HDMI CEC leakage current protection circuit and device

Abstract

The utility model relates to the technical field of circuit protection, and discloses an HDMI CEC leakage current protection circuit and equipment, the HDMI CEC leakage current protection circuit is connected with an MOS switch, a first power supply resistor, a second power supply resistor and a third power supply resistor, a drain electrode of the MOS switch is electrically connected with a CEC of an HDMI, and a grid electrode of the MOS switch is electrically connected with the second power supply resistor and a CEC of an HDMI receiving end; the first power supply resistor and the third power supply resistor are used for carrying out voltage division processing on power supply voltage, driving voltage is provided for the base electrode of the MOS switch, when the HDMI is powered on, the MOS switch is switched on, a CEC signal is transmitted from the drain electrode to the grid electrode, when the HDMI is powered off, the MOS switch is switched off, the CEC signal cannot be transmitted, and the leakage current is zero, the circuit effectively controls the CEC leakage current when the HDMI is powered off, power consumption is reduced, and the service life of the circuit is prolonged. And meanwhile, the circuit design is simple, the reliability is high, and the problem that the service life of the HDMI equipment is abraded due to leakage current when the HDMI equipment is in a standby state in the prior art is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of circuit protection, and particularly relates to an HDMI CEC leakage current protection circuit and device. Background Technique

[0002] HDMI (High-Definition Multimedia Interface) is an interface standard widely used in consumer electronic devices, which allows audio and video signals to be transmitted through a single cable. HDMI CEC (Consumer Electronics Control) is a protocol for communication between devices connected via HDMI, allowing users to control multiple devices, such as TVs, Blu-ray players, audio systems, etc., with a single remote control.

[0003] When an HDMI device is in standby mode, even if the device is in the off state, leakage current will be generated, which will cause wear and tear on the service life of the device. Summary of the Utility Model

[0004] The purpose of the utility model is to provide an HDMI CEC leakage current protection circuit and device, aiming to solve the problem that the leakage current of HDMI devices in standby mode in the prior art will cause wear and tear on the device life.

[0005] The utility model is implemented as follows. In the first aspect, the utility model provides an HDMI CEC leakage current protection circuit, including:

[0006] A MOS switch, a first power supply resistor, a second power supply resistor, and a third power supply resistor;

[0007] The MOS switch has a base, a drain, and a gate;

[0008] The drain of the MOS switch is electrically connected to the CEC of HDMI to realize the network connection between the MOS switch and HDMI, and the HCMI transmits a CEC signal to the MOS switch through the network connection with the MOS switch;

[0009] The first power supply resistor is electrically connected to the power supply, the base of the MOS switch, and the third power supply resistor respectively. The third power supply resistor is electrically connected to the first power supply resistor, the base of the MOS switch, and the ground wire respectively. The first power supply resistor and the second power supply resistor are used to perform voltage division processing on the power supply voltage output by the power supply to provide a drive voltage after voltage division processing for the base of the MOS switch;

[0010] The second power supply resistor is electrically connected to the sum of the gates of the MOS switches and the CEC of the HDMI receiving end respectively. The second power supply resistor is used to pull up the CEC signal of the HDMI to enhance the driving current of the CEC signal;

[0011] When the HDMI is in the powered-on state, the MOS switch is in the conducting state. The HDMI transmits the CEC signal to the drain of the MOS switch, and the CEC signal is transmitted from the drain of the MOS switch to the gate;

[0012] When the HDMI is in the powered-off state, the power supply cancels the output of the supply voltage, and the base of the MOS switch does not receive the driving voltage. At this time, the MOS switch is in the cut-off state, and the CEC signal cannot be transmitted from the drain of the MOS switch to the gate, making the leakage current of the CEC zero.

[0013] In a second aspect, the present invention provides an HDMI CEC leakage current protection device, and the device adopts an HDMI CEC leakage current protection circuit according to any one of the first aspect.

[0014] The present invention provides an HDMI CEC leakage current protection circuit, which has the following beneficial effects:

[0015] The present invention connects the MOS switch, the first power supply resistor, the second power supply resistor and the third power supply resistor, electrically connects the drain of the MOS switch to the CEC of the HDMI, and electrically connects the gate to the second power supply resistor and the CEC of the HDMI receiving end. The supply voltage is divided by the first power supply resistor and the third power supply resistor to provide a driving voltage to the base of the MOS switch. When the HDMI is powered on, the MOS switch is turned on, and the CEC signal is transmitted from the drain to the gate. When the HDMI is powered off, the MOS switch is turned off, the CEC signal cannot be transmitted, and the leakage current is zero. This circuit effectively controls the CEC leakage current when the HDMI is powered off, reduces power consumption, ensures the complete transmission of the signal, and at the same time has a simple circuit design and high reliability, solving the problem that the leakage current of HDMI devices during standby in the prior art will cause wear and tear on the device life. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a step schematic diagram of an HDMI CEC leakage current protection circuit provided by an embodiment of the present invention.

[0017] Reference numerals: 1 - gate, 2 - base, 3 - drain, RH1 - first power supply resistor, RH2 - second power supply resistor, RH3 - third power supply resistor, VDDAO - analog output power supply. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] In order to make the objectives, technical solutions and advantages of the present utility model more clear and understandable, the present utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0019] The implementation of the present utility model will be described in detail below in conjunction with specific embodiments.

[0020] Referring to Figure 1 as shown, a preferred embodiment is provided for the present utility model.

[0021] In a first aspect, the present utility model provides an HDMI CEC leakage current protection circuit, including:

[0022] a MOS switch, a first power supply resistor, a second power supply resistor, and a third power supply resistor.

[0023] Specifically, the MOS switch has a base, a drain, and a gate. The MOS switch generally refers to a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). In a circuit, it is mainly used as a switch, and its working states are mainly two: the conducting state and the cut-off state. The base is used for current inflow, the drain is used for current outflow, and the gate is used for controlling the current between the base and the gate by applying a voltage.

[0024] More specifically, HDMI (High-Definition Multimedia Interface) is an interface standard for transmitting high-quality audio and video signals, and CEC (Consumer Electronics Control) is a part of the HDMI standard, which is used to realize the interoperability function between multiple HDMI devices through a single control line.

[0025] More specifically, the drain of the MOS switch is electrically connected to the CEC of the HDMI to realize the network connection between the MOS switch and the HDMI. The HCMI transmits the CEC signal to the MOS switch through the network connection with the MOS switch.

[0026] More specifically, the first power supply resistor is electrically connected to the power supply, the base of the MOS switch, and the third power supply resistor respectively. The third power supply resistor is electrically connected to the first power supply resistor, the base of the MOS switch, and the ground wire respectively. The first power supply resistor and the second power supply resistor are used to divide the power supply voltage output by the power supply to provide a divided driving voltage for the base of the MOS switch.

[0027] More specifically, the second power supply resistor is electrically connected to the analog output power supply, the gate of the MOS switch, and the CEC of the HDMI receiver respectively. The second power supply resistor is used to pull up the CEC signal of HDMI to enhance the driving current of the CEC signal. The purpose is to enhance the driving current of the CEC signal, thereby providing compatibility and stability.

[0028] It can be understood that the circulation of the CEC signal of HDMI can be regarded as two segments. The first segment is that the CEC signal of HDMI is transmitted to the MOS switch through the drain, and it receives interference from the base of the MOS switch when passing through the MOS switch. The second segment is that the CEC signal after interference is transmitted to the interference of the second power supply resistor and then transmitted to the HDMI receiver after receiving the interference.

[0029] It should be noted that in the traditional circuit, HDMI is directly electrically connected to the HDMI receiver, and the electrical signal sent by HDMI is directly transmitted to the HDMI receiver, so as to realize the control of the HDMI receiver by HDMI. And this solution is to add a leakage protection circuit between HDMI and HDMI.

[0030] More specifically, HDMI has two states, namely the powered-on state and the powered-off state. When HDMI is in the powered-on state, the MOS switch is in the conducting state, and HDMI transmits the CEC signal to the drain of the MOS switch, and the CEC signal is transmitted from the drain of the MOS switch to the gate.

[0031] More specifically, when HDMI is in the powered-off state, the power supply cancels the output of the supply voltage, and the base of the MOS switch does not receive the driving voltage. At this time, the MOS switch is in the cut-off state, and the CEC signal cannot be transmitted from the drain of the MOS switch to the gate, making the leakage current of CEC zero.

[0032] It can be understood that by setting a leakage protection circuit described in this technical solution between HDMI and the HDMI receiver, the leakage current of HDMI to the HDMI receiver can be avoided when HDMI is in the powered-off state, thus achieving more perfect protection.

[0033] The utility model provides an HDMI CEC leakage current protection circuit, which has the following beneficial effects:

[0034] The utility model connects a MOS switch, a first power supply resistor, a second power supply resistor and a third power supply resistor, electrically connects the drain of the MOS switch to the CEC of HDMI, electrically connects the gate to the CEC of the second power supply resistor and the HDMI receiving end, divides the supply voltage through the first power supply resistor and the third power supply resistor, provides a driving voltage to the base of the MOS switch. When HDMI is powered on, the MOS switch is turned on, and the CEC signal is transmitted from the drain to the gate. When HDMI is powered off, the MOS switch is turned off, the CEC signal cannot be transmitted, and the leakage current is zero. This circuit effectively controls the CEC leakage current when HDMI is powered off, reduces power consumption, ensures the complete transmission of signals. At the same time, the circuit design is simple and the reliability is high, solving the problem that the leakage current of HDMI devices during standby in the prior art will cause wear and tear on the device life.

[0035] Preferably, the first power supply resistor and the third power supply resistor have the same voltage value of the applicable supply voltage.

[0036] Specifically, the power supply resistor is a form of description of the resistance specification. The power supply resistor usually adopts the form of XV power supply resistor, where X represents the resistance value of the supply voltage applicable to the power supply resistor, that is, the power supply resistor can work in an environment with a supply voltage corresponding to this value.

[0037] Preferably, the voltage value of the supply voltage provided by the power supply is the same as the voltage value of the applicable supply voltage of the first power supply resistor and the third power supply resistor.

[0038] Specifically, the first power supply resistor and the third power supply resistor are used to jointly divide the supply voltage provided by the power supply to obtain the driving voltage after voltage division processing. Therefore, the supply voltage value of the supply voltage should be the same as the voltage value of the applicable supply voltage of the first power supply resistor and the second power supply resistor.

[0039] Preferably, the voltage value of the applicable supply voltage of the first power supply resistor and the third power supply resistor is 12V.

[0040] Preferably, the voltage value of the applicable supply voltage of the second power supply resistor is 3.3V.

[0041] Preferably, the voltage value of the supply voltage of the analog output power supply is the same as the voltage value of the applicable supply voltage of the second power supply resistor.

[0042] Preferably, the supply voltage of the power supply is 12V.

[0043] In the second aspect, the utility model provides an HDMI CEC leakage current protection device, and the device adopts an HDMI CEC leakage current protection circuit according to any one of the first aspect.

[0044] In this embodiment, for the specific implementation of each module in the above device embodiment, please refer to the description in the above circuit embodiment, and details will not be repeated here.

[0045] The foregoing are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An HDMI CEC leakage current protection circuit, characterized in that Including: A MOS switch, a first power supply resistor, a second power supply resistor, and a third power supply resistor; The MOS switch has a base, a drain, and a gate; The drain of the MOS switch is electrically connected to the CEC of the HDMI to achieve a network connection between the MOS switch and the HDMI. The HDMI transmits a CEC signal to the MOS switch through the network connection with the MOS switch; The first power supply resistor is electrically connected to a power supply, the base of the MOS switch, and the third power supply resistor respectively. The third power supply resistor is electrically connected to the first power supply resistor, the base of the MOS switch, and the ground wire respectively. The first power supply resistor and the second power supply resistor are used to divide the power supply voltage output by the power supply to provide a divided driving voltage for the base of the MOS switch; The second power supply resistor is electrically connected to an analog output power supply, the gate of the MOS switch, and the CEC of the HDMI receiving end. The second power supply resistor is used to pull up the CEC signal of the HDMI to enhance the driving current of the CEC signal; When the HDMI is in the powered-on state, the MOS switch is in the conducting state. The HDMI transmits a CEC signal to the drain of the MOS switch, and the CEC signal is transmitted from the drain of the MOS switch to the gate; When the HDMI is in the powered-off state, the power supply cancels the output of the power supply voltage, and the base of the MOS switch does not receive the driving voltage. At this time, the MOS switch is in the cut-off state, and the CEC signal cannot be transmitted from the drain of the MOS switch to the gate, making the leakage current of the CEC zero; 2. The HDMI CEC leakage current protection circuit according to claim 1, wherein The first power supply resistor and the third power supply resistor have the same voltage value of the applicable power supply voltage; 3. The HDMI CEC leakage current protection circuit according to claim 2, wherein The voltage value of the power supply voltage provided by the power supply is the same as the voltage value of the applicable power supply voltage of the first power supply resistor and the third power supply resistor; 4. The HDMI CEC leakage current protection circuit according to claim 2, wherein The voltage value of the applicable power supply voltage of the first power supply resistor and the third power supply resistor is 12V; 5. The HDMI CEC leakage current protection circuit according to claim 1, wherein The voltage value of the applicable power supply voltage of the second power supply resistor is 3.3V; 6. The HDMI CEC leakage current protection circuit according to claim 5, wherein, The voltage value of the power supply voltage of the analog output power supply is the same as the voltage value of the applicable power supply voltage of the second power supply resistor; 7. The HDMI CEC leakage current protection circuit according to claim 1, wherein The power supply voltage of the power supply is 12V; 8. An HDMI CEC leakage current protection device, characterized in that, The device adopts an HDMI CEC leakage current protection circuit according to any one of claims 1-7.

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