel current calibration circuit for an LED driver chip is provided, comprising: a calibration voltage generating module and a plurality of channel calibration selection modules; a first end of the calibration voltage generating module is connected to a reference voltage generating module of the LED driver chip, a second end of the calibration voltage generating module is connected to the first ends of the plurality of channel calibration selection modules, a second end of each channel calibration selection module is respectively connected to a digital controller of an LED display device, and a third end of each channel calibration selection module is respectively connected to a channel current generating module of the LED driver chip; the calibration voltage generating module is configured to receive a first reference voltage generated by the reference voltage generating module, and to adjust the first reference voltage according to a preset voltage difference to obtain a plurality of calibration voltages, wherein the voltage difference between adjacent calibration voltages is the preset voltage difference; and the channel calibration selection module is configured to receive the plurality of calibration voltages, and to select a target calibration voltage from the plurality of calibration voltages according to a first control signal of the digital controller, so as to calibrate the output current of the channel current generating module to a desired current value through the target calibration voltage. From the above description, it can be seen that the channel current calibration circuit of the LED driver chip of the present invention, when the reference voltage generating module provides the same reference voltage, the calibration voltage generating module can adjust the reference voltage to multiple calibration voltages according to the preset voltage difference, and use the channel calibration selection module to select the corresponding target calibration voltage for the corresponding channel current generating module, thereby calibrating the output current of each channel current generating module to the expected current value. At this time, even if there are parameter differences between the components of different channel current generating modules due to the manufacturing process, or there are input voltage errors (V in The channel current calibration circuit of the above-mentioned LED driver chip can adjust the channel current output by each channel current generating module to the expected value, thereby alleviating the technical problem of inconsistent output currents between different channel current generating circuits. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0041] Figure 1 A structural block diagram of a channel current calibration circuit for an LED driver chip provided by an embodiment of the present invention;

[0042] Figure 2 A schematic diagram of a first circuit structure of a calibration voltage generating module provided by an embodiment of the present invention;

[0043] Figure 3 A schematic diagram of a second circuit structure of a calibration voltage generating module provided by an embodiment of the present invention;

[0044] Figure 4 A third circuit structure diagram of a calibration voltage generating module provided by an embodiment of the present invention;

[0045] Figure 5 A schematic diagram of the circuit structure of a channel calibration selection module provided in an embodiment of the present invention;

[0046] Figure 6 A circuit structure block diagram of an LED driver chip provided by an embodiment of the present invention;

[0047] Figure 7 A schematic diagram of a first circuit structure of a reference voltage generating module provided by an embodiment of the present invention;

[0048] Figure 8 A schematic diagram of a second circuit structure of a reference voltage generating module provided by an embodiment of the present invention;

[0049] Figure 9 A schematic diagram of a first circuit structure of a channel current generating module provided by an embodiment of the present invention;

[0050] Figure 10 A schematic diagram of a second circuit structure of a channel current generating module provided by an embodiment of the present invention;

[0051] Figure 11 A third circuit structure diagram of a channel current generating module provided by an embodiment of the present invention;

[0052] Figure 12 A schematic diagram of a first circuit structure of an LED driver chip provided by an embodiment of the present invention;

[0053] Figure 13 A schematic diagram of a second circuit structure of an LED driver chip provided by an embodiment of the present invention;

[0054] Figure 14 This is a circuit structure block diagram of an LED display device provided by an embodiment of the present invention.

[0055] Icons: 11-LED driver chip; 12-digital controller; 13-LED display panel; 111-reference voltage generation module; 112-channel current calibration circuit; 113-channel current generation module; 1111-reference voltage generator; 1112-reference current generator; 1113-channel gate voltage generator; 1121-calibration voltage generation module; 1122-channel calibration selection module; 11211-resistance module; 1131-switch unit. DETAILED DESCRIPTION

[0056] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0057] To facilitate understanding of this embodiment, a channel current calibration circuit of an LED driver chip disclosed in an embodiment of the present invention is first introduced in detail.

[0058] Example 1:

[0059] Figure 1 FIG. 1 is a structural block diagram of a channel current calibration circuit of an LED driver chip according to an embodiment of the present invention. Figure 1 As shown, the circuit includes: a calibration voltage generating module 1121 and a plurality of channel calibration selecting modules 1122;

[0060] The first end of the calibration voltage generation module 1121 is connected to the reference voltage generation module 111 of the LED driver chip 11, the second end of the calibration voltage generation module 1121 is connected to the first end of multiple channel calibration selection modules 1122, the second end of each channel calibration selection module 1122 is respectively connected to the digital controller 12 of the LED display device, and the third end of each channel calibration selection module 1122 is respectively connected to a channel current generation module 113 of the LED driver chip 11;

[0061] The calibration voltage generating module 1121 is configured to receive the first reference voltage generated by the reference voltage generating module 111 and adjust the first reference voltage according to a preset voltage difference to obtain a plurality of calibration voltages, wherein the voltage difference between adjacent calibration voltages is the preset voltage difference;

[0062] The channel calibration selection module 1122 is configured to receive a plurality of calibration voltages and select a target calibration voltage from the plurality of calibration voltages according to a first control signal of the digital controller 12 , so as to calibrate the output current of the channel current generation module 113 to a desired current value through the target calibration voltage.

[0063] In the embodiments of the present invention, unless otherwise specified, for a device connected at the left and right ends, the first end refers to the left end of the device, and the second end refers to the right end of the device; for a device connected at the top and bottom ends, the first end refers to the upper end of the device, and the second end refers to the lower end of the device.

[0064] Specifically, the channel current calibration circuit of the LED driver chip of this embodiment includes: a calibration voltage generating module 1121 and a plurality of channel calibration selection modules 1122. Figure 1 As shown, the first end of the calibration voltage generating module 1121 is connected to the reference voltage generating module 111 of the LED driver chip, thereby receiving the first reference voltage VC output by the reference voltage generating module 111. IN , and according to the first reference voltage VC IN The voltage difference between adjacent calibration voltages is adjusted in sequence according to the preset voltage difference, thereby obtaining the adjusted multiple calibration voltages, wherein the voltage difference between the adjusted adjacent calibration voltages is the preset voltage difference. The second end of the calibration voltage generating module 1121 is connected to the first end of the multiple channel calibration selection modules 1122, thereby transmitting the adjusted multiple calibration voltages to the subsequent multiple channel calibration selection modules 1122, so that each channel calibration selection module 1122 can be controlled according to the first control signal TRIM of the digital controller 12.<Q+P:0> Select the target calibration voltage V that meets its requirements from multiple calibration voltages REF In specific implementation, the second end of each channel calibration selection module 1122 is connected to a channel current generating module 113 of the LED driver chip 11, thereby sending the first control signal TRIM<Q+P:0> Select the target calibration voltage V REF To the channel current generating module 113 connected to it. Then, the channel current generating module 113 generates the target calibration voltage V REF Calibrate the output current to reach the desired current value.

[0065] In an embodiment of the present invention, a channel current calibration circuit for an LED driver chip is provided, comprising: a calibration voltage generating module and a plurality of channel calibration selection modules; a first end of the calibration voltage generating module is connected to a reference voltage generating module of the LED driver chip, a second end of the calibration voltage generating module is connected to the first ends of the plurality of channel calibration selection modules, a second end of each channel calibration selection module is respectively connected to a digital controller of an LED display device, and a third end of each channel calibration selection module is respectively connected to a channel current generating module of the LED driver chip; the calibration voltage generating module is configured to receive a first reference voltage generated by the reference voltage generating module, and to adjust the first reference voltage according to a preset voltage difference to obtain a plurality of calibration voltages, wherein the voltage difference between adjacent calibration voltages is the preset voltage difference; and the channel calibration selection module is configured to receive the plurality of calibration voltages, and to select a target calibration voltage from the plurality of calibration voltages according to a first control signal of the digital controller, so as to calibrate the output current of the channel current generating module to a desired current value through the target calibration voltage. From the above description, it can be seen that the channel current calibration circuit of the LED driver chip of the present invention, when the reference voltage generating module provides the same reference voltage, the calibration voltage generating module can adjust the reference voltage to multiple calibration voltages according to the preset voltage difference, and use the channel calibration selection module to select the corresponding target calibration voltage for the corresponding channel current generating module, thereby calibrating the output current of each channel current generating module to the expected current value. At this time, even if there are parameter differences between the components of different channel current generating modules due to the manufacturing process, or there are input voltage errors (V in The channel current calibration circuit of the above-mentioned LED driver chip can adjust the channel current output by each channel current generating module to the expected value, thereby alleviating the technical problem of inconsistent output currents between different channel current generating circuits.

[0066] The above content provides an overall description of the structural block diagram of the channel current calibration circuit of the LED driver chip. The following is a detailed introduction to the specific circuit structure and working principle of the channel current calibration circuit of the LED driver chip.

[0067] In an alternative embodiment of the present invention, reference Figure 2 The calibration voltage generating module 1121 includes: a first operational amplifier AMP1, a first field effect transistor Q1 and a resistor module 11211 composed of a plurality of resistors connected in series;

[0068] The negative input terminal of the first operational amplifier AMP1 is connected to the reference voltage generating module 111, the positive input terminal of the first operational amplifier AMP1 is connected to one end of any resistor in the resistance module 11211, and the output terminal of the first operational amplifier AMP1 is connected to the first end of the first field effect transistor Q1;

[0069] The second end of the first field effect transistor Q1 is connected to the first end of the resistor module 11211, wherein the first end of the resistor module 11211 is the first end of the first-end resistor in the resistor module 11211, and the third end of the first field effect transistor Q1 is connected to the first potential end;

[0070] The second end of the resistance module 11211 is connected to the second potential end, wherein the second end of the resistance module 11211 is the second end of the terminal resistor in the resistance module.

[0071] In addition, the first field effect transistor Q1 is any one of the following: a PMOS transistor and an NMOS transistor;

[0072] When the first field effect transistor Q1 is a PMOS transistor, the first potential terminal is the power supply voltage, and the second potential terminal is the reference ground;

[0073] When the first field effect transistor Q1 is an NMOS transistor, the first potential terminal is a reference ground, and the second potential terminal is a power supply voltage.

[0074] Specifically, the calibration voltage generating module 1121 of this embodiment includes: a first operational amplifier AMP1, a first field effect transistor Q1 and a resistor module 11211 composed of a plurality of resistors connected in series. The specific circuit topology is as follows: Figure 2 As shown, the negative input terminal of the first operational amplifier AMP1 is connected to the reference voltage generating module 111, and is used to receive the reference voltage VC generated by the reference voltage generating module 111. IN The output terminal of the first operational amplifier AMP1 is connected to the gate of the first field effect transistor Q1, and the positive input terminal is connected to one end of any resistor in the resistor module, wherein the resistor module 11211 includes Q+P+M+1 resistors. Figure 3 When the first field effect transistor Q1 is a PMOS tube, the drain of the PMOS is connected to the first end of the resistor module (i.e., the first end of the first-end resistor R0 in the resistor module 11211), and the source of the PMOS is connected to the power supply voltage V DD Connect the second end of the resistor module 11211 (ie, the terminal resistor R Q+P+M The second end of the reference Figure 4 When the first field effect transistor Q1 is an NMOS transistor, the drain of the NMOS is connected to the first end of the resistor module 11211 (i.e., the first end of the first resistor R0 in the resistor module 11211), and the source of the NMOS is grounded. The second end of the resistor module 11211 (i.e., the terminal resistor R Q+P+M The second end) is connected to the power supply voltage V DD connect.

[0075] In specific implementation, in order to realize the reference voltage VC generated by the reference voltage generating module 111IN According to the preset voltage difference, multiple calibration voltages are adjusted. In this embodiment, according to the adjustment requirements of the subsequently connected channel current generating module, Q+P+1 preset resistors are selected from the Q+P+M+1 resistors included in the resistor module 11211, and a common connection point is provided at the port of each preset resistor. That is, the resistor module 11211 provides a total of Q+P+1 common connections. Q+P+1 calibration voltages (VC<Q+P:0> ), wherein the voltage difference between adjacent calibration voltages is the voltage divided by the preset resistor between the corresponding two common points.

[0076] In an alternative embodiment of the present invention, reference Figure 5 , the channel calibration selection module 1122 includes: a multiplexing chip;

[0077] The first input end of the multiplexing chip is respectively connected to the first ends of multiple preset resistors in the resistance module 11211, the second input end of the multiplexing chip is connected to the digital controller 12, and the output end of the multiplexing chip is connected to its corresponding channel current generating module 113.

[0078] Specifically, each channel calibration selection module 1122 includes a multiplexing chip, wherein the multiplexing chip MUX has Q+P+1 first input terminals, and each first input terminal is respectively connected to Q+P+1 common points provided by the preset resistors in the aforementioned resistance module 11211, thereby receiving Q+P+1 calibration voltages (VC) generated by the calibration voltage generation module 1121.<Q+P:0> ). Secondly, the second input end of the multiplexing chip MUX of each channel calibration selection module 1122 is connected to the digital controller 12 respectively, and the first control signal TRIM corresponding to the first control signal TRIM is output by the digital controller 12.<Q+P:0> , select the target calibration voltage V REF Then, the output terminal transmits the current to the corresponding channel current generating module 113, so that the channel current generating module 113 can adjust the current according to the target calibration voltage V REF Output channel current that meets the expected voltage value.

[0079] Example 2:

[0080] A LED driver chip, reference Figure 6 , comprising: a channel current calibration circuit 112 of the LED driver chip of any one of the above-mentioned embodiments 1, further comprising: a reference voltage generating module 111 and a plurality of channel current generating modules 113;

[0081] A first end of the reference voltage generating module 111 is connected to a first input end of the channel current calibration circuit 112, a second end of the reference voltage generating module 111 is connected to a first output end of the digital controller 12 of the LED display device, and a third end of the reference voltage generating module 111 is connected to first ends of the plurality of channel current generating modules 113;

[0082] The multiple second input terminals of the channel current calibration circuit 112 are correspondingly connected to the multiple second output terminals of the digital controller 12 , and the multiple output terminals of the channel current calibration circuit 112 are correspondingly connected to the second terminal of each channel current generating module 113 ;

[0083] The third end of each channel current generating module 113 is respectively connected to the plurality of third output ends of the digital controller 12, and the fourth end of each channel current generating module 113 is respectively connected to the LED display panel of the LED display device;

[0084] A reference voltage generating module 111 is configured to generate a first reference voltage for the channel current calibration circuit 112 and to generate a second reference voltage for the channel current generating module 113 according to a second control signal of the digital controller 12;

[0085] a channel current calibration circuit 112 for generating a target calibration voltage corresponding to each channel current generating module 113 according to the first reference voltage and the first control signal of the digital controller 12;

[0086] The channel current generating module 113 is configured to generate a desired current for driving the LED display panel according to the second reference voltage, the target calibration voltage, and the third control signal of the digital controller 12 .

[0087] Specifically, the LED driver chip 11 of this embodiment includes: a reference voltage generating module 111, a channel current calibration circuit 112 and a plurality of channel current generating modules 113. Figure 6 As shown, first, the first terminal of the reference voltage generating module 111 is connected to the first input terminal of the channel current calibration circuit 112, so as to realize the first reference voltage VC generated by the reference voltage generating module 111. IN The calibration voltage generating module 1121 in the channel current calibration circuit 112 receives the first reference voltage VC IN After adjusting to a plurality of calibration voltages, the channel calibration selection module 1122 corresponding to each channel current generating module 113 is used to select the channel current generating module 113 according to the first control signal TRIM corresponding to each channel calibration selection module 1122.<Q+P:0> Generates a target calibration voltage V corresponding to each channel current generating module 113 REFFinally, the output terminal of each channel calibration selection module 1122 is correspondingly transmitted to each channel current generation module 113 .

[0088] Secondly, the reference voltage generating module 111 is also connected to the digital controller 12 and the multiple channel current generating modules 113. In specific implementation, the reference voltage generating module 111 is connected to the digital controller 12 by the second control signal SEL <s-1:0>The second reference voltage V generated by GATE <s-1:0>, and correspondingly transmitted to each channel current generating module 113, wherein S represents the number of field effect transistors in the switch unit 1131 of a single channel current generating module 113 connected subsequently. Finally, each channel current generating module 113 is calibrated according to its corresponding target voltage V REF , the second reference voltage V GATE <s-1:0>and the third control signal PWM of the digital controller <n-1:0>Generate a desired current that can drive a subsequent LED display panel, where N represents the number of channel current generating modules 113 .

[0089] In an alternative embodiment of the present invention, reference Figure 7 The reference voltage generating module 111 includes: a reference voltage generator 1111, a reference current generator 1112, a second operational amplifier AMP2 and a channel gate voltage generator 1113;

[0090] A first terminal of the reference voltage generator 1111 is connected to the first terminal of the reference current generator 1112 and the channel current calibration circuit 112 respectively, and a second terminal of the reference voltage generator 1111 is connected to the negative input terminal of the second operational amplifier AMP2;

[0091] The positive input terminal of the second operational amplifier AMP2 is connected to the output terminal of the second operational amplifier AMP2, and the output terminal of the second operational amplifier AMP2 is also connected to the first terminal of the channel gate voltage generator 1113;

[0092] A second terminal of the channel gate voltage generator 1113 is connected to a first terminal of the digital controller 12 , and a third terminal of the channel gate voltage generator 1113 is connected to first terminals of the plurality of channel current generating modules 113 .

[0093] Specifically, the reference voltage generating module 111 includes: a reference voltage generator 1111, a reference current generator 1112, a second operational amplifier AMP2 and a channel gate voltage generator 1113, wherein the reference voltage generator 1111 also includes a knee voltage generating module, a fourth operational amplifier APM4 and a reference MOS transistor Q3. The specific circuit topology is as follows: Figure 8 shown.

[0094] In a specific implementation, the reference voltage generator 1111 is connected to the reference current generator 1112 and the channel current calibration circuit 112 respectively, so that the reference voltage generator 1111 and the reference current generator 1112 jointly provide the first reference voltage VC for the channel current calibration circuit 112. IN At this time, the gate terminal of the reference MOS transistor Q3 inside the reference voltage generator 1111 will generate a reference gate voltage V GATE , and sends the reference gate voltage V through the second operational amplifier AMP2 GATE To the channel gate voltage generator 1113, so that the channel gate voltage generator 1113 is controlled by the second control signal SEL <s-1:0>Under the action of , a second reference voltage V corresponding to the subsequent multiple channel current generating modules 113 is generated. GATE <s-1:0>.

[0095] In an alternative embodiment of the present invention, reference Figure 9 The channel current generating module 113 includes: a switch unit 1131, a third operational amplifier APM3 and a second field effect transistor Q2, the switch unit 1131 includes: a plurality of PMOS transistors connected to a common cathode, or a plurality of NMOS transistors connected to a common anode;

[0096] A first end of the switch unit 1131 is connected to the reference voltage generating module 111 , a second end of the switch unit 1131 is connected to the negative input end of the third operational amplifier APM3 , and a third end of the switch unit 1131 is connected to the third potential end;

[0097] The positive input terminal of the third operational amplifier APM3 is connected to the output terminal of the channel current calibration circuit 112, the output terminal of the third operational amplifier APM3 is connected to the first terminal of the second field effect transistor Q2, and the signal input terminal of the third operational amplifier APM3 is connected to the third output terminal of the digital controller 12.

[0098] The second end of the second field effect transistor Q2 is connected to the second end of the switch unit 1131 , and the third end of the second field effect transistor Q2 is connected to the LED display panel 13 of the LED display device.

[0099] In addition, the switch unit 1131 includes: when a plurality of PMOS tubes are connected with a common anode, the third potential terminal is the power supply voltage;

[0100] or,

[0101] The switch unit 1131 includes: a plurality of NMOS transistors connected with a common cathode, and the third potential terminal is a reference ground.

[0102] Specifically, the channel current generating module 113 includes: a switch unit 1131, a third operational amplifier APM3 and a second field effect transistor Q2, wherein the switch unit 1131 includes: S PMOS transistors connected to a common cathode, or S NMOS transistors connected to a common anode. The specific circuit topology inside the switch unit is as follows: Figure 10 and Figure 11 shown.

[0103] In specific implementation, taking a single channel current generating module 113 as an example, the second reference voltage V generated by the reference voltage generating module 111 is GATE <s-1:0>The voltage is transmitted to the switch unit 1131 of the channel current generating module 113, so that the S MOS transistors in the switch unit 1131 can receive the corresponding gate voltage V GATE <0> ,……,V GATE <s-1>, thereby realizing the conduction of the MOS tube. When the switch unit 1131 operates normally, the switch unit 1131 will generate a voltage V CES And transmit the terminal voltage V CES At this time, the target calibration voltage V transmitted by the channel current calibration circuit 112 and received by the positive input terminal of the third operational amplifier APM3 is combined with the negative input terminal of the third operational amplifier APM3. REF And the PWM signal output by the digital controller 12 corresponding to the channel current generating module 113 <n-1:0>The output terminal of the third operational amplifier APM3 generates an output voltage to the second field effect transistor Q2. Finally, the second field effect transistor Q2 generates an output voltage to the second field effect transistor Q2 when the output voltage provided by the third operational amplifier APM3 and the terminal voltage V provided by the switch unit 1131 are both equal. CES Under the action of , a channel current that meets the expected value is generated and sent to the subsequently connected LED display panel, thereby driving the LED elements in the corresponding area of the LED display panel to emit light.

[0104] It is worth noting that, in the above example, a single channel current generating module 113 is used. In this embodiment, when N channel current generating modules 113 work together, due to the presence of the channel current calibration circuit 112 in the LED driver chip of this embodiment, even if the S MOS transistors in each channel current generating module 113 have parameter differences due to the manufacturing process, or there is an input voltage error (V in offset), the reference voltage generating module 111 provides the same first reference voltage VC IN and the second reference voltage V GATE <s-1:0>In this case, the multiple channel current generating modules 113 will output channel currents of the same magnitude, that is, they all meet the expected current value. Finally, when the field effect transistors inside the LED driver chip of this embodiment are PMOS or NMOS, the corresponding overall circuit structure diagrams are as follows: Figure 12 and Figure 13 shown.

[0105] Example 3:

[0106] An LED display device, referring to Figure 14 , including: the LED driver chip 11 described in any one of the above-mentioned embodiments 2, and also including: a digital controller 12 and an LED display panel 13.

[0107] Specifically, the LED display device of this embodiment includes: an LED driver chip 11, a digital controller 12, and an LED display panel 13. The input end of the LED driver chip 11 is connected to the digital controller 12, and the output end of the LED driver chip 11 is connected to the LED display panel 13, so that the LED driver chip 11 drives the LED display panel 13 to emit light under the control of the digital controller 12.

[0108] In an optional embodiment of the present invention, the LED display panel 13 includes: a plurality of LED elements;

[0109] Multiple LED elements are connected with a common anode or a common cathode, wherein the LED elements include any one of the following: conventional LED elements, quantum dot LED elements, perovskite LED elements, Mirco-LED elements and Mini-LED elements.

[0110] The computer program product of the LED display device provided in the embodiment of the present invention includes a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the method described in the previous method embodiment. The specific implementation can be found in the method embodiment and will not be repeated here.

[0111] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described systems and devices can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0112] In the embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interface, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0113] For another example, the flowcharts and block diagrams in the accompanying drawings show the possible architectures, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of code, and the module, program segment or a part of code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of the boxes in the block diagram and / or flowchart, can be implemented with a dedicated hardware-based system that performs the specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0114] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0115] In addition, each functional unit in the embodiments provided in the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0116] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling an electronic device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0117] It should be noted that similar reference numerals and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined or explained in subsequent figures. In addition, the terms "first," "second," "third," etc. are used only to distinguish and describe, and should not be understood to indicate or imply relative importance. Finally, it should be noted that the above-described embodiments are merely specific implementation methods of this application, used to illustrate the technical solutions of this application, not to limit them. The scope of protection of this application is not limited thereto. Although this application has been described in detail with reference to the above-described embodiments, a person of ordinary skill in the art should understand that any person skilled in the art can modify or easily conceive of variations to the technical solutions described in the above-described embodiments, or substitute equivalent features for some of the technical features thereof, within the technical scope disclosed in this application. Such modifications, variations, or substitutions do not deviate from the essence of the corresponding technical solutions within the scope of the technical solutions of the embodiments of this application and are all encompassed by the scope of protection of this application. Therefore, the scope of protection of this application shall be based on the scope of protection of the claims.

Claims

1. A channel current calibration circuit for an LED driver chip, characterized in that: include: Calibration voltage generation module and multiple channel calibration selection modules; The first end of the calibration voltage generating module is connected to the reference voltage generating module of the LED driver chip, the second end of the calibration voltage generating module is connected to the first ends of the plurality of channel calibration selection modules, the second end of each of the channel calibration selection modules is respectively connected to the digital controller of the LED display device, and the third end of each of the channel calibration selection modules is respectively connected to a channel current generating module of the LED driver chip; The calibration voltage generating module is configured to receive the first reference voltage generated by the reference voltage generating module and adjust the first reference voltage according to a preset voltage difference to obtain a plurality of calibration voltages, wherein the voltage difference between adjacent calibration voltages is the preset voltage difference; The channel calibration selection module is configured to receive the plurality of calibration voltages and select a target calibration voltage from the plurality of calibration voltages according to a first control signal of the digital controller, so as to calibrate the output current of the channel current generating module to a desired current value through the target calibration voltage; The calibration voltage generation module includes: a resistance module consisting of a first operational amplifier, a first field-effect transistor, and a plurality of resistors connected in series; a negative input terminal of the first operational amplifier is connected to the reference voltage generation module, a positive input terminal of the first operational amplifier is connected to one end of any resistor in the resistance module, and an output terminal of the first operational amplifier is connected to the first end of the first field-effect transistor; a second end of the first field-effect transistor is connected to the first end of the resistance module, wherein the first end of the resistance module is the first end of the head resistor in the resistance module, and the third end of the first field-effect transistor is connected to the first potential terminal; a second end of the resistance module is connected to the second potential terminal, wherein the second end of the resistance module is the second end of the terminal resistor in the resistance module; The channel calibration selection module includes: a multiplexing chip; a first input end of the multiplexing chip is respectively connected to the first ends of multiple preset resistors in the resistance module, a second input end of the multiplexing chip is connected to the digital controller, and an output end of the multiplexing chip is connected to the corresponding channel current generating module; The first field effect transistor is any one of the following: a PMOS transistor and an NMOS transistor; when the first field effect transistor is a PMOS transistor, the first potential end is a power supply voltage, and the second potential end is a reference ground; when the first field effect transistor is an NMOS transistor, the first potential end is a reference ground, and the second potential end is a power supply voltage.

2. An LED driver chip, characterized in that: include: The channel current calibration circuit of the LED driver chip according to claim 1 further comprises: a reference voltage generating module and a plurality of channel current generating modules; A first end of the reference voltage generating module is connected to a first input end of the channel current calibration circuit, a second end of the reference voltage generating module is connected to a first output end of a digital controller of an LED display device, and a third end of the reference voltage generating module is connected to first ends of a plurality of the channel current generating modules; The plurality of second input terminals of the channel current calibration circuit are correspondingly connected to the plurality of second output terminals of the digital controller, and the plurality of output terminals of the channel current calibration circuit are correspondingly connected to the second terminal of each of the channel current generating modules; The third end of each of the channel current generating modules is respectively connected to the plurality of third output ends of the digital controller, and the fourth end of each of the channel current generating modules is respectively connected to the LED display panel of the LED display device; The reference voltage generating module is configured to generate a first reference voltage for the channel current calibration circuit, and to generate a second reference voltage for the channel current generating module according to a second control signal of the digital controller; The channel current calibration circuit is configured to generate a target calibration voltage corresponding to each of the channel current generating modules according to the first reference voltage and the first control signal of the digital controller; The channel current generating module is configured to generate a desired current for driving the LED display panel according to the second reference voltage, the target calibration voltage, and a third control signal of the digital controller.

3. The LED driver chip according to claim 2, characterized in that: The reference voltage generating module includes: a reference voltage generator, a reference current generator, a second operational amplifier and a channel gate voltage generator; The first end of the reference voltage generator is connected to the reference current generator and the first end of the channel current calibration circuit respectively, and the second end of the reference voltage generator is connected to the negative input end of the second operational amplifier; The positive input terminal of the second operational amplifier is connected to the output terminal of the second operational amplifier, and the output terminal of the second operational amplifier is also connected to the first terminal of the channel gate voltage generator; The second end of the channel gate voltage generator is connected to the first end of the digital controller, and the third end of the channel gate voltage generator is connected to the first ends of the plurality of channel current generating modules.

4. The LED driver chip according to claim 2, characterized in that: The channel current generating module includes: a switch unit, a third operational amplifier and a second field effect transistor, wherein the switch unit includes: a plurality of PMOS transistors connected to a common cathode, or a plurality of NMOS transistors connected to a common anode; The first end of the switch unit is connected to the reference voltage generating module, the second end of the switch unit is connected to the negative input end of the third operational amplifier, and the third end of the switch unit is connected to the third potential end; The positive input terminal of the third operational amplifier is correspondingly connected to the output terminal of the channel current calibration circuit, the output terminal of the third operational amplifier is connected to the first terminal of the second field effect transistor, and the signal input terminal of the third operational amplifier is correspondingly connected to the third output terminal of the digital controller; The second end of the second field effect transistor is connected to the second end of the switch unit, and the third end of the second field effect transistor is connected to the LED display panel of the LED display device.

5. The LED driver chip according to claim 4, characterized in that: The switch unit includes: when a plurality of PMOS tubes are connected to a common anode, the third potential end is a power supply voltage; or, When the switch unit includes a plurality of NMOS tubes connected with a common cathode, the third potential end is a reference ground.

6. An LED display device, characterized in that: include: The LED driver chip according to any one of claims 2 to 5 further comprises: a digital controller and an LED display panel.

7. The LED display device according to claim 6, characterized in that: The LED display panel includes: a plurality of LED elements; The plurality of LED elements are connected with a common anode or a common cathode, wherein the LED elements include any one of the following: conventional LED elements, quantum dot LED elements, perovskite LED elements, Mirco-LED elements and Mini-LED elements.

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