CN117238242B

CN117238242B - Implementation method of Micro LED current type driving circuit for improving mirror image precision of current mirror

Info

Publication number: CN117238242B
Application number: CN202311515391.6A
Authority: CN
Inventors: 李科举; 麻胜恒; 朱警怡
Original assignee: Zhongke Shenzhen Wireless Semiconductor Co ltd
Current assignee: Zhongke Shenzhen Wireless Semiconductor Co ltd
Priority date: 2023-11-15
Filing date: 2023-11-15
Publication date: 2024-03-22
Anticipated expiration: 2043-11-15
Also published as: CN117238242A

Abstract

The invention discloses a realization method of a Micro LED current type driving circuit for improving mirror image precision of a current mirror, wherein the driving circuit consists of a source electrode driving circuit and a pixel point current type driving circuit; the source driving circuit consists of an operational amplifier OP and a resistor Rr1, a resistor Rr2 and a transistor PM1, wherein one end of the resistor Rr1 is connected with two input ends of the operational amplifier OP, and the other end of the resistor Rr2 is grounded, and the drain electrode of the transistor PM is connected with an inverting input end Vn of the operational amplifier OP; the output end of the operational amplifier OP is connected with the pixel point current type driving circuit; the gate of the transistor PM1 is connected to the control voltage Vc, and the source of the transistor PM1 is connected to the pixel current type driving circuit. The driving circuit has high response speed. And the power supply voltage ELVDD can be appropriately reduced. Therefore, the invention can reduce the driving power consumption and ensure the current output precision.

Description

Implementation method of Micro LED current type driving circuit for improving mirror image precision of current mirror

Technical Field

The invention belongs to the technical field of integrated circuits, and particularly relates to a realization method of a Micro LED current type driving circuit for improving mirror image precision of a current mirror.

Background

Micro LEDs are a kind of Micro-sized light emitting diode, and the size of the light emitting unit is smaller than 100um (50 um is defined by some enterprises) and is defined as Micro LEDs. Micro LEDs are a current-mode device, i.e. their current determines their light-emitting brightness. The micro LED has the characteristics of high luminous brightness, high luminous efficiency, high response speed and the like, and is the most ideal light-emitting device at present. The Micro LED direct display screen made of the Micro LED light-emitting units with extremely small sizes and self-luminous characteristics has the advantages of high brightness, high contrast, high resolution, long service life, low power consumption, wide color gamut and the like, and therefore becomes a main research direction of the current display technology.

Some prior art pixel circuits for OLED driving also employ current-driven methods, such as those described in applications 201210133100.2 and 2013102144664.3. However, these current driving methods are not practical because the gate capacitor is directly charged or discharged by the gradation current, and it is known that the gradation current is extremely small and the gate capacitor is charged or discharged at an extremely low speed at the time of low gradation. Second, in the existing current mirror driving scheme, the drain-source voltage Vds difference may affect the current mirror accuracy.

Disclosure of Invention

The invention aims to provide a Micro LED current type driving circuit for improving the mirror image precision of a current mirror and an implementation method thereof, which mainly solve the problem of low current mirror image precision in the existing current mirror driving scheme.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:

a Micro LED current type driving circuit for improving mirror image precision of a current mirror is composed of a source electrode driving circuit, a pixel point current type driving circuit and a precision improving module; the precision improvement module is used for enabling the drain-source voltage of a driving tube in the pixel point current type driving circuit to be the same in a current driving stage and a display stage.

Further, in the present invention, the source driving circuit is formed by an operational amplifier OP and a resistor Rr1 and a resistor Rr2, one end of which is connected to two input ends of the operational amplifier OP and the other end of which is grounded, and the output end and the inverting input end Vn of the operational amplifier OP are connected to the pixel point current type driving circuit; the non-inverting input terminal of the operational amplifier OP inputs the current Idata.

Further, in the present invention, the pixel point current type driving circuit includes a transistor TS1 and a transistor TS2 with gate electrodes connected to each other, a gate electrode connected to a source electrode of the transistor TS1, a drain electrode connected to the source electrode of the transistor TS2, a capacitor Cst connected between the gate electrode and the source electrode of the transistor DT1, a transistor TS3 with a source electrode connected to the drain electrode of the transistor DT1, a gate electrode connected to an enable signal EN, and an LED with a positive electrode connected to the drain electrode of the transistor TS3 and a negative electrode grounded; wherein, the drain electrode of the transistor TS1 is connected with the output end of the operational amplifier OP, and the drain electrode of the transistor TS2 is connected with the source electrode of the transistor PM1; the source of the transistor DT1 is connected to the power source ELVDD.

Further, in the present invention, the pixel point current type driving circuit includes a transistor TS1 and a transistor TS2 with gate electrodes connected to each other, a gate electrode connected to a source electrode of the transistor TS1, a drain electrode connected to a source electrode of the transistor TS2, a capacitor Cst connected between the gate electrode and the source electrode of the transistor DT2, a gate electrode connected to the source electrode of the transistor TS1, a source electrode connected to the source electrode of the transistor DT2, a source electrode connected to a drain electrode of the transistor DT1, a transistor TS3 with a gate electrode connected to an enable signal EN, and an LED with a positive electrode connected to the drain electrode of the transistor TS3 and a negative electrode grounded; wherein, the drain electrode of the transistor TS1 is connected with the output end of the operational amplifier OP, and the drain electrode of the transistor TS2 is connected with the source electrode of the transistor PM1; the source of the transistor DT1 and the source of the transistor DT2 are connected to a power source ELVD.

Further, in the present invention, the precision improving module is a transistor PM1; the drain of the transistor PM1 is connected to the inverting input Vn of the operational amplifier OP, the gate of the transistor PM1 is connected to the control voltage Vc, and the source of the transistor PM1 is connected to the drain of the transistor TS 2.

Further, in the present invention, the precision improving module is a transistor PM2 connected between the transistor DT1 and the transistor TS 3; wherein the drain of the transistor PM2 is connected to the source of the transistor DT 1; the source of the transistor PM2 is connected to the source of the transistor TS3, and the gate of the transistor PM2 is connected to the control voltage Vrb.

Further, in the present invention, the precision improving module is a transistor DT3 connected between a transistor DT1 and a transistor TS3 and a transistor DT4 connected between a transistor DT2 and a transistor TS 2; wherein the drain of the transistor DT3 is connected with the source of the transistor DT 1; the source of the transistor DT3 is connected to the source of the transistor TS3, and the drain of the transistor DT4 is connected to the source of the transistor DT 2; the source of the transistor DT4 is connected to the source of the transistor TS2, and the transistor DT4 is connected to the gate of the transistor DT3 and then connected to the control voltage Vrb.

The realization method of the Micro LED current type driving circuit for improving the mirror image precision of the current mirror comprises the steps that Wn signals are adopted to control a transistor TS1 and a transistor TS2 simultaneously, idata current is added to a resistor Rr1 to obtain a non-inverting input end Vp of a corresponding voltage input operational amplifier OP, meanwhile, when the transistor TS1 and the transistor TS2 are opened, a voltage Vg of a capacitor Cst drives the transistor DT1 to be opened, and output current Ifb flows back to an inverting input end Vn of the operational amplifier OP through the transistor TS2 through the transistor PM1; and the source voltage Vfb of the transistor PM1 is made equal to the anode voltage VLED of the Micro LED in the display stage;

the output voltage Vdrv of the operational amplifier OP controls the charge and discharge of the capacitor Cst through the transistor TS1, and the voltage Vg is adjusted, so that the output current Ifb of the transistor DT1 is adjusted until the voltage of the Ifb current applied to the resistor Rr2, namely the voltage of the inverting input end Vn is the same as the voltage of the non-inverting input end Vp of the operational amplifier OP; the output voltage Vdrv of the operational amplifier OP is stable, the voltage Vg of the transistor DT1 is stable, the transistor DT1 outputs a stable current Ifb, and the voltage of two input ends of the operational amplifier OP is the same to obtain idata×rr1=ifb×rr2, i.e., ifb=idata×rr1/Rr2; the Ifb current magnitude is precisely scaled to the Idata current;

the Ifb current is the output current of the transistor DT1, that is, the transistor DT1 as a driving tube can accurately output Idata current; or the gate-source voltages Vgs of the transistor DT1 and the transistor DT2 are the same; the output current of the transistor DT1 can accurately mirror the Ifb current output of the transistor DT 2; namely, the transistor DT1 as a driving tube can accurately output Idata current;

wherein the source-drain voltage drop Vds2 when the current Ifb flows through the transistor TS2 is equal to the source-drain voltage drop Vds3 when the driving current flows through the transistor TS 3; when vfb=vled, the drain-source voltages of the transistor DT1 are the same in the current driving stage and the display stage, so that the output current of the transistor DT1 is the same, and the current Ifb is equal to the Micro LED current.

The realization method of the Micro LED current type driving circuit for improving the mirror image precision of the current mirror comprises the steps that a Wn signal is adopted to simultaneously control a transistor TS1 and a transistor TS2, idata current is added to a resistor Rr1 to obtain a non-inverting input end Vp of a corresponding voltage input operational amplifier OP, meanwhile, when the transistor TS1 and the transistor TS2 are opened, a voltage Vg of a capacitor Cst drives the transistor DT1 to be opened, and output current Ifb flows back to an inverting input end Vn of the operational amplifier OP through the transistor TS 2;

the output voltage Vdrv of the operational amplifier OP controls the charge and discharge of the capacitor Cst through the transistor TS1, and the voltage Vg is adjusted, so that the output current Ifb of the transistor DT1 is adjusted until the voltage of the Ifb current applied to the resistor Rr2, namely the voltage of the inverting input end Vn is the same as the voltage of the non-inverting input end Vp of the operational amplifier OP; the output voltage Vdrv of the operational amplifier OP is stable, the voltage Vg of the transistor DT1 is stable, the transistor DT1 outputs a stable current Ifb, and the voltage of two input ends of the operational amplifier OP is the same to obtain idata×rr1=ifb×rr2, i.e., ifb=idata×rr1/Rr2; the Ifb current magnitude is precisely scaled to the Idata current; the Ifb current is the output current of the transistor DT1, that is, the transistor DT1 as a driving tube can accurately output Idata current;

the current flowing through the transistor PM2 in the current driving stage and the display stage are the same, so that the gate-source voltage of the transistor PM2 remains unchanged, the source-drain voltage Vds of the driving transistor in the current driving stage and the display stage remains unchanged, the transistor DT1 outputs a high-precision current, and the voltage Vrb is adjusted to adjust the drain voltage of the driving transistor DT 1.

The realization method of the Micro LED current type driving circuit for improving the mirror image precision of the current mirror comprises the steps that a Wn signal is adopted to simultaneously control a transistor TS1 and a transistor TS2, idata current is added to a resistor Rr1 to obtain a non-inverting input end Vp of a corresponding voltage input operational amplifier OP, meanwhile, when the transistor TS1 and the transistor TS2 are opened, a voltage Vg of a capacitor Cst drives the transistor DT2 to be opened, and output current Ifb flows back to an inverting input end Vn of the operational amplifier OP through the transistor TS 2;

the output voltage Vdrv of the operational amplifier OP controls the charge and discharge of the capacitor Cst through the transistor TS1, and the voltage Vg is adjusted, so that the output current Ifb of the transistor DT1 is adjusted until the voltage of the Ifb current applied to the resistor Rr2, namely the voltage of the inverting input end Vn is the same as the voltage of the non-inverting input end Vp of the operational amplifier OP; the output voltage Vdrv of the operational amplifier OP is stable, the voltage Vg of the transistor DT1 is stable, the transistor DT1 outputs a stable current Ifb, and the voltage of two input ends of the operational amplifier OP is the same to obtain idata×rr1=ifb×rr2, i.e., ifb=idata×rr1/Rr2; the Ifb current magnitude is precisely scaled to the Idata current; and the gate-source voltages Vgs of the transistor DT1 and the transistor DT2 are the same; the output current of the transistor DT1 can accurately mirror the Ifb current output of the transistor DT 2; namely, the transistor DT1 as a driving tube can accurately output Idata current;

where Vgs 4=vgs 3, vd2=vd1, and vds2=vds1, thereby improving the current mirror accuracy of the transistor DT2 and the transistor DT 1; vgs4 is the gate-source voltage of transistor DT4; vgs3 is the gate-source voltage of transistor DT 3; vd2 is the drain voltage of the transistor DT 2; vd1 is the drain voltage of the transistor DT 1; vds2 is the drain-source voltage of the transistor DT2, and Vds1 is the drain-source voltage of the transistor DT 1.

Drawings

Fig. 1 is a schematic circuit diagram of an embodiment 1 of the present invention.

Fig. 2 is a schematic circuit diagram of embodiment 2 of the present invention.

Fig. 3 is a schematic circuit diagram of embodiment 3 of the present invention.

Fig. 4 is a schematic circuit diagram of embodiment 4 of the present invention.

Fig. 5 is a control timing diagram of all embodiments of the present invention.

Detailed Description

The invention will be further illustrated by the following description and examples, which include but are not limited to the following examples.

The invention discloses a Micro LED current type driving circuit for improving mirror image precision of a current mirror, which consists of a source electrode driving circuit, a pixel point current type driving circuit and a precision improving module; the precision improvement module is used for enabling the drain-source voltage of a driving tube in the pixel point current type driving circuit to be the same in a current driving stage and a display stage.

The source driving circuit is composed of an operational amplifier OP and a resistor Rr1 and a resistor Rr2, one end of the resistor Rr1 and one end of the resistor Rr2 are respectively connected with two input ends of the operational amplifier OP, and the output end and the inverting input end Vn of the operational amplifier OP are connected with the pixel point current type driving circuit; the non-inverting input terminal of the operational amplifier OP inputs the current Idata.

Example 1

As shown in fig. 1, in this embodiment, the pixel point current type driving circuit includes a transistor TS1 and a transistor TS2 with gate electrodes connected to each other, a gate electrode connected to a source electrode of the transistor TS1, a drain electrode connected to the source electrode of the transistor TS2, a capacitor Cst connected between the gate electrode and the source electrode of the transistor DT1, a transistor TS3 with a source electrode connected to the drain electrode of the transistor DT1, a gate electrode connected to an enable signal EN, and an LED with a positive electrode connected to the drain electrode of the transistor TS3 and a negative electrode grounded; wherein, the drain electrode of the transistor TS1 is connected with the output end of the operational amplifier OP, and the drain electrode of the transistor TS2 is connected with the source electrode of the transistor PM1; the source of the transistor DT1 is connected to the power source ELVDD.

In this embodiment, the precision improving module is a transistor PM1; the drain of the transistor PM1 is connected to the inverting input Vn of the operational amplifier OP, the gate of the transistor PM1 is connected to the control voltage Vc, and the source of the transistor PM1 is connected to the drain of the transistor TS 2.

In the embodiment, a Wn signal is adopted to control the transistor TS1 and the transistor TS2 simultaneously, idata current is added to the resistor Rr1 to obtain a non-inverting input end Vp of a corresponding voltage input operational amplifier OP, meanwhile, when the transistor TS1 and the transistor TS2 are turned on, the transistor DT1 is driven to be turned on by the voltage Vg of the capacitor Cst, and the output current Ifb flows back to an inverting input end Vn of the operational amplifier OP through the transistor TS2 through the transistor PM1; and the source voltage Vfb of the transistor PM1 is made equal to the anode voltage VLED of the Micro LED in the display stage;

the output voltage Vdrv of the operational amplifier OP controls the charge and discharge of the capacitor Cst through the transistor TS1, and the voltage Vg is adjusted, so that the output current Ifb of the transistor DT1 is adjusted until the voltage of the Ifb current applied to the resistor Rr2, namely the voltage of the inverting input end Vn is the same as the voltage of the non-inverting input end Vp of the operational amplifier OP; the output voltage Vdrv of the operational amplifier OP is stable, the voltage Vg of the transistor DT1 is stable, the transistor DT1 outputs a stable current Ifb, and the voltage of two input ends of the operational amplifier OP is the same to obtain idata×rr1=ifb×rr2, i.e., ifb=idata×rr1/Rr2; the Ifb current magnitude is precisely scaled to the Idata current; the Ifb current is the output current of the transistor DT1, i.e., the transistor DT1 as a driving tube can accurately output Idata current.

Wherein the source-drain voltage drop Vds2 when the current Ifb flows through the transistor TS2 is equal to the source-drain voltage drop Vds3 when the driving current flows through the transistor TS 3; when vfb=vled, the drain-source voltages of the current driving stage and the display stage DT1 are also the same, so that the output currents of DT1 are the same. Thereby ensuring that the feedback current Ifb is equal to the Micro LED current. However, vfb and VLED cannot be guaranteed to be identical, and Vc voltage can be adjusted only according to the theoretical value of VLED voltage at different currents to obtain a similar Vfb. The driving tube DT1 works in a saturated state, the small deviation of the Vds voltage has little influence on the current precision, and even if the Vfb and the VLED are not completely equal, the output current changes little, so that the current precision can be greatly improved. In this embodiment, the transistor PM1 is applied to the source driving circuit, mainly considering the convenience of connection of the control voltage Vc and saving the space of the pixel circuit. The transistor PM1 may be added with a pixel current type driving circuit, but a voltage control line Vc needs to be added between the source driving circuit and the pixel current mirror driving circuit, and the PM1 transistor is added, so that the pixel circuit area is increased, and the space of the Micro LED lamp beads is reduced.

Example 2

As shown in fig. 2, the present embodiment discloses a Micro LED current mode driving circuit for improving the mirror image precision of a current mirror, in this embodiment, the pixel current mode driving circuit includes a transistor TS1 and a transistor TS2 with gate electrodes interconnected, a gate electrode connected to a source electrode of the transistor TS1, a drain electrode connected to a source electrode of the transistor TS2, a capacitor Cst connected between the gate electrode and the source electrode of the transistor DT2, a gate electrode connected to the source electrode of the transistor TS1, a source electrode connected to the source electrode of the transistor DT2, a source electrode connected to a drain electrode of the transistor DT1, a transistor TS3 with a gate electrode connected to an enable signal EN, and a LED with a positive electrode connected to the drain electrode of the transistor TS3 and a negative electrode grounded; wherein, the drain electrode of the transistor TS1 is connected with the output end of the operational amplifier OP, and the drain electrode of the transistor TS2 is connected with the source electrode of the transistor PM1; the source of the transistor DT1 and the source of the transistor DT2 are connected to a power source ELVD.

In this embodiment, the Wn signal is used to control the transistor TS1 and the transistor TS2 simultaneously, and Idata current is applied to the resistor Rr1 to obtain the non-inverting input terminal Vp of the corresponding voltage input operational amplifier OP, and when the transistor TS1 and the transistor TS2 are turned on, the voltage Vg of the capacitor Cst drives the transistor DT1 to be turned on, and the output current Ifb flows back to the inverting input terminal Vn of the operational amplifier OP through the transistor TS2, and the source voltage Vfb of the transistor PM1 is made equal to the anode voltage VLED of the Micro LED in the display stage.

Wherein the drain voltage vd1=vrb+vgs 2 of the transistor DT1, where Vgs2 is the gate-source voltage of DT 2. Since the current flowing through the transistor DT2 is the same in the current driving stage and the display stage, the gate-source voltage of the transistor DT2 is maintained constant, and the source-drain voltage Vds of the driving transistor in the current driving stage and the display stage is maintained constant, so that the DT1 outputs a high-precision current. The magnitude of the voltage Vrb is adjusted to adjust the magnitude of the drain voltage of the driving tube DT 1. Since the current driving stage and the display stage are both the DT1 output current and the source-drain voltage is ensured to be unchanged, even if the driving tube DT1 works in the linear region, good current accuracy output can be ensured. The present embodiment can appropriately reduce the power supply voltage ELVDD. Thus, the present embodiment can reduce driving power consumption and also can ensure current output accuracy.

Example 3

As shown in fig. 3, the present embodiment discloses a Micro LED current mode driving circuit for improving the mirror image precision of a current mirror, in this embodiment, the pixel current mode driving circuit includes a transistor TS1 and a transistor TS2 with gate electrodes interconnected, a gate electrode connected to a source electrode of the transistor TS1, a drain electrode connected to a source electrode of the transistor TS2, a capacitor Cst connected between the gate electrode and the source electrode of the transistor DT1, a source electrode connected to a drain electrode of the transistor DT1, a transistor TS3 with a gate electrode connected to an enable signal EN, and an LED with a positive electrode connected to the drain electrode of the transistor TS3 and a negative electrode grounded; wherein, the drain electrode of the transistor TS1 is connected with the output end of the operational amplifier OP, and the drain electrode of the transistor TS2 is connected with the source electrode of the transistor PM1; the source of the transistor DT1 is connected to the power source ELVDD.

In the present embodiment, the precision improving module is a transistor PM2 connected between a transistor DT1 and a transistor TS 3; wherein the drain of the transistor PM2 is connected to the source of the transistor DT 1; the source of the transistor PM2 is connected to the source of the transistor TS3, and the gate of the transistor PM2 is connected to the control voltage Vrb.

In the embodiment, a Wn signal is adopted to control a transistor TS1 and a transistor TS2 simultaneously, idata current is added to a resistor Rr1 to obtain a non-inverting input end Vp of a corresponding voltage input operational amplifier OP, meanwhile, when the transistor TS1 and the transistor TS2 are turned on, a voltage Vg of a capacitor Cst drives the transistor DT1 to be turned on, and output current Ifb flows back to an inverting input end Vn of the operational amplifier OP through the transistor TS 2;

Wherein the drain voltage vd1=vrb+vgs 2 of the transistor DT1, where Vgs2 is the gate-source voltage of PM 2. Since the current flowing through the transistor PM2 in the current driving stage and the display stage is the same, the gate-source voltage of the transistor PM2 is maintained unchanged, and the source-drain voltage Vds of the driving transistor in the current driving stage and the display stage is maintained unchanged, so that the DT1 outputs a high-precision current. The magnitude of the voltage Vrb is adjusted to adjust the magnitude of the drain voltage of the driving tube DT 1. Since the current driving stage and the display stage are both the DT1 output current and the source-drain voltage is ensured to be unchanged, even if the driving tube DT1 works in the linear region, good current accuracy output can be ensured. The present embodiment can appropriately reduce the power supply voltage ELVDD. Thus, the present embodiment can reduce driving power consumption and also can ensure current output accuracy.

Example 3

As shown in fig. 4, this embodiment discloses a Micro LED current mode driving circuit for improving mirror image precision of a current mirror, in this embodiment, the pixel current mode driving circuit includes a transistor TS1 and a transistor TS2 with gate electrodes interconnected, a gate electrode connected to a source electrode of the transistor TS1, a drain electrode connected to a source electrode of the transistor TS2, a capacitor Cst connected between the gate electrode and the source electrode of the transistor DT2, a gate electrode connected to a source electrode of the transistor TS1, a source electrode connected to the source electrode of the transistor DT2, a source electrode connected to a drain electrode of the transistor DT1, a transistor TS3 with a gate electrode connected to an enable signal EN, and an LED with a positive electrode connected to a drain electrode of the transistor TS3 and a negative electrode grounded; wherein, the drain electrode of the transistor TS1 is connected with the output end of the operational amplifier OP, and the drain electrode of the transistor TS2 is connected with the source electrode of the transistor PM1; the source of the transistor DT1 and the source of the transistor DT2 are connected to a power source ELVD.

In the present embodiment, the precision improving module is a transistor DT3 connected between a transistor DT1 and a transistor TS3 and a transistor DT4 connected between a transistor DT2 and a transistor TS 2; wherein the drain of the transistor DT3 is connected with the source of the transistor DT 1; the source of the transistor DT3 is connected to the source of the transistor TS3, and the drain of the transistor DT4 is connected to the source of the transistor DT 2; the source of the transistor DT4 is connected to the source of the transistor TS2, and the transistor DT4 is connected to the gate of the transistor DT3 and then connected to the control voltage Vrb.

In this embodiment, the Wn signal is used to control the transistor TS1 and the transistor TS2 simultaneously, and Idata current is applied to the resistor Rr1 to obtain the non-inverting input terminal Vp of the corresponding voltage input operational amplifier OP, and when the transistor TS1 and the transistor TS2 are turned on, the voltage Vg of the capacitor Cst drives the transistor DT2 to be turned on, and the output current Ifb flows back to the inverting input terminal Vn of the operational amplifier OP through the transistor TS 2.

The output voltage Vdrv of the operational amplifier OP controls the charge and discharge of the capacitor Cst through the transistor TS1, and the voltage Vg is adjusted, so that the output current Ifb of the transistor DT1 is adjusted until the voltage of the Ifb current applied to the resistor Rr2, namely the voltage of the inverting input end Vn is the same as the voltage of the non-inverting input end Vp of the operational amplifier OP; the output voltage Vdrv of the operational amplifier OP is stable, the voltage Vg of the transistor DT1 is stable, the transistor DT1 outputs a stable current Ifb, and the voltage of two input ends of the operational amplifier OP is the same to obtain idata×rr1=ifb×rr2, i.e., ifb=idata×rr1/Rr2; the Ifb current magnitude is precisely scaled to the Idata current; and the gate-source voltages Vgs of the transistor DT1 and the transistor DT2 are the same; the output current of the transistor DT1 can accurately mirror the Ifb current output of the transistor DT 2; i.e. the transistor DT1 as a driving tube can accurately output Idata current.

Wherein the drain voltage vd2=vrb+vgs 4 of the transistor DT2, where Vgs4 is the gate-source voltage of DT4, and the drain voltage vd1=vrb+vgs 3 of the same transistor DT1, where Vgs3 is the gate-source voltage of DT 3. The parameters of TS2 and TS3 are reasonably designed such that Vgs 4=vgs 3, vd2=vd1, and vds2=vds1. Thereby improving the current mirror accuracy of DT2 and DT 1. Adjusting the magnitude of the Vrb voltage may adjust the voltage of Vd2 and Vd 1. The embodiment can accurately control Vds2 and Vds1 to be equal, so that Vd2 and Vd1 transistors can ensure high-precision current mirror image, and proper reduction of the power supply voltage ELVDD can not influence the current mirror image precision. Therefore, the embodiment can reduce the power supply voltage and the driving power consumption, and can improve the current mirror image precision.

The above embodiment is only one of the preferred embodiments of the present invention, and should not be used to limit the scope of the present invention, but all the insubstantial modifications or color changes made in the main design concept and spirit of the present invention are still consistent with the present invention, and all the technical problems to be solved are included in the scope of the present invention.

Claims

1. The Micro LED current type driving circuit for improving the mirror image precision of the current mirror is characterized by comprising a source electrode driving circuit, a pixel point current type driving circuit and a precision improving module; the precision improvement module is used for enabling the drain-source voltage of a driving tube in the pixel point current type driving circuit to be the same in a current driving stage and a display stage;

the source driving circuit is composed of an operational amplifier OP and a resistor Rr1 and a resistor Rr2, one end of the resistor Rr1 and one end of the resistor Rr2 are respectively connected with two input ends of the operational amplifier OP, and the output end and the inverting input end Vn of the operational amplifier OP are connected with the pixel point current type driving circuit; the non-inverting input end of the operational amplifier OP inputs the current Idata;

the pixel point current type driving circuit comprises a transistor TS1 and a transistor TS2, wherein the grid electrode of the transistor TS1 is connected with the source electrode of the transistor TS1, the drain electrode of the transistor TS2 is connected with the source electrode of the transistor DT1, a capacitor Cst is connected between the grid electrode and the source electrode of the transistor DT1, the source electrode of the transistor TS1 is connected with the drain electrode of the transistor DT1, the grid electrode of the transistor TS3 is connected with an enable signal EN, and the anode of the transistor TS3 is connected with the drain electrode of the transistor TS3 and the cathode of the transistor TS3 is grounded; the drain electrode of the transistor TS1 is connected with the output end of the operational amplifier OP, and the drain electrode of the transistor TS2 is connected with the inverting input end Vn of the operational amplifier OP; the source electrode of the transistor DT1 is connected with a power supply ELVDD; the precision improving module is connected between the drain of the transistor TS2 and the inverting input end Vn of the operational amplifier OP or between the drain of the transistor DT1 and the source of the transistor TS 3;

or the pixel point current type driving circuit comprises a transistor TS1 and a transistor TS2 with grid electrodes connected, wherein the grid electrodes are connected with the source electrode of the transistor TS1, the drain electrode is connected with the source electrode of the transistor TS2, the transistor DT2 is connected between the grid electrodes of the transistor DT2 and a capacitance Cst between the source electrodes, the grid electrodes are connected with the source electrode of the transistor TS1, the source electrode is connected with the source electrode of the transistor DT2, the source electrode is connected with the drain electrode of the transistor DT1, the grid electrode is connected with a transistor TS3 of an enable signal EN, and the anode electrode is connected with the drain electrode of the transistor TS3 and the cathode electrode is grounded; the drain of the transistor TS1 is connected with the output end of the operational amplifier OP, and the drain of the transistor TS2 is connected with the inverting input end Vn of the operational amplifier OP; the source of the transistor DT1 and the source of the transistor DT2 are connected to a power source ELVD; the precision improving module is connected between the drain of the transistor TS2 and the inverting input Vn of the operational amplifier OP or between the drain of the transistor DT1, the drain of the transistor DT2, the source of the transistor TS2 and the source of the transistor TS 3.

2. The Micro LED current type driving circuit for improving the mirror image precision of a current mirror according to claim 1, wherein the precision improving module is a transistor PM1; the drain of the transistor PM1 is connected to the inverting input Vn of the operational amplifier OP, the gate of the transistor PM1 is connected to the control voltage Vc, and the source of the transistor PM1 is connected to the drain of the transistor TS 2.

3. The Micro LED current mode driving circuit for improving mirror image precision of a current mirror according to claim 1, wherein when the pixel point current mode driving circuit is a transistor TS1 and a transistor TS2 including a gate electrode connected to each other, a gate electrode connected to a source electrode of the transistor TS1, a drain electrode connected to a source electrode of the transistor TS2, a capacitor Cst connected between the gate electrode and the source electrode of the transistor DT1, a source electrode connected to a drain electrode of the transistor DT1, a transistor TS3 having a gate electrode connected to an enable signal EN, and a LED having a positive electrode connected to the drain electrode of the transistor TS3 and a negative electrode grounded; the drain electrode of the transistor TS1 is connected with the output end of the operational amplifier OP, and the drain electrode of the transistor TS2 is connected with the inverting input end Vn of the operational amplifier OP; when the source electrode of the transistor DT1 is connected with the power source ELVDD;

the precision improving module is a transistor PM2 connected between a transistor DT1 and a transistor TS 3; wherein the drain of the transistor PM2 is connected to the source of the transistor DT 1; the source of the transistor PM2 is connected to the source of the transistor TS3, and the gate of the transistor PM2 is connected to the control voltage Vrb.

4. The Micro LED current-mode driving circuit for improving mirror image precision of a current mirror according to claim 1, wherein when the pixel point current-mode driving circuit is a transistor TS1 and a transistor TS2 including a gate interconnection, the gate is connected to a source of the transistor TS1, the drain is connected to a source of the transistor TS2, the transistor DT2 is connected to a capacitor Cst between the gate and the source of the transistor DT2, the gate is connected to a source of the transistor TS1, the source is connected to a source of the transistor DT2, the source is connected to a drain of the transistor DT1, the gate is connected to a transistor TS3 of an enable signal EN, and the anode is connected to a drain of the transistor TS3 and the cathode is grounded; the drain of the transistor TS1 is connected with the output end of the operational amplifier OP, and the drain of the transistor TS2 is connected with the inverting input end Vn of the operational amplifier OP; when the source electrode of the transistor DT1 and the source electrode of the transistor DT2 are connected to the power source ELVD;

the precision improving module is a transistor DT3 connected between the transistor DT1 and the transistor TS3 and a transistor DT4 connected between the transistor DT2 and the transistor TS 2; wherein the drain of the transistor DT3 is connected with the source of the transistor DT 1; the source of the transistor DT3 is connected to the source of the transistor TS3, and the drain of the transistor DT4 is connected to the source of the transistor DT 2; the source of the transistor DT4 is connected to the source of the transistor TS2, and the transistor DT4 is connected to the gate of the transistor DT3 and then connected to the control voltage Vrb.

5. The realization method of the Micro LED current type driving circuit for improving the mirror image precision of the current mirror is characterized in that the realization method is used for enabling the current type driving circuit of claim 2 to generate driving current, wn signals are adopted to control a transistor TS1 and a transistor TS2 simultaneously, idata current is added to a resistor Rr1 to obtain a corresponding voltage to be input into a non-inverting input end Vp of an operational amplifier OP, meanwhile, when the transistor TS1 and the transistor TS2 are turned on, a voltage Vg of a capacitor Cst drives the transistor DT1 to be turned on, and output current Ifb flows back to an inverting input end Vn of the operational amplifier OP through the transistor TS2 through the transistor PM1; and the source voltage Vfb of the transistor PM1 is made equal to the anode voltage VLED of the Micro LED in the display stage;

when the pixel current type driving circuit is a transistor TS1 and a transistor TS2 with interconnected gates, the gate is connected with the source of the transistor TS1, the drain is connected with the source of the transistor TS2, the transistor DT1 is connected with a capacitor Cst between the gate and the source of the transistor DT1, the source is connected with the drain of the transistor DT1, the gate is connected with a transistor TS3 of an enable signal EN, and the anode is connected with the drain of the transistor TS3 and the cathode is grounded; the drain electrode of the transistor TS1 is connected with the output end of the operational amplifier OP, and the drain electrode of the transistor TS2 is connected with the inverting input end Vn of the operational amplifier OP; when the source electrode of the transistor DT1 is connected with the power supply ELVDD, the Ifb current is the output current of the transistor DT1, namely the transistor DT1 as a driving tube can accurately output Idata current;

when the pixel point current type driving circuit is a transistor TS1 and a transistor TS2 which are connected with each other by a grid electrode, the grid electrode is connected with a source electrode of the transistor TS1, the drain electrode is connected with the source electrode of the transistor TS2, the transistor DT2 is connected with a capacitor Cst between the grid electrode and the source electrode of the transistor DT2, the grid electrode is connected with the source electrode of the transistor TS1, the source electrode is connected with the source electrode of the transistor DT2, the source electrode is connected with the drain electrode of the transistor DT1, the grid electrode is connected with a transistor TS3 of an enable signal EN, and the anode is connected with the drain electrode of the transistor TS3 and the cathode is grounded; the drain of the transistor TS1 is connected with the output end of the operational amplifier OP, and the drain of the transistor TS2 is connected with the inverting input end Vn of the operational amplifier OP; when the source of the transistor DT1 and the source of the transistor DT2 are connected to the power source ELVD, the gate-source voltages Vgs of the transistor DT1 and the transistor DT2 are the same; the output current of the transistor DT1 can accurately mirror the Ifb current output of the transistor DT 2; namely, the transistor DT1 as a driving tube can accurately output Idata current;

6. The realization method of the Micro LED current type driving circuit for improving the mirror image precision of the current mirror is characterized in that the realization method is used for enabling the current type driving circuit in claim 3 to generate driving current, wn signals are adopted to control a transistor TS1 and a transistor TS2 simultaneously, idata current is added to a resistor Rr1 to obtain a corresponding voltage to be input into a non-inverting input end Vp of an operational amplifier OP, meanwhile, when the transistor TS1 and the transistor TS2 are opened, a voltage Vg of a capacitor Cst drives the transistor DT1 to be opened, and output current Ifb flows back to an inverting input end Vn of the operational amplifier OP through the transistor TS 2;

7. A method for implementing a Micro LED current mode driving circuit for improving the mirror image precision of a current mirror, which is characterized by being used for enabling the current mode driving circuit according to claim 4 to generate driving current, and is characterized in that a Wn signal is adopted to simultaneously control a transistor TS1 and a transistor TS2, idata current is added to a resistor Rr1 to obtain a corresponding voltage to be input into a non-inverting input terminal Vp of an operational amplifier OP, and simultaneously when the transistor TS1 and the transistor TS2 are turned on, a voltage Vg of a capacitor Cst drives the transistor DT2 to be turned on, and an output current Ifb flows back to an inverting input terminal Vn of the operational amplifier OP through the transistor TS 2;