CN213751895U

CN213751895U - AMOLED display screen source electrode medium voltage level driving circuit and AMOLED display screen

Info

Publication number: CN213751895U
Application number: CN202020350519.3U
Authority: CN
Inventors: 周剑; 肖宏; 覃正才; 高金广
Original assignee: New Vision Micro Inc
Current assignee: Shanghai Xinxiang Microelectronics Co.,Ltd.
Priority date: 2020-03-19
Filing date: 2020-03-19
Publication date: 2021-07-20
Anticipated expiration: 2030-03-19

Abstract

The utility model provides a can save chip area's source pole middling pressure level drive circuit for in the theoretical AMOLED display screen, a serial communication port, circuit device adopts the processing procedure technology device that is less than 8V among the voltage drive circuit. Preferably, the process device with the voltage lower than 8V is a 6V process device. A corresponding AMOLED display screen is also provided. Through the utility model provides a drive control circuit for need not use 8V processing procedure technology device, but be less than 8V's processing procedure technology device, for example 6V voltage drive technology device. Therefore, the chip area is reduced, the cost is reduced, and the power consumption is saved. Further, through the utility model provides a drive control circuit can realize containing the cost control who corresponds above-mentioned display driver unit's display driver chip to can effectively promote display driver chip's performance.

Description

AMOLED display screen source electrode medium voltage level driving circuit and AMOLED display screen

Technical Field

The utility model relates to a semiconductor field especially relates to the AMOLED display screen, involves in particular to the source middling pressure level drive circuit who is used for the AMOLED display screen to and the AMOLED display screen that corresponds.

Background

A simplified functional schematic diagram of a conventional AMOLED display driver chip is shown in fig. 1. The image data is generated by a digital logic circuit, and then a digital signal of a low level is converted into a digital signal of a high level by a level shifter to conform to an operating voltage of a subsequent circuit. And according to the voltage mapped by the set gamma curve, the digital-to-analog converter converts the digital signal into the analog voltage required by the AMOLED pixel circuit. And finally, the pixel analog voltage drives the pixel circuit through the source buffer circuit. The source or the positive power supply of the data driver (hereinafter referred to as source driver) in the AMOLED display driver chip is denoted as AVDD, and correspondingly, the negative source driver power supply is denoted as AVSS, and the current mainstream design specification is that AVDD adopts a voltage of 6V, and correspondingly, AVSS is a voltage of 0V. The source driver and associated circuitry is shown in fig. 1.

Specifically, the positive and negative power supplies of the "Gamma reference voltage generator" are denoted as AVDD and AVSS, respectively. The circuit generates two reference voltages VGMP, VGSP for the subsequent Gamma circuit. In the figure, the Gamma circuit is only a simplified diagram, and Gamma uses VGMP, VGSP generates Gamma gray scale voltage VGS (the gray scale voltage quantity is determined according to the gray scale voltage requirement of the product and the product architecture) through a resistor divider, a voltage selector and a voltage buffer. And the VGS is output to each source output channel.

Each output channel has "digital logic" that stores and outputs display data, and the power supply and output voltage range is logic level DVDD-DVSS, typically 1.5V or 1.2V. The "level shifter" converts the logic level signal to the AVDD/AVSS power domain, which is currently 6.0V/0V.

The gray scale voltage selector selects the required gray scale voltage according to the AVDD-AVSS level signal. The "source buffer" output Sout is the same as the input gray scale voltage, but has enhanced driving capability to drive the pixel circuit.

The operating voltage of the circuit in the dashed box is AVDD/AVSS, i.e., generally 6V/0V. Therefore, the circuit adopts a device of 6V process technology. Taking the source buffer output stage circuit as an example, for example, it is preferable to refer to the contents shown in fig. 2 in detail.

However, as the color resolution and the image contrast of the next generation display screen are improved, the operating voltage of the display screen needs to be increased from 6V to 8V, i.e., the operating voltage of the AMOLED display driving chip needs to be increased to 8V. Under this operating condition, in the prior art, a device using 8V process is required to implement the circuit design, as shown in fig. 3. The main requirement of the device adopting the 8V process technology is to make the corresponding output voltage be 8V, so as to meet the requirement of the working voltage of the AMOLED display driving chip.

Specifically, when PGATE is 0V and NGATE is 0V, the PMOS turns on and outputs the AVDD voltage. When Sout needs to output 8V AVDD, the voltage difference between two PMOS source gate terminals, two drain gate terminals, etc. (specifically, source terminal: AVDD, gate terminal: PGATE, drain terminal: Sout) is 8V. The voltage difference between the drain and source terminals of the NMOS, between the drain and gate terminals (specifically, the drain terminal Sout, the source terminal AVSS, and the gate terminal NGATE) is 8V. The circuit structure shown in fig. 3 needs 8V process devices to realize the circuit structure, so that the output of the circuit is 8V voltage.

When NGATE is AVDD, PGATE is AVDD, NMOS is turned on, and AVSS voltage, that is, 0V is output. It is understood by those skilled in the art that when the output AVDD is 8V, the 8V device or 8V process is also required to achieve an external output voltage of 8V, similar to the situation described in the previous paragraph.

In view of the above requirements, for the source medium voltage level driving circuit of the AMOLED display screen, a device of a 6V process technology is adopted in the conventional source medium voltage level driving circuit technology of the AMOLED display screen, and a device of an 8V process technology is required for the next generation of AMOLED display screen. Compared with a device manufactured by a 6V process technology, the area of the 8V process device is larger than that of the 6V process device, so that the area of a chip is large, and the power consumption is increased. There is a need to provide a solution to reduce chip area and try to reduce power consumption.

SUMMERY OF THE UTILITY MODEL

To the defects in the prior art, the present invention is directed to providing a source medium voltage level driving circuit capable of saving power consumption in an AMOLED display screen. Based on this purpose, based on an aspect of the utility model provides a theoretical AMOLED display screen source middling pressure level drive circuit, include the voltage drive circuit of the push-pull structure of constituteing by PMOS transistor T1 and NMOS transistor T2, voltage drive circuit's mains voltage shows to be AVDD, voltage drive circuit's ground voltage shows to be AVSS, its characterized in that, circuit device adopts the processing procedure technology device that is less than 8V among the voltage drive circuit.

Preferably, the process device with the voltage lower than 8V is a 6V process device.

Preferably, the AVSS voltage is in a range of 1V to 3V.

Preferably, the AVSS voltage is 2V.

Preferably, the AVDD voltage is 8V to satisfy an operating voltage of the circuit device corresponding to the medium voltage region.

Preferably, any one or more of the following devices in the AMOLED display screen driving chip provides a voltage through the source medium voltage level driving circuit:

-a source buffer circuit;

-a digital-to-analog converter; and

-a gray scale circuit selector.

According to another aspect of the present invention, there is also provided a display driving circuit in an AMOLED display screen, wherein the source medium voltage level driving circuit in the AMOLED display screen adopts any one of the source medium voltage level driving circuits described above.

According to another aspect of the present invention, there is also provided a schematic AMOLED display screen, which includes the display driving circuit.

Through the utility model provides a drive control circuit for need not use 8V processing procedure technology device in next generation AMOLED display screen, but be less than 8V's processing procedure technology device, for example 6V voltage drive technology device. Therefore, the chip area is reduced, the cost is reduced, and the power consumption is saved. Further, through the utility model provides a drive control circuit can realize containing the cost control who corresponds above-mentioned display drive unit's display control chip, further deepening, refine to the chip industry and have important meaning.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is a schematic diagram of a circuit structure of an AMOLED display screen source medium voltage level driving circuit according to the prior art;

FIG. 2 is a circuit diagram illustrating a source medium voltage level driving circuit for a conventional AMOLED display panel according to the prior art;

FIG. 3 is a schematic circuit diagram of a source medium voltage level driving circuit for an AMOLED display screen according to the prior art;

fig. 4 is a schematic circuit diagram of a schematic source medium voltage level driving circuit of an AMOLED display according to an embodiment of the present invention; and

fig. 5 is a schematic circuit diagram of a schematic source medium voltage level driving circuit of an AMOLED display according to an embodiment of the present invention.

Detailed Description

For better making the technical solution of the present invention clearly show, the present invention is further explained below with reference to the accompanying drawings, wherein fig. 4 shows a schematic circuit structure diagram of an embodiment of the present invention for a schematic source medium voltage level driving circuit of an AMOLED display screen. Specifically, the utility model provides a fundamental AMOLED display screen source electrode medium voltage level drive circuit, include the voltage drive circuit of the push-pull structure that comprises PMOS transistor T1 and NMOS transistor T2, the supply voltage of voltage drive circuit is denoted as AVDD, the ground voltage of voltage drive circuit is denoted as AVSS, specifically, the circuit device adopts the processing procedure technology device that is less than 8V among the voltage drive circuit, namely the technology device as shown in 4.

Further, those skilled in the art will understand that, compared with the source medium voltage level driving circuit adopted in the prior next generation AMOLED display screen, the process device shown in fig. 4 does not need to adopt a process device of 8V, but adopts a process device of less than 8V, and in particular, can be selected in combination with the process device of less than 8V that can be provided by the prior manufacturers. For example, the process device with the voltage lower than 8V is preferably a 6V process device. In other embodiments, a 7V process device, or a process device between 6V and 8V may be used.

Further, those skilled in the art will understand that the corresponding AVSS voltage may be different depending on the adopted process device below 8V, for example, when the source medium voltage level driving circuit adopts a 6V process device, i.e., a 6V level driving circuit, the AVSS voltage is preferably 2V. Further, those skilled in the art understand that the selection of the AVSS voltage is preferably used to ensure that the AVDD voltage output by the source medium voltage level driving circuit is 8V, so as to satisfy the requirement of the next generation AMOLED display screen provided by the present invention for the voltage provided by the source medium voltage level driving circuit to be 8V.

Further, those skilled in the art will appreciate that in other embodiments, the AVSS voltage may be different based on the process device below 8V. For example, when the process device below 8V is a 7V process device, the AVSS voltage is preferably 1V. For another example, in another variation, in an extreme case, when the process device below 8V is a 5V process device, it is preferable that the AVSS voltage is 3V, and those skilled in the art understand that although such a variation is not often used, it can be a specific solution in an extreme case.

In conjunction with the embodiment shown in fig. 4, it is understood by those skilled in the art that the AVDD voltage is preferably 8V to satisfy the operating voltage of the circuit device corresponding to the medium voltage region.

From the analysis of the operating characteristics of the currently practical AMOLED display screen, it is found that, in order to avoid damaging the display screen system by an excessive current, the source driving circuit of the AMOLED driving chip outputs Sout with a minimum voltage of about 2V. Those skilled in the art understand that the lower the voltage, the brighter the display screen, the brightness corresponding to 2V already makes the display screen bright enough to meet the requirements of the AMOLED display screen. Accordingly, 0V is not reached. Based on this application characteristic, in a preferred embodiment, a design circuit using 6V process device instead of 8V process device is provided. In this circuit, a positive voltage (e.g., 2V) is connected to the source (S) terminal of the 6V NMOS device instead of the 0V ground as the source driving negative supply (noted PAVSS). Taking the source buffer output stage as an example, it is preferable to be the case shown in fig. 4 described above.

Further, as will be understood by those skilled in the art with reference to fig. 2, 3 and 4, in the preferred embodiment of the present invention, a 6V process device is preferably used, but the AVSS voltage of the device is not 0V as shown in fig. 2, nor 0V as shown in fig. 3, but is preferably 2V. Of course, in other variations, the AVSS voltage may also be 1-3V, which is adjusted according to the performance of the adopted process device lower than 8V, and such variations are within the scope of the present invention and are not described herein.

Further, those skilled in the art understand that when PGATE is 2V, NGATE is 2V, PMOS turns on, outputting 8V AVDD voltage. The voltage difference between the two ends of the PMOS source gate and the two ends of the drain gate (source end: AVDD, gate end: PGATE, drain end: Sout) is 6V. The voltage difference between the two drain-source terminals of the NMOS, the two drain-gate terminals of the NMOS (drain terminal Sout, source terminal AVSS, gate terminal NGATE) is 6V. Through the embodiment shown in fig. 4 and the above description, those skilled in the art understand that, in a preferred embodiment, a 6V process device may be used to implement a medium voltage driving circuit in a driving chip of a next generation AMOLED display screen, that is, the medium voltage level driving circuit provides a voltage output of 8V, so as to ensure that the next generation AMOLED display screen can work normally.

When NGATE is 8V, PGATE is 8V, NMOS is turned on, and 2V PAVSS voltage is output. The situation is similar to that of the above-mentioned output AVDD, and only a 6V device or process is needed to implement the medium voltage level driving circuit to provide a voltage output of 8V.

Furthermore, in conjunction with the embodiment shown in fig. 4, it is understood by those skilled in the art that, preferably, any one or more of the following devices in the driving chip of the AMOLED display screen are provided with a voltage through the medium voltage source level driving circuit:

-a source buffer circuit;

-a digital-to-analog converter; and

-a gray scale circuit selector.

Further, those skilled in the art understand that, for different embodiments and implementation requirements, the modification of the improved scheme provided by the present invention can be performed on the medium voltage level driving circuit required in the AMOLED display screen, so as to greatly reduce the chip area and reduce the power consumption. These embodiments and variations are within the scope of the present invention, and are not described herein.

In another embodiment of the present invention, there is also provided a schematic AMOLED display screen, which is compared with the source medium voltage level driving circuit shown in fig. 4, and preferably, the source medium voltage level driving circuit adopts a process device lower than 8V.

On the basis of the embodiment shown in fig. 4, fig. 5 shows a schematic circuit structure diagram of the medium voltage level driving circuit in the source of the principle AMOLED display screen according to an embodiment of the present invention.

Specifically, those skilled in the art understand that the source driving negative voltage PAVSS can be generated from the chip or generated by other methods on the system using the existing power source of the system.

In a preferred embodiment, the system's existing power supply is used for driving, in which case system power consumption can also be saved. Specifically, when the display driving chip of the next generation AMOLED display screen operates, current flows from the AVDD terminal of the power supply and flows into the PAVSS power supply. The current flowing in the PAVSS can be used as the current consumed by other modules of the system, so that the power consumption of the whole system is saved. For example, referring to fig. 5, the current provided by the PAVSS power generator can be greatly reduced, referring to the current schematic corresponding to the arrow at the bottom left, thereby saving power consumption.

More specifically, those skilled in the art understand that:

1. the method for operating the AMOLED driving chip circuit at the 8V working voltage can be realized by changing the 'ground potential' AVSS of the circuit from 0V to the positive voltage PAVSS and using a 6V process.

2. Using system power as an AVSS saves system power consumption.

With reference to the above-mentioned embodiments shown in fig. 4 and fig. 5, those skilled in the art understand that, although the source medium voltage level driving circuit is required to provide the 8V AVDD output voltage for the next generation AMOLED display screen, based on the circuit structure provided by the present invention, by using the process device lower than 8V as the medium voltage level driving circuit, the medium voltage level driving circuit required for the next generation AMOLED display screen can be provided in an angle of saving chip area and reducing power consumption compared to the existing 8V process device, thereby implementing the improved next generation AMOLED display screen. Furthermore, in this way, the existing 6V process design and manufacturing chips can be reused, especially for the display chips of the next generation AMOLED display screen. The 6V process technology has small device area, small chip area and great competitiveness in cost.

Furthermore, those skilled in the art understand that, for all medium voltage level driving circuits in the next generation AMOLED display screen, the process device less than 8V provided by the present invention can be adopted as the driving circuit, and these embodiments are all within the scope of the present invention and are not described herein again.

The foregoing description of the specific embodiments of the invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes and modifications may be made by those skilled in the art within the scope of the appended claims without departing from the spirit of the invention.

Claims

1. A medium voltage level driving circuit of an AMOLED display screen source electrode comprises a voltage driving circuit of a push-pull structure consisting of a PMOS transistor T1 and an NMOS transistor T2, wherein the power voltage of the voltage driving circuit is represented as AVDD, the ground voltage of the voltage driving circuit is represented as AVSS, and the medium voltage level driving circuit is characterized in that circuit devices in the voltage driving circuit adopt process devices lower than 8V.

2. The medium voltage source driver circuit of claim 1, wherein said supply voltage AVDD is at a potential of 8V.

3. The medium voltage source driver circuit of claim 1, wherein said less than 8V process device is a 6V process device.

4. The medium voltage source driver circuit of claim 1, wherein the AVSS voltage is in the interval of 1V to 3V.

5. The medium voltage source level driver circuit of claim 4, wherein the AVSS voltage is 2V.

6. The medium voltage source level driving circuit according to claim 1, 2, 3, 4 or 5, wherein any one or any more of the following devices in the AMOLED display screen driving chip are provided with voltage through the medium voltage source level driving circuit:

-a source buffer circuit;

-a digital-to-analog converter; and

-a gray scale circuit selector.

7. An AMOLED display screen, characterized in that the display driving circuit in the AMOLED display screen adopts the medium voltage source level driving circuit as claimed in any one of claims 1-6.