CN111404562A - Method for electrostatic discharge protection of a receiver, and receiver - Google Patents

Abstract

The invention provides a method for electrostatic discharge protection of a receiver and a related receiver. The receiver may include a reference voltage terminal, a detection terminal, at least one set of receiving terminals, and at least one set of termination resistors. The method may comprise: generating a detection result according to the voltage level of the detection terminal; and controlling whether to couple the at least one set of termination resistors between the at least one set of receiving terminals and the reference voltage terminal, respectively, according to the detection result.

Description

Method for electrostatic discharge protection of receiver, and receiver

technical field

The present invention relates to electrostatic discharge protection, and more particularly, to a method for electrostatic discharge protection of a receiver, and related receivers.

Background technique

With the use of various home multimedia devices such as set-top boxes (set-top boxes) and multimedia players and amplifiers, audio and video data can be input through a High Definition Multimedia Interface (HDMI). Since the user may frequently plug/unplug the high-definition multimedia interface cable, the chances of the high-definition multimedia interface terminal being damaged by electrostatic discharge (ESD) are greatly increased.

Electrostatic discharge is one of the major causes of damage to most electronic devices or electronic systems. For example, at the moment when the cable is inserted into the high-definition multimedia interface, the static electricity accumulated on the cable may instantly discharge the high-definition multimedia interface and cause damage to its internal circuit. In particular, this damage is usually permanent. The damage of nature often affects the overall circuit function. In order to avoid the above problems, the related art usually utilizes an additional electrostatic discharge protection circuit to improve the tolerance to electrostatic discharge. However, the related art method not only adds extra cost, but also the tolerance to electrostatic discharge is generally limited by the specifications of the protective element itself. Therefore, there is a need for a novel method and related architecture to improve ESD tolerance.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a method for electrostatic discharge protection of a receiver, and a related receiver, so as to improve the resistance of the receiver to electrostatic discharge.

At least one embodiment of the present invention provides an electrostatic discharge protection method for a receiver, wherein the receiver may include a reference voltage terminal, a detection terminal, at least one set of receiving terminals, and at least one set of terminating resistors, and the The method includes: generating a detection result according to the voltage level of the detection terminal; and controlling whether the at least one group of terminal resistors is respectively coupled between the at least one group of receiving terminals and the reference voltage terminal according to the detection result.

At least one embodiment of the present invention provides a receiver, wherein the receiver may include a reference voltage terminal, a detection circuit, at least one set of receiving terminals, at least one set of terminating resistors, and at least one set of switching circuits. The reference voltage terminal can be used to supply power to the receiver, and the at least one group of receiving terminals can be used to receive data. The detection circuit is coupled to a detection terminal in the receiver, wherein the detection circuit can be used to generate a detection result according to the voltage level of the detection terminal. The at least one set of switching circuits is coupled to the at least one set of terminating resistors, wherein the at least one set of switching circuits can control whether the at least one set of terminating resistors are respectively coupled to the at least one set of receiving terminals and the reference according to the detection result. between the voltage terminals.

The method and related device proposed by the present invention, such as the receiver, can determine whether the receiver has been connected to a transmitter through a cable according to the detection result obtained by detecting the voltage level of the detection terminal, so as to control whether the receiver is connected to a transmitter through a cable. The at least one set of termination resistors are respectively coupled between the at least one set of receiving terminals and the reference voltage terminal to avoid damage to the receiver due to electrostatic discharge when the receiver is not connected.

Description of drawings

FIG. 1 is a schematic diagram of a receiver according to an embodiment of the present invention.

FIG. 2 is an example in which the receiver has not yet been connected to a transmitter through a cable according to an embodiment of the present invention.

FIG. 3 is an example in which the receiver has been connected with the transmitter through the cable according to an embodiment of the present invention.

FIG. 4 is a flowchart of a method for ESD protection according to an embodiment of the present invention.

Symbol Description

10 HDMI Receivers

20 HDMI Transmitter

50 cables

100 detection circuit

110_1, 110_2, 110_3 circuit units

200 differential signal generator

AV _CC reference voltage terminal

R _T1 , R _T2 resistance

SW ₁ , SW ₂ switch circuit

T _C,TX , T _C,RX , T _D,TX , T _D,RX terminals

T1 _,RX , T2 _,RX receiving terminal

T1 _,TX , T2 _,TX transmission terminal

410, 420, 430, 440 steps

Detailed ways

1 is a schematic diagram of a receiver such as a high-definition multimedia interface receiver (abbreviated as HDMI receiver) 10 according to an embodiment of the present invention. As shown in FIG. 1 , the HDMI receiver 10 may include a reference voltage terminal AV _CC , a detection circuit 100 , at least one group of receiving terminals such as receiving terminals T _1,RX and T _2,RX , at least one group of terminating resistors such as resistor R _T1 and R _T2 , and at least one set of switching circuits such as switching circuits SW ₁ and SW ₂ . The receiving terminals T1 _{, RX} and T2 _{, RX} may include at least one group of Transition Minimized Differential Signaling (TMDS) channels for receiving data (eg, video and audio data), and the reference voltage terminal AV _CC may be used for supplying Power is supplied to one or more circuit units such as circuit units 110_1 , 110_2 , and 110_3 inside the HDMI receiver 10 , wherein the circuit units 110_1 , 110_2 , and 110_3 may be regarded as related processing circuits for receiving data (eg, audio and video data). In this embodiment, the detection circuit 100 can be coupled to a detection terminal of the HDMI receiver 10 such as a terminal T _{D, RX} (for example, a 5V power receiving terminal) and a confirmation terminal such as a terminal T _{C, RX} (for example, a hot plug (hot plug detect terminal), and the terminal TC _{, RX} can be further coupled to the above at least one group of switching circuits such as switch circuits SW ₁ and SW ₂ , wherein the detection circuit 100 can be based on the voltage of the terminals _{TD, RX} . A detection result is generated at the level, and the detection result is transmitted or output through the terminals TC _{, RX} . For example, the voltage level of the detection terminal such as the terminal T _{D, RX} can be regarded as a detection voltage, which may vary between the voltage levels V1 and V2, for example: V1=0V, V2=5V, but the present invention Not limited to this. In addition, the at least one set of switching circuits can control whether to couple the resistors RT1 and RT2 between the receiving terminals _{T1 , RX} and _{T2 , RX} and the reference voltage terminal AV _CC , respectively, according to the detection result. For example, the switch circuit SW1 can be coupled between the resistor _RT1 and the receiving terminals _{T1 , RX} , and the switch circuit SW2 can be coupled between the resistor _RT2 and the receiving terminals _{T2 , RX} , wherein the switch circuit SW ₁ and SW ₂ can be controlled to be turned on according to the detection result; for another example, the switch circuit SW ₁ can be coupled between the resistor R _T1 and the reference voltage terminal AV _CC , and the switch circuit SW ₂ can be coupled to the resistor R Between _T2 and the reference voltage terminal AV _CC , the switch circuits SW ₁ and SW ₂ can be controlled to be turned on according to the detection result, but the invention is not limited to this. All the various implementations that control whether the resistors RT1 and RT2 are respectively coupled between the receiving terminals _{T1 , RX} and _{T2 , RX} and the reference voltage terminal AV _CC according to the detection result belong to the present invention. range.

2 is an example in which the HDMI receiver 10 has not yet been connected to a transmitter such as a high-definition multimedia interface transmitter (referred to as HDMI transmitter) 20 through a cable 50 according to an embodiment of the present invention. The HDMI transmitter 20 may include at least one set of differential signal generators, such as the differential signal generator 200, to generate differential output signals according to the differential image data. In this embodiment, since the HDMI receiver 10 has not been connected to the HDMI transmitter 20 through a cable 50, a voltage level on the terminals _{TD and TX} of the HDMI transmitter 20 (for example, a 5V power transmission terminal) (eg 5V) the voltage level of the terminal _{TD, RX} of the HDMI receiver 10 cannot be pulled up to a certain level (eg 5V) through the cable 50, therefore, the voltage level of the terminal _{TD, RX} may be lower than The specific level, or, has not been stably maintained at the specific level. At this time, the detection circuit 100 generates a first detection result at the terminals TC _{, RX} to indicate that the connection has not been completed (eg, a logic low signal), wherein the first detection result can be used as an example of the detection result. Based on the first detection result, the HDMI receiver ₁₀ may control the switch circuits SW1 and SW2 ₍ eg, by keeping the switch circuits SW1 and SW2 closed by the detection circuit _{100 )} , so that the switch circuits SW1 and _SW2 are in their non _- conductive state. In a non-conductive state, the static electricity accumulated by the cable 50 will not be discharged at the moment of contacting the receiving terminals T1 _{, RX} and/or T2 _{, RX} to cause damage to the circuit units 110_1, 110_2, 110_3. In addition, since the connection has not been completed, the terminals TC _{, TX} of the HDMI transmitter 20 (eg, a hot-plug detection terminal) may receive a signal (eg, the logic low signal) corresponding to the unfinished connection through the cable 50, Or, if the signal corresponding to connection completion (eg, a logic high signal) cannot be received, the HDMI transmitter 20 (such as the differential signal generator 200 therein) will not start to transmit audio and video data.

FIG. 3 is an example in which the HDMI receiver 10 has been connected to the HDMI transmitter 20 through the cable 50 according to an embodiment of the present invention. In this embodiment, since the HDMI receiver 10 has been connected with the HDMI transmitter 20 through the cable 50, the voltage level (eg 5V) on the terminals _{TD and TX} of the HDMI transmitter 20 can pass through the cable 50. The voltage level of the terminal _{TD, RX} of the HDMI receiver 10 is pulled up to the specific level (eg, 5V), so the voltage level of the terminal _{TD, RX} can be stably maintained at the specific level. At this time, the detection circuit 100 will generate a second detection result at the terminals TC _{, RX} to indicate that the connection has been completed (eg, the logic high signal), wherein the second detection result can be used as another example of the detection result. Based on the second detection result, the HDMI receiver 10 may control the switch circuits SW ₁ and SW ₂ (eg, by turning on the switch circuits SW ₁ and SW ₂ by the detection circuit 100 ), so that the switch circuits SW ₁ and SW ₂ are switched to their conduction In the on state, that is, at this time, the resistors RT1 and RT2 can be respectively coupled between the receiving terminals _{T1 , RX} and _{T2 , RX} and the reference voltage terminal AV _CC . In addition, since this connection has been completed, the terminals TC _{, TX} of the HDMI transmitter 20 can receive a signal corresponding to the completion of the connection (eg, the logic high signal) through the cable 50, and the HDMI transmitter 20 (such as the differential signal in which the differential signal is generated) The device 200) can start the transmission of audio and video data through the transmission terminals T1 _{, TX} and T2 _{, TX} .

FIG. 4 is a flowchart of a method for ESD protection according to an embodiment of the present invention.

In step 410, the detection circuit 100 may generate a detection result (such as the above-mentioned detection result, eg, the first detection result or the second detection result) according to the voltage level of a detection terminal (eg, terminal T _D,RX ).

In step 420, when the detection result indicates that the voltage level of the detection terminal (eg, terminal T _{D, RX} ) is lower than a specific level (such as the above-mentioned specific level, for example, 5V), enter step 430; otherwise, enter Step 440.

In step 430, the switch circuits SW1 and SW2 can avoid coupling the resistors _RT1 and _RT2 between the receiving terminals _{T1 , RX} and _{T2 , RX} respectively and the reference voltage terminal AV _CC , for example, a switch _The circuits SW1 and SW2 are not turned _on .

In step 440, the switch circuits SW1 and SW2 can respectively couple the resistors _RT1 and _RT2 between the receiving terminals _{T1 , RX} and _{T2 , RX} and the reference voltage terminal AV _CC , for example, the switch circuits SW ₁ and SW ₂ can be turned on.

In addition, for the sake of brevity, the above-described embodiments only use a set of receiving terminals (such as receiving terminals _{T1 ,RX} and _{T2 ,RX} ), a set of terminating resistors (such as resistors RT1 and RT2), and a set of switching circuits (such as The switch circuits SW ₁ and SW ₂ ) are described as examples, but the present invention is not limited thereto. For example, the HDMI receiver 10 may include multiple groups of receiving terminals and corresponding terminating resistors and switching circuits. The method proposed in the present invention can also be analogized to each group of receiving terminals in the HDMI receiver 10 and the corresponding terminating resistors and switching circuits. switch circuit.

In conclusion, the method and related apparatus (eg, HDMI receiver 10 ) proposed by the present invention can avoid relatively fragile circuit elements such as circuit elements inside the HDMI receiver 10 with no or less likely side effects. 110_1, 110_2, 110_3 are damaged by electrostatic discharge. For example, at the moment when the cable 50 touches the receiving terminals T1 _{, RX} and/or T2 _{, RX} , since the voltage level of the terminals T _{D, RX} has not been pulled to the specific level, the switch circuit SW ₁ And SW ₂ will not be turned on, the static electricity accumulated on the cable 50 will be discharged through other paths with relatively high electrostatic discharge tolerance and will not enter the interior of the HDMI receiver 10 through the terminal resistance and cause the circuit units 110_1 and 110_2 , 110_3, damage.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the claims of the present invention shall fall within the scope of the present invention.

Claims (10)

1. A method for electrostatic discharge protection for a receiver, wherein the receiver comprises a reference voltage terminal, a detection terminal, at least one set of receiving terminals, and at least one set of terminating resistors, and the method comprises: generating a detection result according to the voltage level of the detection terminal; and Whether to couple the at least one group of terminal resistors between the at least one group of receiving terminals and the reference voltage terminal is controlled according to the detection result. 2. The method of claim 1, wherein when the receiver has not been connected to a transmitter through a cable, the voltage level of the detection terminal is lower than a specific level, and controls whether to connect the at least The step of respectively coupling a set of terminal resistors between the at least one set of receiving terminals and the reference voltage terminal includes: When the detection result indicates that the voltage level of the detection terminal is lower than the specific level, it is avoided to respectively couple the at least one group of terminal resistors between the at least one group of receiving terminals and the reference voltage terminal. 3. The method of claim 1, wherein when the receiver is connected to a transmitter through a cable, the transmitter pulls the voltage level of the detection terminal to a specific level through the cable, And the step of controlling whether to couple the at least one group of terminal resistors between the at least one group of receiving terminals and the reference voltage terminal respectively includes: When the detection result indicates that the voltage level of the detection terminal has been pulled to the specific level, the at least one group of terminal resistors are respectively coupled between the at least one group of receiving terminals and the reference voltage terminal. 4. The method of claim 1, wherein the receiver is a high-definition multimedia interface receiver. 5. The method of claim 4, wherein the at least one set of receive terminals comprises at least one set of transmission-minimized differential signal paths. 6. A receiver comprising: a reference voltage terminal for supplying power to the receiver; a detection circuit, coupled to a detection terminal in the receiver, for generating a detection result according to the voltage level of the detection terminal; At least one set of receiving terminals for receiving data; at least one set of terminating resistors; and at least one set of switching circuits coupled to the at least one set of terminal resistors, wherein the at least one set of switching circuits controls whether to couple the at least one set of terminal resistors to the at least one set of receiving terminals respectively according to the detection result and the reference voltage terminal. 7. The receiver of claim 6, wherein: The voltage level of the detection terminal is lower than a certain level when the receiver has not been connected to a transmitter through a cable; and When the receiver is connected to a transmitter through a cable, the transmitter pulls the voltage level of the detection terminal to a specific level through the cable. 8. The receiver of claim 7, wherein: When the detection result indicates that the voltage level of the detection terminal is lower than the specific level, the at least one switching circuit avoids coupling the at least one set of terminal resistors to the at least one set of receiving terminals and the reference voltage terminal respectively between; and When the detection result indicates that the voltage level of the detection terminal has been pulled to the specific level, the at least one switching circuit couples the at least one set of terminal resistors to the at least one set of receiving terminals and the reference voltage respectively between the terminals. 9. The receiver of claim 6, wherein the receiver is a high-definition multimedia interface receiver. 10. The receiver of claim 9, wherein the at least one set of receive terminals includes at least one set of transmission-minimized differential signal paths.

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