Cable

Abstract

A cable (1) is provided with a first re-timer (10a), a second re-timer (10b), and a coaxial line (20), and the first re-timer (10a) and the second re-timer (10b) each have a differential single-ended conversion unit (11) to which a differential signal is inputted and which outputs a single-ended signal, and a single-ended differential conversion unit (12) to which a single-ended signal is inputted and which outputs a differential signal. The first retimer (10a) and the second retimer (10b) are connected via a coaxial line (20).

Description

Technical Field

[0001] The present disclosure relates to cables. Background Art

[0002] Patent Document 1 discloses a technology for reducing the number of electric wires by utilizing a ground shield of a coaxial line or an STP line as a signal line for low-speed communication.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: U.S. Patent No. 9076575 Summary of the invention

[0006] Problems to be solved by the invention

[0007] According to the technique disclosed in Patent Document 1, the number of electric wires excluding the ground shield can be reduced to two, but it is desired to further reduce the number of electric wires.

[0008] Therefore, the present disclosure provides a cable capable of reducing the number of electric wires.

[0009] Means used to solve problems

[0010] The cable disclosed in the present invention comprises a first conversion unit, a second conversion unit and a coaxial line. The first conversion unit and the second conversion unit respectively have a differential-single-ended conversion unit that receives an input differential signal and outputs a single-ended signal, and a single-ended-differential conversion unit that receives an input single-ended signal and outputs a differential signal. The first conversion unit and the second conversion unit are connected via the coaxial line.

[0011] In addition, these general or specific embodiments may be implemented by systems, methods, integrated circuits, computer programs, or computer-readable recording media such as CD-ROMs, or by any combination of systems, methods, integrated circuits, computer programs, and recording media.

[0012] Effects of the Invention

[0013] According to the cable of one embodiment of the present disclosure, the number of electric wires can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural diagram showing an example of a cable according to the embodiment.

[0015] Figure 2 This is a diagram showing an example of a layer structure of a coaxial line according to an embodiment.

[0016] Figure 3This is a diagram showing an example of a cross-sectional structure of the periphery of the retimer according to the embodiment.

[0017] Figure 4A This is a diagram for explaining power consumption when the coaxial line side is AC coupled.

[0018] Figure 4B This is a diagram for explaining power consumption when the coaxial line side is DC coupled.

[0019] Figure 5 This is a diagram schematically showing the difference between the encoding method on the input side and the encoding method on the output side.

[0020] Figure 6 It is a structural diagram showing another example of the cable according to the embodiment.

[0021] Fig. 7A It is a diagram showing a configuration of an example of a differential single-ended conversion unit according to an embodiment.

[0022] Figure 7B This is a diagram showing a configuration of an example of a single-ended differential conversion unit according to an embodiment.

[0023] Fig. 8A It is a diagram showing the configuration of another example of the differential single-ended conversion unit according to the embodiment.

[0024] Figure 8B It is a diagram showing the configuration of another example of the single-ended differential conversion unit according to the embodiment.

[0025] Fig.9A This is a circuit diagram showing an example of a differential-to-single-ended conversion unit and a single-ended-to-differential conversion unit according to the embodiment.

[0026] Fig. 9B This is a circuit diagram showing the periphery of a single-ended differential converter according to an embodiment. DETAILED DESCRIPTION

[0027] A cable according to one embodiment of the present disclosure comprises a first conversion unit, a second conversion unit and a coaxial line, wherein the first conversion unit and the second conversion unit respectively comprise: a differential single-ended conversion unit which receives a differential signal as input and outputs a single-ended signal; and a single-ended differential conversion unit which receives a single-ended signal as input and outputs a differential signal; the first conversion unit and the second conversion unit are connected via the coaxial line.

[0028] Thus, the differential single-ended conversion unit included in one of the first conversion unit and the second conversion unit converts the differential signal into a single-ended signal and outputs it, and the single-ended differential conversion unit included in the other of the first conversion unit and the second conversion unit converts the input single-ended signal into a differential signal and outputs it. Therefore, it is sufficient to transmit at least the single-ended signal in the coaxial line connecting one differential single-ended conversion unit and one single-ended differential conversion unit, and the wire connecting one differential single-ended conversion unit and one single-ended differential conversion unit can be one, and the number of wires can be reduced.

[0029] For example, the first conversion unit and the second conversion unit may be switchable to use one of the differential-to-single-ended conversion unit and the single-ended-to-differential conversion unit, respectively.

[0030] This makes it possible to support cables in which the direction of signals is unidirectional, such as an HDMI (registered trademark) (High Definition Multimedia Interface) cable and a Display Port cable.

[0031] For example, in each of the first conversion unit and the second conversion unit, the coaxial line side may be DC coupled, and the opposite side of the coaxial line may be AC ​​coupled.

[0032] Thus, the coaxial line side is DC coupled, and thus the current consumption can be made smaller than when the coaxial line side is AC coupled, thereby reducing power consumption.

[0033] For example, the first conversion unit and the second conversion unit may be respectively covered by metal shielding units.

[0034] Thus, EMI (Electro Magnetic Interference) generated from the cable can be suppressed by the metal shield.

[0035] For example, the external shield covering the coaxial line may be connected to the metal shield and a ground portion of a substrate on which the first conversion unit or the second conversion unit is mounted.

[0036] This can further suppress EMI generated from the cable.

[0037] For example, the differential-to-single-ended conversion unit may include two output terminals capable of outputting differential signals, and one of the two output terminals may be connected to a terminal resistor, so that the differential-to-single-ended conversion unit outputs a single-ended signal.

[0038] Thus, by connecting the terminal resistor to one of the two output terminals capable of outputting a differential signal, a differential-to-single-ended converter that outputs a single-ended signal can be realized. For example, a dedicated product for outputting a single-ended signal need not be prepared, and a component that receives a differential signal and outputs a differential signal can be used as a differential-to-single-ended converter.

[0039] For example, the single-ended to differential converter may include two input terminals capable of inputting differential signals, and one of the two input terminals may be connected to a terminal resistor so that a single-ended signal is input to the single-ended to differential converter.

[0040] Thus, by connecting the terminal resistor to one of the two input terminals capable of inputting a differential signal, a single-ended differential conversion unit to which a single-ended signal is input can be realized. For example, it is not necessary to prepare a dedicated product to which a single-ended signal is input, and a component that receives a differential signal and outputs a differential signal can be used as a single-ended differential conversion unit.

[0041] For example, the terminal resistor may be built in the first conversion unit or the second conversion unit.

[0042] Thus, by preliminarily building the terminal resistor into the first conversion unit or the second conversion unit, the number of components can be reduced.

[0043] For example, the differential-to-single-ended conversion unit may include a single-ended output unit that outputs a single-ended signal and a differential output unit that outputs a differential signal, and the single-ended output unit and the differential output unit may be switched to be used.

[0044] Thus, by using the single-ended output part of the single-ended output part and the differential output part, a differential single-ended conversion part that outputs a single-ended signal can be realized. For example, it is not necessary to prepare a dedicated product for outputting a single-ended signal, and a component that can switch to output either a single-ended signal or a differential signal can be used as a differential single-ended conversion part.

[0045] For example, the single-ended to differential converter may include a single-ended input portion to which a single-ended signal is input and a differential input portion to which a differential signal is input, and may be capable of switching between the single-ended input portion and the differential input portion for use.

[0046] Thus, by using the single-ended input part of the single-ended input part and the differential input part, a single-ended differential conversion part to which a single-ended signal is input can be realized. For example, it is not necessary to prepare a dedicated product to which a single-ended signal is input, and a component that can switch to output either a single-ended signal or a differential signal can be used as a single-ended differential conversion part.

[0047] For example, the differential-to-single-ended conversion unit may output a single-ended signal having an amplitude larger than that of an input differential signal.

[0048] Thus, when converting a differential signal into a single-ended signal, the amplitude is increased, thereby ensuring S / N.

[0049] For example, the differential single-ended conversion unit and the single-ended differential conversion unit may respectively include: a differential amplifier, which receives a differential signal as input and outputs a first differential signal; a single-ended differential converter, which receives a signal of one side of the differential signal as input and outputs a second differential signal; and a switch, which receives the first differential signal and the second differential signal as input and switches one side of the first differential signal and the second differential signal for output.

[0050] Thus, the functions of the differential single-ended conversion part and the single-ended differential conversion part can be realized by a differential amplifier, a single-ended differential converter and a switch, and the functions of the differential single-ended conversion part and the single-ended differential conversion part can be switched by switching the signal output by the switch between the first differential signal and the second differential signal.

[0051] For example, the single-ended differential converter may be input with a first input signal, which is one of the differential signals, and a second input signal, and an output terminal of a first output signal corresponding to the first input signal and an input terminal of the second input signal may be coupled via a capacitor.

[0052] Thus, by feeding back the first output signal to the second input signal via the capacitor, it is possible to suppress a decrease in the amplitude of the second input signal, thereby ensuring S / N.

[0053] For example, the second input signal may include a bias signal having an intermediate potential of the differential signal.

[0054] Thus, the first output signal is fed back to the second input signal via the capacitor, which requires bias. Since the second input signal includes a bias signal of an intermediate potential of the differential signal, the bias of the circuit can be ensured.

[0055] For example, a replica circuit identical to the circuit to which the first input signal is input may be connected to an output terminal of a second output signal corresponding to the second input signal.

[0056] This makes it possible to balance the load of the output terminal of the first output signal and the load of the output terminal of the second output signal, thereby improving the waveform of the output signal.

[0057] For example, the single-ended differential conversion unit included in one of the first conversion unit and the second conversion unit may, when an error is detected in the input single-ended signal, notify the differential single-ended conversion unit included in the other of the first conversion unit and the second conversion unit to increase the amplitude of the output single-ended signal.

[0058] Thus, when an error is detected in the input single-ended signal in the single-ended to differential conversion section, the differential to single-ended conversion section can increase the amplitude of the output single-ended signal, thereby improving signal connectivity.

[0059] For example, the encoding method on the input side and the encoding method on the output side of the differential single-ended conversion unit and the single-ended differential conversion unit may be different. Specifically, the encoding method on the input side of the differential single-ended conversion unit may be a binary encoding method, and the encoding method on the output side may be a multi-valued encoding method of three or more, and the encoding method on the input side of the single-ended differential conversion unit may be a multi-valued encoding method of three or more, and the encoding method on the output side may be a binary encoding method.

[0060] This allows multiple values ​​to be expressed in a single-ended signal, and the amount of information in a signal transmitted in one wire increases, so the number of wires can be further reduced accordingly.

[0061] Hereinafter, embodiments will be described in detail with reference to the drawings.

[0062] The numerical values, shapes, materials, components, configuration positions and connection methods of components, steps, and the order of steps shown in the following embodiments are examples and are not intended to limit the present disclosure.

[0063] (Implementation Method)

[0064] Hereinafter, the cable according to the embodiment will be described.

[0065] Figure 1 It is a structural diagram showing an example of the cable 1 according to the embodiment.

[0066] The cable 1 includes a first retimer 10a, a second retimer 10b, and a coaxial line 20. The first retimer 10a is an example of a first conversion unit, and the second retimer 10b is an example of a second conversion unit. When a signal is transmitted at a high speed, the waveform is disturbed due to attenuation of the signal amplitude and the influence of noise, but the jitter is compensated by the first retimer 10a and the second retimer 10b, and the signal can be transmitted at a high speed while maintaining the waveform.

[0067] The first retimer 10a and the second retimer 10b respectively include a differential single-ended conversion section 11 and a single-ended differential conversion section 12. For example, the first retimer 10a includes a plurality of differential single-ended conversion sections 11 and a plurality of single-ended differential conversion sections 12, and the second retimer 10b includes a plurality of differential single-ended conversion sections 11 and a plurality of single-ended differential conversion sections 12. The differential single-ended conversion section 11 receives a differential signal and outputs a single-ended signal. The single-ended differential conversion section 12 receives a single-ended signal and outputs a differential signal.

[0068] The first retimer 10a and the second retimer 10b are connected via a coaxial line 20. In addition, for example, the first retimer 10a and the second retimer 10b are connected to connectors, respectively. The connector is, for example, a USB (Universal Serial Bus) connector. The differential single-ended conversion unit 11 converts a differential signal input from the connector into a single-ended signal and outputs it to the coaxial line 20. The single-ended differential conversion unit 12 converts a single-ended signal input from the coaxial line 20 into a differential signal and outputs it to the connector.

[0069] Thus, the differential single-ended conversion section 11 included in one of the first retimer 10a and the second retimer 10b converts the differential signal into a single-ended signal and outputs it, and the single-ended differential conversion section 12 included in the other of the first retimer 10a and the second retimer 10b converts the input single-ended signal into a differential signal and outputs it. Therefore, the coaxial line 20 connecting one differential single-ended conversion section 11 and one single-ended differential conversion section 12 only needs to transmit the single-ended signal, and the wire connecting one differential single-ended conversion section 11 and one single-ended differential conversion section 12 can be reduced to one wire, and the number of wires can be reduced.

[0070] In addition, in the following, when the first retimer 10a and the second retimer 10b are not distinguished, the first retimer 10a and the second retimer 10b are also described as retimers 10. In addition, the first conversion unit and the second conversion unit are not limited to retimers, and may be redrivers or repeaters. That is, the first retimer 10a and the second retimer 10b may be redrivers or repeaters, respectively.

[0071] Next, use Figure 2 The structure of the coaxial line 20 will be described.

[0072] Figure 2 It is a diagram showing an example of the layer structure of the coaxial line 20 according to the embodiment.

[0073] like Figure 2As shown, the coaxial line 20 is provided with a central conductor at the center, and an insulator, an outer shield, a copper foil, a line identification coating film, and an insulating coating film are provided from the central conductor toward the radial outside. Figure 2 The layer structure shown is an example, and a part of the structure may not be provided, or another structure may be provided.

[0074] Next, use Figure 3 The structure of the periphery of the retimer 10 will be described.

[0075] Figure 3 1 is a diagram showing an example of a cross-sectional structure of the periphery of the retimer 10 according to the embodiment.

[0076] For example, the retimer 10 is mounted on a substrate such as a paddle card. In addition, the substrate is connected to a connector and a coaxial line 20. Thus, the retimer 10 can convert a differential signal input from the connector into a single-ended signal and output it to the coaxial line 20, or can convert a single-ended signal input from the coaxial line 20 into a differential signal and output it to the connector.

[0077] like Figure 3 As shown, for example, the first retimer 10a and the second retimer 10b are respectively covered by a metal shield. The metal shield can suppress EMI generated from the cable 1. In addition, for example, the external shield covering the coaxial line 20 is connected to the metal shield and the grounding portion (for example, a ground pad) of the substrate on which the retimer 10 (the first retimer 10a or the second retimer 10b) is mounted. As a result, EMI generated from the cable 1 can be further suppressed.

[0078] For example, the first retimer 10a and the second retimer 10b may be respectively configured such that the coaxial line 20 side is DC coupled and the opposite side (i.e., the connector side) of the coaxial line 20 is AC coupled. By DC coupling on the coaxial line 20 side, the current consumption can be reduced compared to the case where the coaxial line 20 side is AC coupled, and thus the power consumption can be reduced. Figure 4A and Figure 4B Provide explanation.

[0079] Figure 4A This is a diagram for explaining power consumption when the coaxial line 20 side is AC coupled.

[0080] Figure 4B This is a diagram for explaining power consumption when the coaxial line 20 side is DC coupled.

[0081] like Figure 4AAs shown in FIG. 1 , when the coaxial line 20 side is AC coupled, if a signal with an amplitude of voltage value V is to flow from the current driver to the coaxial line 20, a current of I=2V / R is required. Figure 4B As shown, when the coaxial line 20 side is DC coupled, if a signal with an amplitude of voltage value V is to flow from the voltage driver to the coaxial line 20, a current of I=V / R is required. Therefore, by making the coaxial line 20 side DC coupled, the consumption current can be reduced compared to the case where the coaxial line 20 side is AC coupled, and power consumption can be reduced.

[0082] For example, the differential-to-single-ended converter 11 performs signal processing when converting a differential signal into a single-ended signal. Also, for example, the single-ended-to-differential converter 12 performs signal processing when converting a single-ended signal into a differential signal.

[0083] For example, the differential to single-ended conversion unit 11 may perform signal processing so as to output a single-ended signal having an amplitude greater than that of the differential signal input. By increasing the amplitude when converting the differential signal to the single-ended signal, the S / N ratio can be ensured.

[0084] Furthermore, for example, the differential-to-single-ended conversion unit 11 and the single-ended-to-differential conversion unit 12 may be encoded in such a manner that the encoding method on the input side and the encoding method on the output side of the differential-to-single-ended conversion unit 11 and the single-ended-to-differential conversion unit 12 are different. For example, with respect to the differential-to-single-ended conversion unit 11, the encoding method on the input side (connector side) and the encoding method on the output side (coaxial line 20 side) are different, and with respect to the single-ended-to-differential conversion unit 12, the encoding method on the input side (coaxial line 20 side) and the encoding method on the output side (connector side) are different.

[0085] Figure 5 This is a diagram schematically showing the difference between the encoding method on the input side and the encoding method on the output side. Figure 5 The differential single-ended conversion unit 11 is shown in FIG.

[0086] For example, Figure 5 As shown, the encoding method on the input side (connector side) of the differential single-ended conversion unit 11 is a binary encoding method, and the encoding method on the output side (coaxial line 20 side) is a multi-value encoding method of three or more. In addition, although not shown in the figure, for example, the encoding method on the input side (coaxial line 20 side) of the single-ended differential conversion unit 12 is a multi-value encoding method of three or more, and the encoding method on the output side (connector side) is a binary encoding method. As a result, multiple values ​​can be expressed in a single-ended signal, and the amount of information of the signal transmitted in one wire increases, so the number of wires can be further reduced accordingly.

[0087] In addition, for example, when the single-ended differential conversion unit 12 of one of the first retimer 10a and the second retimer 10b detects an error in the input single-ended signal, it notifies the differential single-ended conversion unit 11 of the other of the first retimer 10a and the second retimer 10b so that the amplitude of the output single-ended signal increases. For example, when the single-ended differential conversion unit 12 of the first retimer 10a detects an error in the input single-ended signal, it notifies the differential single-ended conversion unit 11 of the second retimer 10b so that the amplitude of the output single-ended signal increases. In addition, for example, when the single-ended differential conversion unit 12 of the second retimer 10b detects an error in the input single-ended signal, it notifies the differential single-ended conversion unit 11 of the first retimer 10a so that the amplitude of the output single-ended signal increases.

[0088] For example, the single-ended differential converter 12 stores a pattern such as a PRBS (Pseudo Random Binary Sequence) in advance, and detects an error when a signal having a pattern different from the PRBS is input. In this way, when an error is detected in the input single-ended signal in the single-ended differential converter 12, the differential single-ended converter 11 can increase the amplitude of the output single-ended signal, thereby improving the connectivity of the signal.

[0089] For example, the first retimer 10a and the second retimer 10b may be switched so as to use either the differential single-ended conversion section 11 or the single-ended differential conversion section 12. Figure 6 Provide explanation.

[0090] Figure 6 It is a structural diagram showing another example of the cable 1 according to the embodiment.

[0091] like Figure 6 As shown, the differential single-ended conversion section 11 and the single-ended differential conversion section 12 are connected in parallel in one route, and it is possible to switch to use one of the differential single-ended conversion section 11 and the single-ended differential conversion section 12. For example, the first retimer 10a has a plurality of combinations of the differential single-ended conversion section 11 and the single-ended differential conversion section 12 connected in parallel, and the second retimer 10b has a plurality of combinations of the differential single-ended conversion section 11 and the single-ended differential conversion section 12 connected in parallel. For example, by rewriting the register using a switching signal, switching is performed to use one of the differential single-ended conversion section 11 and the single-ended differential conversion section 12. In addition, the above switching can also be performed by an external pin or the like.

[0092] For example, in the first retimer 10a, when all the combinations of the differential single-ended conversion sections 11 and the single-ended differential conversion sections 12 are switched to use only the differential single-ended conversion section 11 among the differential single-ended conversion sections 11 and the single-ended differential conversion sections 12, in the second retimer 10b, all the combinations of the differential single-ended conversion sections 11 and the single-ended differential conversion sections 12 are switched to use only the single-ended differential conversion section 12 among the differential single-ended conversion sections 11 and the single-ended differential conversion sections 12. In this case, a signal is input to the first retimer 10a, and a signal is output from the second retimer 10b.

[0093] For example, in the first retimer 10a, when all the combinations of the differential single-ended conversion sections 11 and the single-ended differential conversion sections 12 are switched to use only the single-ended differential conversion sections 12 among the differential single-ended conversion sections 11 and the single-ended differential conversion sections 12, in the second retimer 10b, all the combinations of the differential single-ended conversion sections 11 and the single-ended differential conversion sections 12 are switched to use only the differential single-ended conversion sections 11 and the single-ended differential conversion sections 12. In this case, the signal is input to the second retimer 10b, and the signal is output from the first retimer 10a.

[0094] This makes it possible to support cables such as HDMI cables and DisplayPort cables whose signal direction is unidirectional.

[0095] Next, use Figures 7A to 9B The implementation method of the differential single-ended conversion unit 11 and the single-ended differential conversion unit 12 is described. For example, the differential single-ended conversion unit 11 has Fig. 7A , Fig. 8A or Fig.9A The implementation method described, the single-ended differential conversion unit 12 has Figure 7B , Figure 8B or Fig.9A The implementation method of the description.

[0096] Fig. 7A It is a diagram showing a configuration of an example of the differential to single-ended conversion unit 11 according to the embodiment.

[0097] like Fig. 7A As shown, the differential single-ended conversion unit 11 may have two output terminals t1 and t2 capable of outputting differential signals, and one of the two output terminals t1 and t2 is connected to a terminal resistor, thereby outputting a single-ended signal. In this way, by connecting the terminal resistor to one of the two output terminals t1 and t2 capable of outputting differential signals, a differential single-ended conversion unit 11 capable of outputting a single-ended signal can be realized. For example, a dedicated product for outputting a single-ended signal may not be prepared, and a component that receives a differential signal and outputs a differential signal may be used as the differential single-ended conversion unit 11.

[0098] Figure 7B It is a diagram showing a configuration of an example of the single-ended to differential conversion unit 12 according to the embodiment.

[0099] like Figure 7B As shown, the single-ended differential conversion unit 12 may have two input terminals t11 and t12 that can input differential signals, and one of the two input terminals t11 and t12 is connected to a terminal resistor, so that a single-ended signal is input. In this way, by connecting the terminal resistor to one of the two input terminals t11 and t12 that can input differential signals, a single-ended differential conversion unit 12 that can input a single-ended signal can be realized. For example, a dedicated product that can input a single-ended signal can be used as a single-ended differential conversion unit 12 without preparing a dedicated product that can input a differential signal.

[0100] For example, Fig. 7A The differential single-ended conversion unit 11 and Figure 7B The single-ended to differential conversion section 12 shown is the same component, and can be used as either the differential single-ended conversion section 11 or the single-ended to differential conversion section 12 depending on the connection method of the terminal resistor.

[0101] In addition, the terminal resistor may be built into the first retimer 10a or the second retimer 10b. For example, the terminal resistor connected to the differential single-ended conversion section 11 or the single-ended differential conversion section 12 of the first retimer 10a may be built into the first retimer 10a, and the terminal resistor connected to the differential single-ended conversion section 11 or the single-ended differential conversion section 12 of the second retimer 10b may be built into the second retimer 10b. By building the terminal resistor into the first retimer 10a or the second retimer 10b in advance, the number of components can be reduced.

[0102] Fig. 8A It is a diagram showing the configuration of another example of the differential to single-ended conversion unit 11 according to the embodiment.

[0103] like Fig. 8A As shown, the differential-to-single-ended conversion unit 11 may include a single-ended output unit 11a that outputs a single-ended signal and a differential output unit 11b that outputs a differential signal, and may be switched to use one of the single-ended output unit 11a and the differential output unit 11b. For example, by rewriting a register using a switching signal, it is possible to switch to use one of the single-ended output unit 11a and the differential output unit 11b. Alternatively, the switching may be performed by an external pin or the like.

[0104] By using the single-ended output unit 11a of the single-ended output unit 11a and the differential output unit 11b, a differential single-ended conversion unit 11 that outputs a single-ended signal can be realized. For example, a dedicated product that outputs a single-ended signal may not be prepared, and a component that can switch to output either a single-ended signal or a differential signal may be used as the differential single-ended conversion unit 11.

[0105] Figure 8B It is a diagram showing the configuration of another example of the single-ended differential conversion unit 12 according to the embodiment.

[0106] like Figure 8B As shown, the single-ended to differential conversion unit 12 may include a single-ended input unit 12a to which a single-ended signal is input and a differential input unit 12b to which a differential signal is input, and may be switched to use one of the single-ended input unit 12a and the differential input unit 12b. For example, by rewriting a register according to a switching signal, the single-ended input unit 12a and the differential input unit 12b may be switched to use one of the single-ended input unit 12a and the differential input unit 12b. Alternatively, the switching may be performed by an external pin or the like.

[0107] By using the single-ended input section 12a of the single-ended input section 12a and the differential input section 12b, a single-ended to differential conversion section 12 to which a single-ended signal is input can be realized. For example, a dedicated product to which a single-ended signal is input may not be prepared, and a component that can switch to output either a single-ended signal or a differential signal may be used as the differential conversion section 12.

[0108] For example, the differential single-ended conversion unit 11 and the single-ended differential conversion unit 12 can be realized by a component having a single-ended output unit 11a and a differential output unit 11b, and a single-ended input unit 12a and a differential input unit 12b. For example, the component can be used as the differential single-ended conversion unit 11 by switching to use the single-ended output unit 11a and the differential input unit 12b. In addition, for example, the component can be used as the single-ended differential conversion unit 12 by switching to use the differential output unit 11b and the single-ended input unit 12a.

[0109] Fig.9A 1 is a circuit diagram showing an example of the differential-to-single-ended conversion unit 11 and the single-ended-to-differential conversion unit 12 according to the embodiment.

[0110] The differential single-ended conversion unit 11 and the single-ended differential conversion unit 12 respectively include a differential amplifier 31, a single-ended differential converter 32, and a switch 33. The differential amplifier 31 receives a differential signal and outputs a first differential signal. The single-ended differential converter 32 receives a signal of one side of the differential signal and outputs a second differential signal. Specifically, the single-ended differential converter 32 receives a signal of one side of the differential signal, i.e., a first input signal, and a second input signal. The switch 33 receives a first differential signal and a second differential signal and switches and outputs one of the first differential signal and the second differential signal.

[0111] Thus, both the function of the differential single-ended conversion unit 11 and the function of the single-ended differential conversion unit 12 can be realized through the differential amplifier 31, the single-ended differential converter 32 and the switch 33. By switching the signal output by the switch 33 between the first differential signal and the second differential signal, the function of the differential single-ended conversion unit 11 and the function of the single-ended differential conversion unit 12 can be switched.

[0112] For example, the differential-to-single-ended conversion unit 11 can be realized by switching the signal outputted from the switch 33 to the first differential signal. In this case, one of the first differential signals outputted from the switch 33 is used as a single-ended signal.

[0113] For example, by switching the signal output by the switch 33 to the second differential signal, the single-ended differential conversion unit 12 can be implemented.

[0114] Here, use Fig. 9B The peripheral circuits of the single-ended differential converter 32 will be described.

[0115] Fig. 9B is a circuit diagram of the periphery of the single-ended differential converter 32 according to the embodiment. Fig.9A The dotted line encloses the portion of the circuit diagram.

[0116] like Fig. 9B As shown, the single-ended differential converter 32 is composed of transistors Tr1 and Tr2. A first input signal is input to the gate of transistor Tr1, and a first output signal corresponding to the first input signal is output from an output terminal (output terminal t22 described later) connected to the drain of transistor Tr1. A second input signal is input to the gate of transistor Tr2, and a second output signal corresponding to the second input signal is output from an output terminal (output terminal t23 described later) connected to the drain of transistor Tr2.

[0117] The output terminal of the first output signal and the input terminal of the second input signal are coupled via capacitor C1. Fig.9AAs shown in FIG. 1 , the output terminal t22 of the single-ended differential converter 32 is connected to the drain of the transistor Tr1 in the single-ended differential converter 32. In addition, the input terminal of the second input signal is as shown in FIG. Fig.9A As shown, it is the input terminal t21 of the single-ended differential converter 32, and is connected to the gate of the transistor Tr2 in the single-ended differential converter 32.

[0118] In this way, the first output signal is fed back to the second input signal via the capacitor C1, and the inverted signal is input as the second input signal, thereby ensuring the S / N.

[0119] For example, the second input signal includes a bias signal of an intermediate potential of the differential signal. The bias signal is generated by the bias circuit 41. Since the first output signal is fed back to the second input signal via the capacitor C1, bias is required. Since the second input signal includes a bias signal of an intermediate potential of the differential signal, the bias of the circuit can be ensured.

[0120] For example, a replica circuit 42 which is the same as the circuit to which the first input signal is input is connected to the output terminal of the second output signal. Fig.9A As shown in FIG. 1 , it is an output terminal t23 of the single-ended differential converter 32, and is connected to the drain of the transistor Tr2 in the single-ended differential converter 32. The replica circuit 42 has a transistor Tr3, a resistor R2, and a current source A2, similarly to the circuit (transistor Tr1, resistor R1, and current source A1) to which the first input signal is input. In addition, the replica circuit 42 has a capacitor C2 connected between the drain of the transistor Tr2 and the gate of the transistor Tr3.

[0121] Thus, the output terminal of the first output signal is connected to the resistor R2, transistor Tr3, and current source A2 of the replica circuit 42 via the capacitor C1, and the output terminal of the second output signal is connected to the resistor R2, transistor Tr3, and current source A2 of the replica circuit 42 via the capacitor C2. That is, the load of the output terminal of the first output signal and the load of the output terminal of the second output signal can be balanced. Therefore, the waveform of the output signal can be improved.

[0122] As described above, in the cable 1, the differential single-ended conversion section 11 included in one of the first retimer 10a and the second retimer 10b converts a differential signal into a single-ended signal and outputs it, and the single-ended differential conversion section 12 included in the other of the first retimer 10a and the second retimer 10b converts an input single-ended signal into a differential signal and outputs it. Therefore, it is sufficient to transmit at least a single-ended signal in the coaxial line 20 connecting one differential single-ended conversion section 11 and one single-ended differential conversion section 12, and the wire connecting one differential single-ended conversion section 11 and one single-ended differential conversion section 12 can be one, and the number of wires can be reduced.

[0123] (Other embodiments)

[0124] The cable 1 of one or more technical solutions of the present disclosure is described above based on the implementation, but the present disclosure is not limited to these implementations. As long as it does not deviate from the main purpose of the present disclosure, solutions obtained by applying various deformations that a person skilled in the art can think of to the implementation, and solutions constructed by combining constituent elements in different implementations can also be included in the scope of one or more technical solutions of the present disclosure.

[0125] For example, in the above-described embodiment, an example is described in which the first retimer 10 a and the second retimer 10 b are each covered by a metal shield, but they may not be covered by a metal shield.

[0126] For example, in the above embodiment, the external shield covering the coaxial line 20 is connected to the metal shield and the ground of the substrate on which the first and second retimers 10a and 10b are mounted, but it does not need to be connected to them.

[0127] For example, in the above-described embodiment, an example is described in which the differential-to-single-ended conversion unit 11 performs signal processing when converting a differential signal into a single-ended signal. However, the signal processing may not be performed.

[0128] For example, in the above-described embodiment, an example is described in which the single-ended to differential converter 12 performs signal processing when converting a single-ended signal into a differential signal, but signal processing may not be performed.

[0129] For example, in the above-mentioned embodiment, an example is described in which the single-ended differential conversion unit 12 of one of the first retimer 10a and the second retimer 10b notifies the differential single-ended conversion unit 11 of the other of the first retimer 10a and the second retimer 10b to increase the amplitude of the output single-ended signal when an error is detected with respect to the input single-ended signal, but this notification may not be performed.

[0130] Industrial Applicability

[0131] The present disclosure can be applied to a cable including a retimer and the like.

[0132] Description of Reference Numerals

[0133] 1 Cable

[0134] 10 Retimer

[0135] 10a First retimer

[0136] 10b Second retimer

[0137] 11 Differential to single-ended conversion unit

[0138] 11a Single-ended output section

[0139] 11b Differential output section

[0140] 12 Single-ended differential conversion unit

[0141] 12a Single-ended input section

[0142] 12b Differential input section

[0143] 20 Coaxial line

[0144] 31 Differential Amplifier

[0145] 32 Single-ended differential converter

[0146] 33 Switcher

[0147] 41 Bias Circuit

[0148] 42 Copy Circuit

[0149] A1, A2 current source

[0150] C1, C2 capacitors

[0151] R1, R2 resistors

[0152] t1, t2, t22, t23 output terminals

[0153] t11, t12, t21 input terminals

[0154] Tr1, Tr2, Tr3 transistors

Claims

1. A cable, characterized in that: have: a first transformation unit; a second conversion unit; and Coaxial line, The first conversion unit and the second conversion unit respectively include: a differential-to-single-ended conversion unit that receives a differential signal and outputs a single-ended signal; and The single-ended to differential conversion unit receives a single-ended signal and outputs a differential signal. The first conversion unit and the second conversion unit are connected via the coaxial line.

2. The cable according to claim 1, characterized in that The first conversion unit and the second conversion unit can each be switched to use one of the differential-to-single-ended conversion unit and the single-ended-to-differential conversion unit.

3. The cable according to claim 1 or 2, characterized in that: In each of the first conversion unit and the second conversion unit, the coaxial line side is DC coupled, and the opposite side of the coaxial line is AC coupled.

4. The cable according to any one of claims 1 to 3, characterized in that: The first conversion part and the second conversion part are respectively covered by metal shielding parts.

5. The cable according to claim 4, characterized in that The external shield covering the coaxial line is connected to the metal shield and a ground portion of a substrate on which the first conversion unit or the second conversion unit is mounted.

6. The cable according to any one of claims 1 to 5, characterized in that: The differential-to-single-ended conversion unit has two output terminals capable of outputting differential signals, and one of the two output terminals is connected to a terminal resistor, so that the differential-to-single-ended conversion unit outputs a single-ended signal.

7. The cable according to any one of claims 1 to 6, characterized in that: The single-ended differential conversion unit has two input terminals to which differential signals can be input, and one of the two input terminals is connected to a terminal resistor so that a single-ended signal is input to the single-ended differential conversion unit.

8. The cable according to claim 6 or 7, characterized in that: The terminal resistor is built in the first conversion unit or the second conversion unit.

9. The cable according to any one of claims 1 to 8, characterized in that: The differential-to-single-ended conversion section includes a single-ended output section that outputs a single-ended signal and a differential output section that outputs a differential signal, and can switch between the single-ended output section and the differential output section for use.

10. The cable according to any one of claims 1 to 9, characterized in that: The single-ended to differential conversion section includes a single-ended input section to which a single-ended signal is input and a differential input section to which a differential signal is input, and can switch between the single-ended input section and the differential input section for use.

11. The cable according to any one of claims 1 to 10, characterized in that: The differential-to-single-ended conversion unit outputs a single-ended signal having an amplitude greater than that of the input differential signal.

12. The cable according to any one of claims 1 to 11, characterized in that: The above-mentioned differential single-ended conversion part and the above-mentioned single-ended differential conversion part respectively have: A differential amplifier is input with a differential signal and outputs a first differential signal; a single-ended differential converter which receives one of the differential signals as input and outputs a second differential signal; as well as The switch receives the first differential signal and the second differential signal, switches one of the first differential signal and the second differential signal, and outputs the signal.

13. The cable according to claim 12, characterized in that The single-ended differential converter receives a first input signal, which is one of the differential signals, and a second input signal, and an output terminal of a first output signal corresponding to the first input signal and an input terminal of the second input signal are coupled via a capacitor.

14. The cable according to claim 13, characterized in that The second input signal includes a bias signal having an intermediate potential of the differential signal.

15. The cable according to claim 13 or 14, characterized in that: The same replica circuit as the circuit to which the first input signal is input is connected to an output terminal of a second output signal corresponding to the second input signal.

16. The cable according to any one of claims 1 to 15, characterized in that: The single-ended differential conversion unit included in one of the first conversion unit and the second conversion unit, when an error is detected in the input single-ended signal, notifies the differential single-ended conversion unit included in the other of the first conversion unit and the second conversion unit so as to increase the amplitude of the output single-ended signal.

17. The cable according to any one of claims 1 to 16, characterized in that: The differential-to-single-ended conversion unit and the single-ended-to-differential conversion unit each have different encoding methods on the input side and different encoding methods on the output side.

18. The cable according to claim 17, characterized in that The encoding method on the input side of the differential single-ended conversion unit is a binary encoding method, and the encoding method on the output side is a multi-value encoding method of three or more values. The encoding method on the input side of the single-ended differential conversion unit is a multi-value encoding method of three or more values, and the encoding method on the output side is a binary encoding method.

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