TWI771132B - A source node architecture for an optical communication channel - Google Patents

Abstract

A source node architecture for an optical communication channel comprises: a source device and a transmitting device, wherein the transmitting device is coupled to a power source from the source device, for generating a first current to the source device so as to output a first electrical signal from the source device and a second current to the transmitting device comprising a first optical device so as to generate a first optical signal to a fiber wire.

Description

A Source Node Architecture for Optical Communication Channels

The present invention relates to an optical communication circuit, particularly a current supply circuit to excite optical signals to an optical fiber line.

FIG. 1 shows a conventional connection structure for transmitting TMDS signals using copper wires, wherein the TMDS signals are transmitted from a source node to a sink node, and a DC current is supplied from the sink node to the source node to transmit the TMDS signal. However, using copper wires to transmit video data has limited bandwidth and is susceptible to noise or interference.

Therefore, the present invention proposes a solution to overcome the above-mentioned problems.

An object of the present invention is to provide a circuit for supplying current to a source device and a sending device for converting electrical signals into optical signals for transmission to optical fiber lines.

The present invention discloses a source node architecture for an optical communication channel. The source node architecture includes: a source device; and a sending device including a first optical diode, wherein the sending device is coupled to a source from the a power supply of the source device to generate a first current and a second current, wherein the first current is input to the source device to output a first electrical signal, and the second current is input to the source device The transmitting device enables the first photodiode to generate a first optical signal to an optical fiber.

In one embodiment, the first current flows along a current path from the drain to the source of a field effect transistor inside the source device.

In one embodiment, the total current of the first current and the second current is controlled within a predetermined range.

In one embodiment, the first photodiode is a laser photodiode.

In one embodiment, the first electrical signal is a single-ended signal.

In one embodiment, the first electrical signal is a pair of differential signals.

In one embodiment, the source node architecture includes a DC-to-DC converter for converting a first voltage of the power supply to a second voltage and a sub-circuit in series with the DC-to-DC converter , wherein the sub-circuit receives the second voltage to generate the first current to the source device to output the first electrical signal and generates the second current to the transmitter, so that the The first photodiode generates a first optical signal to an optical fiber line.

In one embodiment, the subcircuit includes a resistor and a Zener diode in parallel with the resistor to control the voltage drop across the resistor, wherein the first terminal of the resistor and the first terminal of the Zener diode is electrically connected to a first node, and the second terminal of the resistor and the second terminal of the Zener diode are electrically connected to a second node , wherein the first current supplied to the source device and the second current supplied to the transmitting device both pass through the second node.

In one embodiment, the first current is generated by the transmitting device, wherein the first current flows along a current path from the drain to the source of a field effect transistor inside the source device.

In one embodiment, the sub-circuit includes a resistor and a zener diode connected in parallel with the resistor, wherein a first end of the resistor is electrically connected to a first end of the zener diode At the first node, the second terminal of the resistor and the second terminal of the Zener diode are electrically connected to the second node, wherein the first current is supplied to the source terminal through the second node device, the second current is provided to the transmitting device through the first node.

In one embodiment, the pair of differential signals are time-minimized differential signals (TMDS).

In one embodiment, the first current is generated by the sub-circuit, wherein the first current flows along a current path from drain to source of a field effect transistor inside the source device .

In one embodiment, the first electrical signal is capacitively coupled to the transmitting device.

In one embodiment, the first photodiode is a laser diode for generating the first optical signal.

In one embodiment, the transmitting device and the subcircuit are integrated in a single wafer.

In one embodiment, the optical communication channel is used to transmit a high-definition multimedia interface (HDMI) video data signal.

In one embodiment, the optical communication channel is used to transmit the video data signal of the Display Port.

In one embodiment, the single wafer is based on CMOS technology.

The present invention discloses a source node architecture for an optical communication channel. The source node architecture includes: a source device; a sending device including a first photodiode; and a first sub-circuit, wherein the The first sub-circuit is coupled to the transmitting device and a power supply from the source device, wherein the first sub-circuit generates a first current to the source device to output a first power from the source device A signal is sent to the sending device, and the first sub-circuit generates a second current to the sending device so that the first photodiode generates a first optical signal to an optical fiber.

In one embodiment, the first current flows along a current path from the drain to the source of a field effect transistor inside the source device.

In one embodiment, the total current of the first current and the second current is controlled within a predetermined range.

In one embodiment, the first current is controlled within a first predetermined range, and the second current is controlled within a second predetermined range.

In one embodiment, the first sub-circuit includes a DC-to-DC converter for converting a first voltage of the power supply to a second voltage and a first DC-to-DC converter in series with the DC-DC converter Two sub-circuits, wherein the second sub-circuit receives the second voltage to generate the first current to the source device to output the first electrical signal and generates the second current to the transmitter The device enables the first photodiode to generate a first optical signal to an optical fiber.

In one embodiment, the second subcircuit includes a resistor and a Zener diode in parallel with the resistor, wherein a first terminal of the resistor and a first terminal of the Zener diode are electrically connected to each other. is electrically connected to the first node, and the second end of the resistor and the second end of the Zener diode are electrically connected to the second node, wherein the first current and the second current pass through the The second node is provided to the source device and the sending device.

In one embodiment, the second subcircuit includes a resistor and a zener diode in parallel with the resistor, wherein a first end of the resistor and a first end of the zener diode is electrically connected to the first node, the second end of the resistor and the second end of the Zener diode are electrically connected to the second node, wherein the first current is supplied to the second node through the second node In the source device, the second current is provided to the sending device through the first node.

In one embodiment, the first electrical signal is coupled to the transmitting device via a capacitor.

After referring to the embodiments and detailed techniques of the present invention described in the following paragraphs and the accompanying drawings, those skilled in the art can understand the technical features and implementation aspects of the present invention.

A detailed description of the present invention is described later, and the preferred embodiments described herein are for the purpose of illustration and description, and are not intended to limit the scope of the present invention.

HDMI and DP interfaces grew along with USB 3.1/3.2. If the distance is more than 5 meters, HDMI 2.1 Active Optical Cable (AOC) is required for 4K display. 8K displays require HDMI 2.1 AOC if the distance is more than 1 meter. Active Optical Cable (AOC) can overcome the needs of long-distance video display applications. The combination of HDMI/DP and USB optical cable is suitable for applications such as VR headset or NB extension.

HDMI Active Optical Cables provide fast and high quality video for various applications such as indoor/outdoor digital signage, 4K/8K TVs, medical image displays or game consoles.

The present invention discloses a source node architecture for an optical communication channel. The source node architecture includes: a source device; and a sending device, which includes a first optical diode, wherein the sending device is coupled to a source from A power supply of the source device to generate a first current to the source device to output a first electrical signal from the source device to the sending device and a second current to the sending device to enable the first electrical signal An optical diode generates a first optical signal to an optical fiber line, wherein the source node architecture can be implemented in various ways, which will be described below.

FIG. 2 shows a circuit for supplying current to the source device 201 and the transmitting device (TX) 202 to generate the first electrical signal 201a and the first optical signal 202a, wherein the circuit generates the first current I(1) to The source device 201 outputs the first electrical signal 201a and the second current I(2) to the transmitting device (TX) 202 to generate the first optical signal 202a, wherein the first current I(1) and the second current I(2) The total current is controlled within a preset range.

In one embodiment, as shown in FIG. 2 , the sending device 202 is connected to a power source 300 such as +5v, wherein the power source 300 such as +5v can be used by the sending device 202 to determine whether the source device 201 is active. The transmitting device 202 will provide a first current I(1) to the source device 201 and a second current I(2) to the transmitting device (TX) 202 comprising an optical diode for generating the first optical signal 202a.

In one embodiment, the first electrical signal 201a is a single-ended signal.

In one embodiment, the first electrical signal 201a is a differential pair of signals.

In one embodiment, as shown in FIG. 2 , the first current I( 1 ) flow path includes from the drain to the source of the field effect transistor (Field Effect Transistor) inside the source device 201 . a current path 201b.

In one embodiment, as shown in FIG. 3A, the circuit includes a sub-circuit 203, which may be called Transmit DC feedback, wherein the sub-circuit 203 is connected to a power source 300, such as +5v , to generate the first current I(1) and output it to the source device 201 via the transmitting device (TX Device) 202 to output the first electrical signal 201a, and to generate the second current I(2) to provide to the transmitting device (TX) 202 , the transmitting device (TX) 202 includes an optical diode for generating the first optical signal 202a.

In one embodiment, as shown in FIG. 3B , the sub-circuit 203 includes a direct current (DC-DC) converter 203 a and a sub-circuit 203 p, wherein the DC-DC converter 203 a is used to convert the first voltage 300 Converted to the second voltage V(a), wherein the sub-circuit 203p receives the second voltage V(a) and generates the first current I(1) to the source device 201 to output the first electrical signal 201a and the second current I(2 ) to a photodiode, such as a photodiode LD, to generate the first optical signal 202a.

In one embodiment, as shown in FIG. 3B , the sub-circuit 203p includes a resistor R1 and a Zener Diode Z1 connected in parallel with the resistor R1 for controlling the voltage drop across the resistor R1, wherein, The first end of the resistor R1 and the first end of the Zener diode Z1 are electrically connected to the first node 201N1, and the second end of the resistor R1 and the second end of the Zener diode Z1 are electrically connected to the second node 201N2, wherein the total current I(1)+I(2) flows from the first node 201N1 to the second node 201N2, wherein the first current I(1) is provided through the second node 201N2 to flow to the source device 201 to generate the first current The signal 201a and the second current I(2) flow to the transmitting device 202 for the photodiode LD to generate the first optical signal 202a.

In Figure 3B, the following voltage requirements are met: (1) V(b) > transmit (TX) voltage requirements to drive photodiodes such as laser diodes to maintain eye quality; (2) V(b) = source (3) V(z) = V(a)–V(b) = [I(1) + I(2) ] * R1; (4) V(a) is chosen to support V (b) to meet the above requirements.

In Figure 3B, the following current requirements are satisfied: (1) I(1) + I(2) < maximum power consumption; (2) I(1) > drain current requirement of the source device; (3) I(2 ) > the current requirement of the transmitting device 202 to drive the photodiode such as the laser diode to maintain the eye diagram quality.

In one embodiment, the transmitting device 202 and the subcircuit 203 are integrated in a single die.

In one embodiment, the transmitting device 202 and the subcircuit 203p are integrated in a single die.

In one embodiment, the transmitting device 202 and the subcircuit 203 are separate devices.

In one embodiment, the circuit is used to provide current to four source devices and four photodiodes to four optical signals to four fiber optic lines.

In one embodiment, the circuit is based on CMOS technology.

In one embodiment, the circuit is used to transmit DP video data.

In one embodiment, the circuit is used to transmit HDMI video data.

Fig. 3C shows a flow chart of calibrating voltage and current requirements, please refer to Fig. 3B at the same time, wherein in step S301: start the calibration process; step S302: select the voltage V(a) in Fig. 3B; step S303: adjust R1 and V(z) meets the voltage requirement (1); In step S304: check the eye diagram of the signal, if the eye diagram meets the requirement, go to the next step 305, otherwise go to step 302, and reselect the voltage V(a) in FIG. 3B ; Step S304: Check the eye diagram of the signal; Step S305: Adjust R1 and V(z) to meet the voltage requirement (1); Check whether V(b) satisfies: 3.125V < V(b) < 3.475V, if not , go to step S306: adjust R1 to meet the voltage requirement (4), otherwise go to step S307: apply source-to-drain TMDS current; step S308: check the eye diagram of the signal; in step S309, end the calibration process.

In one embodiment, as shown in FIG. 4A , the circuit includes a sub-circuit 203, which can be referred to as Transmit DC feedback, wherein the sub-circuit 203 is connected to a power source 300 such as +5v to generate a first current I(1) to the source device 201 to generate a first electrical signal 201a and a second current I(2) to output to a transmitting device (TX) 202 including an optical diode for generating the first optical signal 202a, wherein The first electrical signal 201a is AC coupled to the transmitting device (TX) 202 through the capacitor C1.

In one embodiment, as shown in FIG. 4B, the sub-circuit 203 includes a DC-DC converter 203a and a sub-circuit 203p, wherein the DC-DC converter 203a is used to convert the first voltage 300 into the second voltage V(a ), wherein the sub-circuit 203p receives the second voltage V(a) and generates the first current I(1) to the source device 201 to output the first electrical signal 201a and the second current I(2) to the photodiode LD to A first optical signal 202a is generated.

In one embodiment, as shown in FIG. 4B, the sub-circuit 203p includes a resistor R1 and a zener diode Z1 in parallel with the resistor R1, the zener diode Z1 is used to control the voltage drop across the resistor R1, wherein the resistor R1 The first end of Z1 and the first end of the Zener diode Z1 are electrically connected to the first node 201N1, and the second end of the resistor and the second end of the Zener diode are electrically connected to the second node 201N2. The first current I(1) of the source device 201 is provided through the second node 201N2, and the second current I(2) flowing to the transmitting device 202 is provided through the first node 201N1.

In one embodiment, as shown in FIG. 4B, the first current I(1) flowing to the source device 201 is provided through the first node 201N1 and an inductor L1.

In one embodiment, as shown in FIG. 4B , the second current I(2) flowing to the transmitting device (TX) 202 is provided through the first node 201N1 and the resistor R2 for enabling the photodiode LD to generate the first optical signal 202a.

In Figure 4B, the following voltage requirements should be met: (1) V(c) > TX voltage requirements (to drive the laser diode to maintain eye quality); (2) V(b) = voltage consumption of the source device ; (3) V(z) = V(a)-V(b) = [I(1) + I(2) ] * R1; (4) V(a) is chosen to support V(b) and V( c) meet all requirements.

In FIG. 4B, the following current requirements should be satisfied: (1) I(1)+I(2) < maximum current requirement; (2) I(1) > drain current requirement of the source device; (3) I( 2) > TX current requirement (to drive the laser diode to maintain eye quality).

Fig. 4C shows a flow chart of calibrating voltage and current requirements, please refer to Fig. 4B at the same time, wherein in step S401: start the calibration process; step S402: select the voltage V(a) in Fig. 4B; step S403: adjust R2 and V(z) meets the voltage requirement (1); Step S404: Check the eye diagram of the signal, if the eye diagram meets the requirement, go to next step 405, otherwise go to step 402, and reselect the voltage V(a) in FIG. 4B; Step S405: Adjust R1 and V(z) to meet the voltage requirement (1); Check whether V(b) satisfies: 3.125V<V(b)<3.475V, if not, proceed to Step 406: Adjust R1 to meet the voltage requirement (4), otherwise, go to step 407: apply the source-to-drain TMDS current; step S408: check the eye diagram of the signal; in step S409, end the calibration process.

In one embodiment, the transmitting device 202 and the subcircuit 203 are integrated in a single die.

In one embodiment, the transmitting device 202 and the subcircuit 203p are integrated in a single die.

In one embodiment, the transmitting device 202 and the subcircuit 203 are separate devices.

In one embodiment, the optical diode LD is a vertical cavity surface emitting laser (VCSEL) diode.

Although the present invention is disclosed by the above-mentioned preferred embodiments, it is not intended to limit the present invention, and any person who is familiar with the similar arts can make some changes and modifications without departing from the spirit and scope of the present invention. Although these possible modifications and substitutions have not been fully disclosed in the above description, the protection scope of the patent appended to this specification has substantially covered all of these aspects.

201: Source device 202: Sending device I(1): first current I(2): second current 201a: First electrical signal 202a: first optical signal 201b: Current Path 300: Power V(a): second voltage 203p: Subcircuits LD: Photodiode R1: Resistor Z1: Ziner diode 201N1: First Node 201N2: Second Node

The foregoing aspects of the present invention and the attendant advantages will be more fully understood by reference to the following detailed description and accompanying drawings, wherein: Figure 1 shows a connection structure diagram of a traditional copper wire for transmitting TMDS signals. FIG. 2 shows a circuit for providing current to the source device and the transmitter device according to an embodiment of the present invention. FIG. 3A shows a circuit for providing current to the source device and the transmitter device according to an embodiment of the present invention. FIG. 3B shows a circuit of the Transmit DC feedback of FIG. 3A . Figure 3C shows a flow chart for calibration of voltage and current in Transmit DC feedback. FIG. 4A shows a circuit for supplying current to a source device and a transmitter device according to an embodiment of the present invention. FIG. 4B shows a circuit of the Transmit DC feedback of FIG. 4A . Figure 4C shows a flow chart for calibration of voltage and current in Transmit DC feedback.

201: Source device

202: Sending device

300: Power

I(1): first current

I(2): second current

201a: First electrical signal

202a: first optical signal

201b: Current Path

Claims (20)

A source node architecture for an optical communication channel, the source node architecture comprising: a source device; and a sending device, wherein the sending device is coupled to a power source from the source device to generate a first current and a second current, wherein the first current is input to the source device to The source device outputs a first electrical signal, and the second current is input to the sending device so that a first photodiode generates a first optical signal. The source node architecture of claim 1, wherein the first current flows along a current path from a drain to a source of a field effect transistor inside the source device. The source node architecture of claim 1, wherein a total current of the first current and the second current is controlled within a predetermined range. The source node architecture of claim 1, wherein the first current is controlled within a first predetermined range and the second current is controlled within a second predetermined range. The source node architecture of claim 1, wherein the source node architecture includes a DC-to-DC converter that converts a first voltage of the power supply to a second voltage and is connected in series with the DC-to-DC converter a sub-circuit of the , wherein the sub-circuit receives the second voltage to generate the first current and the second current. The source node architecture of claim 5, wherein the subcircuit includes a resistor and a Zener diode in parallel with the resistor to control the voltage drop across the resistor, wherein the first terminal of the resistor and the first terminal of the Zener diode is electrically connected to a first node, the second terminal of the resistor and the second terminal of the Zener diode are electrically connected to a second node, wherein Both the first current and the second current pass through the second node. The source node architecture of claim 6, wherein the first current is generated by the transmitting device, wherein the first current is along a path from a drain to a source of a field effect transistor inside the source device a current path to flow. The source node architecture of claim 5, wherein the subcircuit includes a resistor and a zener diode in parallel with the resistor, wherein a first end of the resistor and a terminal of the zener diode The first terminal is electrically connected to a first node, the second terminal of the resistor and the second terminal of the Zener diode are electrically connected to a second node, wherein the first current passes through the The second node is provided to the source device, and the second current is provided to the transmission device through the first node. The source node architecture of claim 8, wherein the first current is generated by the subcircuit, wherein the first current flows along from the drain of a field effect transistor inside the source device to the source A current path of the pole flows. The source node architecture of claim 9, wherein the first electrical signal is coupled to the transmitting device via a capacitor. The source node architecture of claim 1, wherein the first photodiode is a laser diode. The source node architecture of claim 5, wherein the transmitting device and the subcircuit are integrated in a single die. A source node architecture for an optical communication channel, the source node architecture comprising: a source device; a sending device; and a first sub-circuit, wherein the first sub-circuit is coupled to the transmitting device and a power source from the source device, wherein the first sub-circuit generates a first current and a second current, wherein , the first current is input to the source device to output a first electrical signal from the source device, and the second current is input to the sending device to make a first photodiode generate a first light Signal. The source node architecture of claim 13, wherein the first current flows along a current path from a drain to a source of a field effect transistor inside the source device. The source node architecture of claim 13, wherein a total current of the first current and the second current is controlled within a predetermined range. The source node architecture of claim 13, wherein the first current is controlled within a first predetermined range and the second current is controlled within a second predetermined range. The source node architecture of claim 13, wherein the first sub-circuit includes a DC-to-DC converter for converting a first voltage of the power supply to a second voltage, and the DC-to-DC converter A second sub-circuit is connected in series with the converter, wherein the second sub-circuit receives the second voltage to generate the first current and the second current. The source node architecture of claim 17, wherein the second subcircuit includes a resistor and a zener diode in parallel with the resistor, wherein a first end of the resistor and the zener diode The first end of the body is electrically connected to the first node, the second end of the resistor and the second end of the Zener diode are electrically connected to the second node, wherein the first current is connected to the first current Both currents pass through the second node. The source node architecture of claim 17, wherein the second subcircuit includes a resistor and a zener diode in parallel with the resistor, wherein a first end of the resistor and the zener diode The first end of the pole body is electrically connected to the first node, and the second end of the resistor and the second end of the Zener diode are electrically connected to the second node, wherein the first current passes through The second node is provided to the source device, and the second current is provided to the transmission device through the first node. The source node architecture of claim 19, wherein the first electrical signal is coupled to the transmitting device via a capacitor.

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