Cascade power-on circuit, cascade HDMI device and system

Abstract

The embodiment of the utility model discloses a cascade power-on circuit. According to the technical scheme provided by the embodiment of the invention, the power-on signal interface of the system-on-chip is connected to the CEC signal interface of the cascaded HDMI equipment through the field-effect tube, and after the key of the cascaded HDMI equipment of a local machine is powered on, the key power-on signal can be output to the CEC signal interface through the power-on signal interface, so that other cascaded HDMI equipment is controlled to be powered on, and the power-on of the other cascaded HDMI equipment is improved. And when the system-on-chip is in a standby state, key startup signals of other cascaded HDMI equipment can be received through the CEC signal interface, and then the key startup signals are input into the startup signal interface to control the startup of the cascaded HDMI equipment of the local machine. Therefore, cascade control of the plurality of HDMI devices is realized through the key startup signal of the single HDMI device, key startup operation does not need to be performed on the HDMI devices one by one, the key startup operation of the cascaded HDMI devices is simplified, the startup efficiency is improved, and the operation experience of a user is improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of electronic circuit technology, and in particular to a cascade power-on circuit, a cascade HDMI device and a system. Background Art

[0002] At present, in the application of HDMI (High Definition Multimedia Interface) devices, the HDMI-CEC (Consumer Electronics Control) function is often used to realize the online control of HDMI devices. The HDMI-CEC function allows users to use the remote control to input the CEC signal to the HDMI interface to control the HDMI devices connected to the HDMI interface, realize the cascade control of multiple devices, and improve the efficiency of device control.

[0003] However, for usage scenarios without a remote control, users can only control the power on of a single HDMI device through the power button of the HDMI device, and cannot use the HDMI-CEC function to achieve cascade power-on control. The entire power-on process will be relatively cumbersome and time-consuming, affecting the user experience. Utility Model Content

[0004] The embodiment of the present application provides a cascade power-on circuit, which can perform cascade control of multiple HDMI devices through a button power-on signal of a single HDMI device, thereby improving the power-on efficiency and solving the technical problem that the power-on process of multiple HDMI devices is cumbersome and time-consuming without a remote control.

[0005] In a first aspect, an embodiment of the present application provides a cascade power-on circuit, comprising: a first field effect transistor, a second field effect transistor, a first resistor, and a ceramic capacitor;

[0006] The source of the first field effect tube is connected to the CEC signal interface of the cascaded HDMI device, the gate is connected to one end of the ceramic capacitor, and the drain is connected to the drain of the second field effect tube;

[0007] The source of the second field effect transistor is connected to the power-on signal interface of the system-level chip, the gate is connected to one end of the ceramic capacitor, and the other end of the ceramic capacitor is grounded;

[0008] The power-on signal interface of the system-level chip is set to an input state when the system-level chip is in a standby state, and is used to input a key power-on signal to control the power-on of the local cascaded HDMI device;

[0009] After the local cascaded HDMI device is powered on, the power-on signal interface of the system-level chip is set to an output state for outputting a key-activated power-on signal;

[0010] The gate of the first field effect tube and the gate of the second field effect tube are also connected to the switch control end through the first resistor, so as to control the conduction and disconnection of the first field effect tube and the second field effect tube through the switch control end.

[0011] It can be seen that this application connects the power-on signal interface of the system-level chip to the CEC signal interface of the cascaded HDMI device through the field effect transistor. After the local cascaded HDMI device is powered on by pressing the button, the power-on signal can be output to the CEC signal interface through the power-on signal interface to control the power-on of other cascaded HDMI devices. In addition, when the system-level chip is in standby state, the power-on signal of other cascaded HDMI devices can be received through the CEC signal interface, and then input into the power-on signal interface to control the power-on of the local cascaded HDMI device. In this way, the cascade control of multiple HDMI devices can be realized through the power-on signal of a single HDMI device, without the need to perform the power-on operation of each HDMI device one by one, simplifying the power-on operation of the cascaded HDMI device, improving the power-on efficiency, and thus improving the user's operating experience.

[0012] Furthermore, the cascade power-on circuit also includes a second resistor, and the power-on signal interface of the system-level chip is connected to the source of the second field effect transistor through the second resistor.

[0013] Furthermore, the power-on signal interface is a GPIO interface.

[0014] Furthermore, the key-press power-on signal output by the power-on signal interface of the system-level chip is a 500ms low level. According to the actual level setting of the CEC function control signal, the key-press power-on signal is set to a 500ms low level to distinguish the two level signals, avoid the wrong response of the circuit caused by the confusion of signal recognition, and improve the accuracy of power-on control.

[0015] Furthermore, the cascade startup circuit also includes a third resistor and a fourth resistor, the first resistor is connected to the power input terminal through the third resistor, and is grounded through the fourth resistor.

[0016] Furthermore, the cascade startup circuit also includes a fifth resistor and a sixth resistor, and the source of the second field effect transistor is connected to the power input terminal through the fifth resistor and is grounded through the sixth resistor.

[0017] In a second aspect, an embodiment of the present application provides a cascaded HDMI device, including a CEC signal interface and a cascaded power-on circuit connected to the CEC signal interface;

[0018] The CEC signal interface is used to connect other cascaded HDMI devices, and the cascaded power-on circuit is the cascaded power-on circuit as described in the first aspect.

[0019] Furthermore, the cascaded HDMI device also includes a CEC circuit, one end of which is connected to the CEC signal interface, and the other end of which is connected to the system-level chip, for CEC function control of the cascaded HDMI device.

[0020] Furthermore, the level state of the key power-on signal of the cascade power-on circuit is different from the level state of the CEC function control signal of the CEC circuit.

[0021] By setting the button power-on signal and CEC function control signal in different level states, the cascade power-on circuit and the CEC circuit are isolated from each other, avoiding the control error caused by signal conflict and improving the cascade control accuracy.

[0022] In a third aspect, an embodiment of the present application provides a cascade power-on system, comprising a plurality of cascaded HDMI devices, each of the cascaded HDMI devices being connected via a CEC signal interface, the cascaded HDMI devices comprising a cascaded power-on circuit, and the cascaded power-on circuit is the cascaded power-on circuit as described in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of a cascade power-on circuit structure provided in an embodiment of the present application;

[0024] Figure 2 This is a schematic diagram of cascade power-on control of two devices in an embodiment of the present application;

[0025] Figure 3 It is a structural schematic diagram of a cascaded HDMI device provided in an embodiment of the present application;

[0026] Figure 4 is a schematic diagram of the structure of the CEC circuit in an embodiment of the present application;

[0027] Figure 5 It is a structural diagram of a cascaded HDMI system provided in an embodiment of the present application;

[0028] Figure 6 It is a schematic diagram of cascade power-on control of a cascaded HDMI system in an embodiment of the present application. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the present application clearer, the specific embodiments of the present application are further described in detail in conjunction with the accompanying drawings. It is understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings, not all of the contents. The technical scheme in the embodiments of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present utility model. In the embodiments of the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inside", "outside", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings. These terms are mainly for better describing the present utility model and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation. Moreover, some of the above terms may be used to express other meanings in addition to being used to express orientation or positional relationships. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the present utility model can be understood according to the specific circumstances. In addition, the terms "installation", "setting", "provided with", "connection", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to the specific circumstances. In addition, the terms "first", "second", etc. are mainly used to distinguish different devices, elements, or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, elements, or components. Unless otherwise specified, "multiple" means two or more.

[0030] The cascade power-on circuit provided in the present application is intended to realize cascade control of multiple HDMI devices using a key power-on signal of a single HDMI device, so as to improve the power-on efficiency.

[0031] In the application scenario of HDMI devices, in order to improve the control efficiency between cascaded HDMI devices, the HDMI-CEC function is generally used for online control between cascaded HDMI devices. Among them, CEC, the full name is Consumer Electronics Control, consumer electronics control, CEC simplifies the operation of digital homes, and one remote control can control all digital products that support HDMI. The CEC function brings a lot of convenience to users. It allows end users to use one remote control to control multiple CEC-supported HD devices, thereby eliminating the need to use multiple remote controls to control electronic devices such as televisions (TVs), set-top boxes, and portable HD devices. HDMI is a high-definition multimedia interface that supports various TV and computer video formats, including SDTV and HDTV video images, plus multi-channel digital audio.

[0032] The HDMI-CEC function generally allows users to control devices connected to the HDMI interface through CEC signals, such as single-touch play, system standby, etc. When a user uses a remote control to control a cascaded HDMI device, the HDMI-CEC function can transmit the corresponding CEC control signal to other cascaded HDMI devices, thereby realizing online control of other cascaded HDMI devices.

[0033] Since this control method is only applicable to remote control scenarios, in scenarios without remote control, users can only control the power on of a single HDMI device through the power button of the HDMI device, and cannot use the HDMI-CEC function to achieve cascade power-on control. If you want to control the power on of multiple cascaded HDMI devices, you need to click the power button of each cascaded HDMI device one by one to power on the corresponding device. The entire power-on process will be relatively cumbersome and time-consuming, affecting the user experience.

[0034] Based on this, a cascade power-on circuit of an embodiment of the present application is provided to solve the technical problem that the power-on process of multiple HDMI devices is cumbersome and time-consuming without a remote control. The power-on signal interface of the system-level chip is connected to the CEC signal interface of the cascaded HDMI device through a field effect transistor. After the button of the local cascaded HDMI device is turned on, the button power-on signal can be output to the CEC signal interface through the power-on signal interface to control the power-on of other cascaded HDMI devices. It is also possible to receive the button power-on signal of other cascaded HDMI devices through the CEC signal interface in the standby state of the system-level chip, and then input the power-on signal interface to control the power-on of the local cascaded HDMI device. In this way, cascade control of multiple HDMI devices can be achieved through the button power-on signal of a single HDMI device, without the need to perform the button power-on operation on each HDMI device, simplifying the button power-on operation of the cascaded HDMI device, improving the power-on efficiency, and thus improving the user's operating experience.

[0035] Example:

[0036] Figure 1 A schematic diagram of a cascade power-on circuit provided in the first embodiment of the present application is given. Figure 1 , the cascade power-on circuit specifically includes: a first field effect transistor Q2, a first field effect transistor Q5, a first resistor RH65 and a ceramic capacitor CH27;

[0037] The source of the first field effect transistor Q2 is connected to the CEC signal interface HDMI CEC IO of the cascaded HDMI device, the gate is connected to one end of the ceramic capacitor CH27, and the drain is connected to the drain of the first field effect transistor Q5;

[0038] The source of the first field effect transistor Q5 is connected to the power-on signal interface HDMI CEC PWRON of the system-level chip, the gate is connected to one end of the ceramic capacitor CH27, and the other end of the ceramic capacitor CH27 is grounded;

[0039] The power-on signal interface HDMI CEC PWRON of the system-level chip is set to the input state when the system-level chip is in standby mode, and is used to input the key power-on signal to control the power-on of the cascaded HDMI device of the local machine;

[0040] After the cascaded HDMI device of this machine is powered on, the power-on signal interface of the system-level chip is set to output state to output the key power-on signal;

[0041] The gate of the first field effect transistor Q2 and the gate of the first field effect transistor Q5 are also connected to the switch control terminal CEC PWR EN through the first resistor RH65, so as to control the on and off of the first field effect transistor Q2 and the first field effect transistor Q5 through the switch control terminal CEC PWR EN.

[0042] When the cascade power-on circuit of the embodiment of the present application performs cascade power-on control, the CEC signal interface HDMI CEC IO of the cascaded HDMI device is reused, and the cascade power-on circuit of the local cascaded HDMI device is connected to the cascade power-on circuit of other cascaded HDMI devices by using the CEC signal interface HDMI CEC IO, so as to realize the input or output of the key power-on signal, thereby making the key power-on signal output by the cascade power-on circuit of the local cascaded HDMI device can be transmitted to other cascaded HDMI devices. Similarly, the key power-on signal of other cascaded HDMI devices can also be input into the cascade power-on circuit of the local cascaded HDMI device through the CEC signal interface HDMI CECIO, thereby realizing cascade power-on control.

[0043] It should be noted that, in the embodiment of the present application, each HDMI device includes a corresponding cascade power-on circuit, and each HDMI device is cascaded through its own CEC signal interface to obtain multiple cascaded HDMI devices. Among the multiple cascaded HDMI devices, the local cascaded HDMI device can realize the cascade power-on control of other cascaded HDMI devices through its own cascade power-on circuit.

[0044] Among them, the first field effect transistor Q2 and the first field effect transistor Q5 are used to realize the on and off of the key power-on signal transmission link, which is controlled by the control terminal CEC PWR EN to perform on and off control according to the power-on and power-off requirements of the device. Generally speaking, when the local cascade HDMI device is in standby mode, the control terminal CEC PWR EN controls the first field effect transistor Q2 and the first field effect transistor Q5 to remain in the on state, so that the key power-on signal can be transmitted through the first field effect transistor Q2 and the first field effect transistor Q5 at both ends of the CEC signal interface HDMI CEC IO and the power-on signal interface HDMI CEC PWRON. According to actual needs, after all cascaded HDMI devices are powered on, the first field effect transistor Q2 and the first field effect transistor Q5 can be set to be turned off to prevent the control signal of the CEC circuit from entering the cascade power-on circuit through the CEC signal interface HDMI CEC IO, thereby affecting the operation of the cascade power-on circuit. The first resistor RH65 is a thick film resistor, and its function is to limit the circuit current and protect the circuit safety. The ceramic capacitor CH27 can filter out spikes generated by the first field effect transistor Q2 and the first field effect transistor Q5, providing a filtering effect.

[0045] Exemplarily, assuming that all cascaded devices are currently in standby mode, when the local cascaded HDMI device is not powered on, the power-on signal interface HDMI CEC PWRON is in input mode, and a key power-on signal can be input. When the user triggers the power-on signal through the power-on button of the local cascaded HDMI device, the key power-on signal is input into the system-on chip through the power-on signal interface HDMI CEC PWRON. At this time, the system-on chip responds to the key power-on signal and switches the local cascaded HDMI device to the power-on state. At this time, the first field effect transistor Q2 and the first field effect transistor Q5 are in the on state to transmit the key power-on signal. At this time, the power-on signal interface HDMI CEC PWRON is switched to the output state, and the key power-on signal is output. The key power-on signal is transmitted to the CEC signal interface HDMI CEC IO through the first field effect transistor Q5 and the first field effect transistor Q2, and then the key power-on signal can be output to the cascade power-on circuit of other cascaded HDMI devices through the CEC signal interface HDMI CEC IO to control the power-on of other cascaded HDMI devices.

[0046] like Figure 2As shown, assuming that after device A is powered on, the cascade power-on circuit outputs a key power-on signal to the CEC signal interface HDMI CEC IO, and device B inputs a key power-on signal from the CEC signal interface HDMI CEC IO. At this time, device B is in standby mode, and the power-on signal interface HDMI CEC PWRON of its cascade power-on circuit is set to an input state. Then the cascade power-on circuit of device B transmits the key power-on signal input from the CEC signal interface HDMI CEC IO to the power-on signal interface HDMI CEC PWRON of the cascade power-on circuit of device B through the first field effect transistor Q2 and the first field effect transistor Q5 that are turned on. Since the power-on signal interface HDMI CEC PWRON is in the input state, the key power-on signal can be input to the system-level chip of device B, thereby controlling the power-on of the system-level chip of device B. It can be understood that, assuming that device A is a local cascade HDMI device, and device B is other cascade HDMI devices, device A can realize the cascade power-on control of device B through the cascade power-on circuit of the present application.

[0047] When the user performs power-on control of cascaded HDMI devices, only one of the cascaded HDMI devices needs to be powered on by a button, and the cascaded power-on control can be performed through the cascaded power-on circuits connected to each device. It can be seen that the present application connects the power-on signal interface HDMI CEC PWRON of the system-level chip to the CEC signal interface HDMI CEC IO of the cascaded HDMI device through a field effect tube. After the local cascaded HDMI device is powered on by a button, the power-on signal interface HDMI CEC PWRON can be used to output the power-on signal to the CEC signal interface HDMI CEC IO, thereby controlling the power-on of other cascaded HDMI devices. In addition, the power-on signal of other cascaded HDMI devices can be received through the CEC signal interface HDMI CEC IO in the standby state of the system-level chip, and then the power-on signal interface HDMI CEC PWRON is input to control the power-on of the local cascaded HDMI device. In this way, the cascaded control of multiple HDMI devices can be realized through the power-on signal of a single HDMI device, without the need to perform the power-on operation of each HDMI device one by one, simplifying the power-on operation of the cascaded HDMI device, improving the power-on efficiency, and thus improving the user's operating experience.

[0048] In addition, the present application can adaptively perform power-on control of the device and other cascaded HDMI devices by switching the input and output states of the power-on signal interface HDMI CEC PWRON, and the two functions do not affect each other.

[0049] Optionally, the cascade power-on circuit further includes a second resistor RH73, and the power-on signal interface HDMICEC PWRON of the system-level chip is connected to the source of the first field effect transistor Q5 through the second resistor RH73. By setting the second resistor RH73 between the field effect transistor and the power-on signal interface HDMI CEC PWRON, the second resistor RH73 is a thick film resistor, which can limit the circuit current, protect the circuit safety, and prevent the circuit current from being too large to damage the circuit components.

[0050] Optionally, the power-on signal interface HDMI CEC PWRON is a GPIO (General-purpose input / output) interface. The pins of the GPIO interface can be freely used by the user through program control, and the PIN pins can be used as general-purpose input (GPI) or general-purpose output (GPO) or general-purpose input and output (GPIO) according to practical considerations. Using this feature of the GPIO interface, the system-level chip can adaptively set its input and output status to achieve the input and output effect of the key power-on signal and improve the power-on efficiency.

[0051] Furthermore, the key power-on signal output by the power-on signal interface HDMI CEC PWRON of the system-level chip is a 500ms low level. The present application sets the power-on signal reference to a low level of 500ms to avoid the influence of the CEC signal input by the cascaded HDMI device. It is understandable that, in addition to the cascade power-on circuit, each cascaded HDMI device includes a CEC signal circuit for the implementation of the HDMI-CEC function. Since the cascade power-on circuit reuses the CEC signal interface HDMI CEC IO, the output signal of the cascade power-on circuit may be transmitted to the CEC signal circuit. Similarly, the CEC function control signal of the CEC signal circuit may also affect the cascade power-on circuit. Based on this, it is necessary to set the key power-on signal to a different level from the CEC function control signal. Therefore, the embodiment of the present application sets the key power-on signal to a 500ms low level according to the actual level setting of the CEC function control signal to distinguish the two parts of the level signal, avoid the wrong response of the circuit caused by the confusion of signal recognition, and improve the accuracy of power-on control.

[0052] Optionally, the cascade startup circuit further includes a third resistor RH64 and a fourth resistor RH70, the first resistor RH65 is connected to the power input terminal through the third resistor RH64, and is grounded through the fourth resistor RH70. The cascade startup circuit further includes a fifth resistor RH14 and a sixth resistor RH21, the source of the first field effect transistor Q5 is connected to the power input terminal through the fifth resistor RH14, and is grounded through the sixth resistor RH21. The third resistor RH64, the fourth resistor RH70, the fifth resistor RH14, and the sixth resistor RH21 are all thick film resistors. By correspondingly arranging thick film resistors at the power input terminal and the ground terminal, the corresponding circuit current can be limited, the circuit safety can be protected, and the circuit components can be prevented from being damaged by excessive circuit current.

[0053] Based on the above cascade startup circuit, refer to Figure 3 An embodiment of the present application provides a cascaded HDMI device 10, including a CEC signal interface 12 and a cascaded power-on circuit 11 connected to the CEC signal interface 12; the CEC signal interface 12 is used to connect other cascaded HDMI devices 10, and the cascaded power-on circuit 11 is the cascaded power-on circuit 11 described above.

[0054] The cascade power-on circuit 11 is connected to the CEC signal interface 12 of the cascaded HDMI device 10. After the local cascaded HDMI device is powered on by pressing a button, the cascade power-on circuit 11 can output a button power-on signal to the CEC signal interface 12, thereby controlling other cascaded HDMI devices 10 that are also connected to the CEC signal interface 12 to power on. Similarly, the button power-on signal of other cascaded HDMI devices 10 can also be received through the CEC signal interface 12, thereby controlling the power-on of the local cascaded HDMI device. The cascade control of multiple HDMI devices can be achieved through the button power-on signal of a single HDMI device, without the need to perform the button power-on operation on each HDMI device, simplifying the button power-on operation of the cascaded HDMI device, improving the power-on efficiency, and thereby improving the user's operating experience.

[0055] Optionally, the cascaded HDMI device further includes a CEC circuit 13, referring to Figure 4 One end of the CEC circuit is connected to the CEC signal interface HDMI CEC IO, and the other end is connected to the signal interface HDMI CECA IC of the system-level chip, which is used for cascading the CEC function control of HDMI devices.

[0056] The present application multiplexes the CEC signal interface 12 of the CEC circuit 13 with the cascade power-on circuit 11, and performs signal isolation between the cascade power-on circuit 11 and the CEC circuit 13, so as to simplify the circuit setting. At the same time, when there is a remote control, the CEC function cascade control of the cascaded HDMI device 10 can be performed through the CEC signal interface 12 and the CEC circuit 13; when there is no remote control, the cascade power-on control of the cascaded HDMI device 10 can be performed through the CEC signal interface 12 and the cascade power-on circuit 11, thereby improving the power-on efficiency and the device control effect.

[0057] Optionally, the level state of the key power-on signal of the cascade power-on circuit is different from that of the CEC function control signal of the CEC circuit. For example, the key power-on signal is set to a low level of 500ms, and the CEC function control signal is set to a corresponding high level. Then, the CEC circuit only responds to the high-level input signal, and the cascade power-on circuit only responds to the 500ms low level, thereby achieving signal isolation of the two circuits. By setting the key power-on signal and the CEC function control signal in different level states, the cascade power-on circuit and the CEC circuit are isolated from each other, avoiding the situation where control errors caused by signal conflicts, and improving the cascade control accuracy.

[0058] Based on the above embodiments, Figure 5 The embodiment of the present application further provides a cascade power-on system, including a plurality of cascaded HDMI devices 10, each of which is connected via a CEC signal interface 12, and the cascaded HDMI devices 10 include a cascade power-on circuit 11, which is the cascade power-on circuit 11 described above. In addition, the cascaded HDMI devices 10 also include a CEC circuit 13, which is the CEC circuit 13 described above.

[0059] For example, refer to Figure 6 , a schematic diagram of cascade power-on control of the cascade power-on system of an embodiment of the present application is provided. Assuming that all four devices are in standby mode, the user controls the power-on of one device through the power-on button, and uses the cascade power-on system to perform cascade power-on control of other cascaded HDMI devices. The device that the user turns on by pressing the button is defined as the host, and the remaining devices are defined as slaves. When the host receives the power-on button, it notifies the host PC through the serial port to output a power-on signal to the three slaves. The three slaves automatically turn on after receiving the signal from the CEC signal interface, thereby realizing the cascade power-on control of the cascade power-on system.

[0060] The above are only preferred embodiments of the present application and the technical principles used. The present application is not limited to the specific embodiments described herein, and various obvious changes, readjustments and substitutions that can be made by those skilled in the art will not deviate from the scope of protection of the present application. Therefore, although the present application is described in more detail through the above embodiments, the present application is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the claims.

Claims

1. A cascade power-on circuit, characterized in that: include: A first field effect transistor, a second field effect transistor, a first resistor and a ceramic capacitor; The source of the first field effect tube is connected to the CEC signal interface of the cascaded HDMI device, the gate is connected to one end of the ceramic capacitor, and the drain is connected to the drain of the second field effect tube; The source of the second field effect transistor is connected to the power-on signal interface of the system-level chip, the gate is connected to one end of the ceramic capacitor, and the other end of the ceramic capacitor is grounded; The power-on signal interface of the system-level chip is set to an input state when the system-level chip is in a standby state, and is used to input a key power-on signal to control the power-on of the local cascaded HDMI device; After the local cascaded HDMI device is powered on, the power-on signal interface of the system-level chip is set to an output state for outputting a key-activated power-on signal; The gate of the first field effect tube and the gate of the second field effect tube are also connected to the switch control end through the first resistor, so as to control the conduction and disconnection of the first field effect tube and the second field effect tube through the switch control end.

2. The cascade startup circuit according to claim 1, characterized in that: A second resistor is also included, and the power-on signal interface of the system-level chip is connected to the source of the second field effect transistor through the second resistor.

3. The cascade startup circuit according to claim 1, characterized in that: The power-on signal interface is a GPIO interface.

4. The cascade startup circuit according to claim 1, characterized in that: The key-press power-on signal output by the power-on signal interface of the system-level chip is a low level signal for 500ms.

5. The cascade startup circuit according to claim 1, characterized in that: It also includes a third resistor and a fourth resistor, the first resistor is connected to the power input terminal through the third resistor, and is grounded through the fourth resistor.

6. The cascade startup circuit according to claim 1, characterized in that: It also includes a fifth resistor and a sixth resistor, and the source of the second field effect tube is connected to the power input terminal through the fifth resistor and is grounded through the sixth resistor.

7. A cascaded HDMI device, characterized in that: It includes a CEC signal interface and a cascade power-on circuit connected to the CEC signal interface; The CEC signal interface is used to connect other cascaded HDMI devices, and the cascaded power-on circuit is the cascaded power-on circuit as described in any one of claims 1-6.

8. The cascaded HDMI device according to claim 7, characterized in that: It also includes a CEC circuit, one end of which is connected to the CEC signal interface, and the other end of which is connected to the system-level chip, for CEC function control of cascaded HDMI devices.

9. The cascaded HDMI device according to claim 8, characterized in that: The level state of the key power-on signal of the cascade power-on circuit is different from the level state of the CEC function control signal of the CEC circuit.

10. A cascade startup system, characterized in that: The invention comprises a plurality of cascaded HDMI devices, each of the cascaded HDMI devices is connected via a CEC signal interface, the cascaded HDMI devices comprises a cascaded power-on circuit, and the cascaded power-on circuit is the cascaded power-on circuit as claimed in any one of claims 1 to 6.

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