Circuit structure for improving AMOLED power failure

Abstract

The utility model discloses a circuit structure for improving AMOLED power failure, the circuit structure comprises a first chip, a second chip and an AMOLED display screen, the first chip is electrically connected with the AMOLED display screen to output a positive driving voltage ELVDD and a negative driving voltage ELVSS, the second chip comprises an ELVDD switching circuit, an ELVSS switching circuit and a grounding circuit, the ELVDD switching circuit is electrically connected with the first chip, and the ELVSS switching circuit is electrically connected with the second chip. One end of the second chip ELVDD switching circuit is connected with a first pin of the first chip in series, one end of the second chip ELVSS switching circuit is connected with a second pin of the first chip in series, and the other ends of the ELVDD and the ELVSS switching circuit are connected with a grounding circuit, so that supply and management of a power supply are cooperatively controlled through the two chips, and through the design of the ELVDD and the ELVSS switching circuits, the reliability of the power supply is improved. The problem that an AMOLED (Active Matrix / Organic Light Emitting Diode) cannot be cleaned due to abnormal power-off caused by slow power-off during power-off of ELVDD and ELVSS is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of an AMOLED power management circuit, in particular to the field of improving the AMOLED power-off circuit structure. Background Art

[0002] AMOLED is widely used in smart watch projects due to its bright display, high contrast and small screen. Due to the voltage requirement of AMOLED itself when emitting light, it is necessary to supply a positive voltage ELVDD and a negative voltage ELVSS to the AMOLED Panel to meet the AMOLED display requirements. At this time, people will use a power management IC to supply ELVDD and ELVSS, but because the ELVDD and ELVSS of the power management IC have residual charges when powered off, ELVDD and ELVSS power off slowly, which makes the AMOLED power off abnormally, and sometimes a white line or screen flickering will appear. Therefore, people will match MOS and capacitors and resistors outside ELVDD and ELVSS to make ELVDD and ELVSS discharge quickly, but this will use more components to affect the structural space of smart watches, and on the other hand, it will increase costs. Utility Model Content

[0003] The utility model aims to overcome the shortcomings of the prior art and provide a low-cost circuit structure which utilizes dual ICs to provide voltage in coordination and can power off the AMOLED normally.

[0004] The purpose of this utility model is achieved through the following technical solutions:

[0005] A circuit structure for improving power failure of an AMOLED, the circuit structure comprising a first chip, a second chip and an AMOLED display screen, the first chip being electrically connected to the AMOLED display screen, a first pin of the first chip being connected to the AMOLED display screen to output a positive driving voltage ELVDD, a second pin of the first chip being connected to the AMOLED display screen to output a negative driving voltage ELVSS, the second chip comprising an ELVDD switching circuit, an ELVSS switching circuit and a grounding circuit, one end of the ELVDD switching circuit of the second chip being connected in series with the first pin of the first chip, one end of the ELVSS switching circuit of the second chip being connected in series with the second pin of the first chip, and the other ends of the ELVDD and ELVSS switching circuits being connected to the grounding circuit.

[0006] The first chip is a power management IC, and the second chip is a driver IC.

[0007] In this way, ELVDD and ELVSS are not only connected to the power management IC, but also connected to the driver IC. According to the internal setting conditions of the driver IC itself, the power supply of ELVDD and ELVSS terminals can be switched from the power management IC to the driver IC when low power supply is performed.

[0008] The driver IC is designed with a switch circuit. When the normal power supply requires ELVDD and ELVSS to be powered off, the power management IC ELVDD and ELVSS can be set to zero. At this time, ELVDD and ELVSS will slowly lose power, and then the ELVDD switch circuit and the ELVSS switch circuit inside the driver IC are closed to ground ELVDD and ELVSS, so that the voltage of ELVDD and ELVSS of the power management IC is instantly powered off to zero. When low power consumption is displayed, since the power supply of ELVDD and ELVSS ends can be switched from the power management IC to the driver IC, ELVDD and ELVSS are powered by the driver IC. When ELVDD and ELVSS need to be set to zero, the ELVDD switch circuit and the ELVSS switch circuit can be closed inside the driver IC to ground ELVDD and ELVSS, so that the voltage of ELVDD and ELVSS is instantly powered off to zero.

[0009] The beneficial effect of the utility model is that two chips are used to collaboratively control the supply and management of power supply, and through the design of ELVDD and ELVSS switching circuits, the problem of slow power-off of ELVDD and ELVSS, which causes abnormal power-off of AMOLED and inability to clear the screen, is solved. This configuration can provide a more flexible and sophisticated power management solution to meet the performance, power consumption and cost requirements in different scenarios, and the power management IC has fewer peripheral components such as MOS tubes, capacitors and resistors, saving costs and making the circuit of the AMOLED smart watch more streamlined, thereby reducing space. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0011] Figure 1 The figure is a schematic diagram of the circuit structure of an embodiment of the utility model. DETAILED DESCRIPTION

[0012] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively with reference to the relevant drawings. The drawings provide preferred embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly and comprehensively understood.

[0013] It should be noted that the term "connection" used in this article includes not only the connection between two things but also the connection with an intermediate component or peripheral circuit structure between the two things. The terms "first", "second" and similar expressions used in this article are for illustrative purposes only and do not represent the only implementation method.

[0014] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0015] See also Figure 1 The circuit structure for improving the power failure of AMOLED in one embodiment of the utility model comprises a first chip 10, a second chip 20 and an AMOLED display screen 30, wherein the first chip 10 is electrically connected to the AMOLED display screen 30, a first pin 101 of the first chip 10 is connected to the AMOLED display screen 30 to provide a positive driving voltage ELVDD, a second pin 102 of the first chip 10 is connected to the AMOLED display screen 30 to provide a negative driving voltage ELVSS, the second chip 20 comprises an ELVDD switch circuit 201, an ELVSS switch circuit 202 and a ground circuit 203, one end of the ELVDD switch circuit 201 of the second chip 20 is connected in series with the first pin 101 of the first chip 10, one end of the ELVSS switch circuit 202 of the second chip 20 is connected in series with the second pin 102 of the first chip 10, and the other ends of the ELVDD and ELVSS switch circuits are connected to the ground circuit 203.

[0016] In the circuit structure of this embodiment, after the first chip 10 receives the enable signal EN provided externally, it starts working and outputs the corresponding power supply voltage for the AMOLED display screen. Once the SWIRE signal input recognizes the instruction or data represented by the signal, the first chip 10 will perform corresponding operations such as adjusting the output voltage, switching the working mode, enabling or disabling certain functions according to its internal functions and settings. ELVDD and ELVSS are not only connected to the first chip 10, but also connected to the second chip 20. When the first chip 10 receives external instructions for low-power supply or power-off operation, the power supply of ELVDD and ELVSS ends can be switched from the first chip 10 to the second chip 20. Through the ELVDD switching circuit and ELVSS switching circuit built into the second chip 20, when it is necessary to turn off ELVDD and ELVSS, the voltages of ELVDD and ELVSS can be instantly powered off to zero.

[0017] In this embodiment, the first chip 10 is a power management IC, which has a built-in boost converter and a buck converter for converting the received external voltage into a required voltage to supply power to the AMOLED display.

[0018] In this embodiment, the first chip 10 is configured with a timing controller or a logic circuit so that when ELVDD and ELVSS need to be turned off, the voltage value is gradually reduced first, so that the load has enough time to adapt to the voltage change and complete the necessary operations, thereby reducing the impact on the load caused by the voltage mutation.

[0019] In this embodiment, the first chip 10 is provided with an AVin pin for receiving external power supply, and is provided with a CTRL pin for connecting the boost converter and the buck converter, so that the output voltage value can be programmed and the output voltage can be accurately controlled.

[0020] In this embodiment, the second chip 20 is a driver IC, and the driver IC 20 interacts with the above-mentioned power management IC 10 through a communication interface. By writing control logic, the voltage supply function is switched from the power management IC 10 to the driver IC 20 in low power mode. According to the interaction instruction information, it is confirmed that the driver IC supplies ELVDD and ELVSS or closes the ELVDD and ELVSS switches.

[0021] In this embodiment, the second chip 20 includes a voltage detection circuit to detect the voltage value output by the first chip 10. When the voltage value is detected to be lower than the set value, the ELVDD and ELVSS outputs of the first chip 10 are turned off, and the second chip 20 is turned on at the same time, thereby ensuring that the switching operation is performed at the correct time and under the correct conditions.

[0022] In the implementation mode of the embodiment, when the normal display requires ELVDD and ELVSS to be powered off, the ELVDD and ELVSS of the power management IC 20 are modified to zero by setting. At this time, ELVDD and ELVSS will slowly lose power, and then the ELVDD switch circuit and the ELVSS switch circuit inside the driver IC 20 are closed, so that ELVDD and ELVSS are grounded, so that the voltage of ELVDD and ELVSS of the power management IC is instantly powered off to zero.

[0023] In another implementation of this embodiment, when low-power display is used, the system first detects the current power usage, the brightness requirement of the display screen, and the working state of the driver IC. When the set switching conditions are met, the system will tell the power management IC10 and the driver IC20 to transfer power through a control signal, and then turn off the ELVDD and ELVSS outputs of the power management IC10, and simultaneously turn on the corresponding output of the driver IC20. In this way, when the driver IC20 is powered, when ELVDD and ELVSS need to be set to zero, the ELVDD switch circuit and the ELVSS switch circuit can be closed by setting the driver IC20 to ground ELVDD and ELVSS, so that the voltage of ELVDD and ELVSS is instantly powered off to zero.

[0024] In this embodiment, the ELVDD and ELVSS switching circuits 201 and 202 are preferably composed of MOSFET (metal oxide semiconductor field effect transistor) switching elements. On the one hand, the MOSFET switching element has high input impedance and low on-resistance, and has low energy loss during the switching process, which is conducive to reducing the power consumption and heat generation of the device, has high thermal stability, and has a very fast switching speed. On the other hand, the MOSFET switching element is a voltage-controlled device, and the switching action can be achieved by simply changing the gate voltage, without providing a large driving current, so the driving circuit is relatively simple.

[0025] In this embodiment, a filter may be connected to the grounding circuit 203 to reduce the influence of electromagnetic interference, thereby improving the stability and reliability of the system.

[0026] It should be noted that the circuit structure also includes other peripheral circuits, but since the purpose of their configuration is the same or similar to that in the prior art, the present invention does not impose specific limitations on this.

[0027] In summary, the utility model uses two chips to collaboratively control the supply and management of power, and through the design of ELVDD and ELVSS switching circuits, solves the problem that ELVDD and ELVSS power off slowly, causing abnormal power off of AMOLED and inability to clear the screen, and makes the power management IC less equipped with many peripheral components such as MOS tubes, capacitors and resistors, thereby saving costs and reducing occupied space.

[0028] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A circuit structure for improving power failure of AMOLED, characterized in that: The circuit structure includes a first chip, a second chip and an AMOLED display screen, the first chip is electrically connected to the AMOLED display screen, a first pin of the first chip is connected to the AMOLED display screen to output a positive driving voltage ELVDD, a second pin of the first chip is connected to the AMOLED display screen to output a negative driving voltage ELVSS, the second chip includes an ELVDD switching circuit, an ELVSS switching circuit and a grounding circuit, one end of the ELVDD switching circuit of the second chip is connected in series with the first pin of the first chip, one end of the ELVSS switching circuit of the second chip is connected in series with the second pin of the first chip, and the other ends of the ELVDD and ELVSS switching circuits are connected to the grounding circuit.

2. The circuit structure for improving AMOLED power failure according to claim 1, characterized in that: The first chip is a power management IC, which has a built-in boost converter and a buck converter to realize power supply for the AMOLED display.

3. The circuit structure for improving AMOLED power failure according to claim 2, characterized in that: The first chip is configured with a timing controller or a logic circuit to achieve precise control of the output voltage.

4. The circuit structure for improving AMOLED power failure according to claim 3, characterized in that: The first chip is provided with an AVin pin for receiving external power supply.

5. The circuit structure for improving AMOLED power failure according to claim 4, characterized in that: The first pin and the second pin of the first chip are CTRL pins, and the CTRL pins are connected to the boost converter and the buck converter.

6. The circuit structure for improving AMOLED power failure according to claim 5, characterized in that: The second chip is a driver IC, and the driver IC interacts with the power management IC via a communication interface.

7. The circuit structure for improving AMOLED power failure according to claim 6, characterized in that: The second chip includes a voltage detection circuit for detecting the voltage value output by the first chip. When it is detected that the voltage value is lower than a set value, the ELVDD and ELVSS outputs of the first chip are turned off, and the second chip is turned on to supply ELVDD and ELVSS.

8. The circuit structure for improving AMOLED power failure according to claim 7, characterized in that: When ELVDD and ELVSS of the first chip need to be set to zero, the second chip closes the switch circuit when ELVDD and ELVSS are slowly powered down to a set value, thereby grounding ELVDD and ELVSS and instantly powering down to zero.

9. The circuit structure for improving AMOLED power failure according to claim 1, characterized in that: The ELVDD and ELVSS switch circuits are composed of MOSFET (Metal Oxide Semiconductor Field Effect Transistor) switch elements.

10. The circuit structure for improving AMOLED power failure according to claim 1, characterized in that: The grounding circuit is connected to a filter to reduce the influence of electromagnetic interference.

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