CN113872045B

CN113872045B - Optical device drive circuit, impedance matching method, optical module, and electronic apparatus

Info

Publication number: CN113872045B
Application number: CN202111022101.5A
Authority: CN
Inventors: 林永辉
Original assignee: Xiamen UX High Speed IC Co Ltd
Current assignee: Xiamen UX High Speed IC Co Ltd
Priority date: 2021-09-01
Filing date: 2021-09-01
Publication date: 2023-03-14
Anticipated expiration: 2041-09-01
Also published as: CN113872045A

Abstract

An optical device driving circuit, an impedance matching method, an optical module, and an electronic apparatus, the circuit comprising: the driving module comprises an impedance matching unit and a driving unit, the impedance matching unit is connected with the driving unit, the driving unit is used for receiving an input signal and outputting a driving signal, and the impedance matching unit is used for performing impedance matching; the energy storage module is connected between the driving module and a fixed endpoint and used for storing electric charges, and the fixed endpoint is a power supply voltage endpoint or a grounding endpoint; and the current source module comprises a current source and a current source control switch, the current source is connected with the driving unit through the current source control switch, and the current source control switch responds to the current control signal to control the current source to supply current to the driving unit. The current control signal controls the current source to supply current to the driving unit so as to control the burst working state of the optical device, and the flexibility of switching the working state of the circuit is enhanced.

Description

Optical device drive circuit, impedance matching method, optical module, and electronic apparatus

Technical Field

The present disclosure relates to the field of electronic technologies, and in particular, to an optical device driving circuit, an impedance matching method, an optical module, and an electronic apparatus.

Background

The optical module is composed of an optical device, a functional circuit, an optical interface and the like. In brief, the optical module functions in that a transmitting end converts an electrical signal into an optical signal, and a receiving end converts the optical signal into the electrical signal after the optical signal is transmitted through an optical fiber. In a high-speed optical module for optical communication, an optical device needs to be driven by a high-speed driver. One type of such drivers is a DC (direct current) coupled laser driver. The laser driver driven optics include a laser. In a passive optical network, a time division communication mode is adopted among multiple users, and rapid response to the on time and the off time of a laser is required, namely, a communication system of a rapid burst mode is required to be realized so as to improve the data transmission rate. This requires control of the burst mode operation.

Disclosure of Invention

In view of this, the present application provides an optical device driving circuit, an impedance matching method, an optical assembly and an electronic device to solve the problem that the conventional driver is lack of control over the high-speed burst operating state.

The application provides an optical device drive circuit, including: the driving module comprises an impedance matching unit and a driving unit, the impedance matching unit is connected with the driving unit, the driving unit is used for receiving an input signal and outputting a driving signal, and the impedance matching unit is used for performing impedance matching; the energy storage module is connected between the driving module and a fixed endpoint and used for storing charges, and the fixed endpoint is a power supply voltage endpoint or a grounding endpoint; the current source module comprises a current source and a current source control switch, wherein the current source is connected with the driving unit through the current source control switch, and the current source control switch responds to a current control signal to control the current source to provide current for the driving unit.

Optionally, the method further includes: the energy storage control switch is connected between the energy storage module and the driving module and responds to an energy storage control signal to control the energy storage control switch to be closed when the driving circuit is in a burst enabling working state and to be disconnected when the driving circuit is in a burst closing working state, so that the direct current working voltage at the output end of the driving module is ensured to be in a stable state.

Optionally, the driving circuit further includes a signal generating module; the signal generating module comprises a delay unit and a logic operation unit; the delay unit is used for delaying an input enable control signal for a preset time and then outputting the current control signal, and the enable control signal is used for controlling the drive circuit to carry out a burst enable working state; the logic operation unit is connected with the delay unit and used for performing logic operation on the current control signal and the enable control signal and then outputting the energy storage control signal.

Optionally, the driving circuit further includes a high-frequency channel module; one end of the high-frequency channel module is connected to the fixed end point, and the other end of the high-frequency channel module is connected to a connection node of the energy storage control switch and the impedance matching unit and is used for providing a high-frequency short-circuit channel to the fixed end point for the impedance matching unit.

Optionally, the high-frequency channel module includes a high-frequency capacitance device; one end of the high-frequency capacitor device is connected to the fixed end point, and the other end of the high-frequency capacitor device is connected to a connection node of the energy storage control switch and the impedance matching unit.

The impedance matching method of the optical device driving circuit comprises providing the optical device driving circuit, wherein the optical device driving circuit comprises an energy storage module and an energy storage control switch, one end of the energy storage module is connected with a fixed endpoint, the other end of the energy storage module is connected with the driving module through the energy storage control switch, and the fixed endpoint is a power supply voltage endpoint or a grounding endpoint; a high frequency short circuit path is provided between the fixed terminal and the driver module to achieve impedance matching of the optical device driver circuit.

Optionally, the step of providing a high-frequency short-circuit channel includes: and connecting a high-frequency capacitor device between the fixed end point and the driving module to provide a high-frequency short-circuit channel.

Optionally, the impedance matching method further includes: and providing a current control signal and an energy storage control signal, wherein the current control signal is used for controlling a current source to provide current for the driving circuit, and the energy storage control signal is used for controlling the direct-current working voltage of the output end of the driving module to be in a stable state when burst enabling and burst closing are performed.

Optionally, the step of providing the current control signal and the energy storage control signal specifically includes: delaying the enabling control signal for a preset time and then outputting the current control signal; and performing logic operation on the current control signal and the enable control signal and then outputting the energy storage signal.

An optical module comprising an optical device and said optical device driving circuit; the driving signal output by the optical device driving circuit is used for driving the optical device to emit light; the impedance matching unit is used for performing impedance matching on the output end of the optical device driving circuit and the optical device.

An electronic device includes an optical device driving circuit or includes an optical component.

According to the optical device driving circuit, the current source control switch is additionally arranged and is connected with the driving unit, and the current source is controlled to supply current to the driving unit through the current control signal so as to control the high-speed burst working state of the optical device, so that the flexibility of switching the working state of the circuit is enhanced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic diagram of a conventional driving circuit for an optical device;

FIG. 2 is a schematic diagram of an optical device driving circuit controlled by an enable control signal according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of an optical device driving circuit according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of an optical device driving circuit according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of an optical device driving circuit according to an embodiment of the present invention;

FIG. 6 is a circuit diagram of the generation of the current control signal and the energy storage control signal according to an embodiment of the present invention;

FIG. 7 is a waveform diagram of a burst enable control signal, a current control signal, and a tank control signal according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of an optical device driver circuit according to an embodiment of the present invention;

fig. 9 is a flowchart of an impedance matching method of an optical device driving circuit according to an embodiment of the present invention.

With the above figures, there are shown specific embodiments of the present application, which will be described in more detail below. These drawings and written description are not intended to limit the scope of the inventive concepts in any manner, but rather to illustrate the inventive concepts to those skilled in the art by reference to specific embodiments.

Detailed Description

The technical solutions in the embodiments of the present application are clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application. The embodiments described below and their technical features may be combined with each other without conflict.

Fig. 1 is a schematic structural diagram of a conventional driving circuit of an optical device.

The existing optical device driving circuit comprises a driving module 1, wherein the driving module 1 comprises a driving tube for outputting a driving signal to the optical device 2 according to an input data signal to control the optical device 2 to be turned on or off. The driving current source comprises a bias current source Ibias and a modulation current source Imod, and the input data signal is conducted through the control driving tube to control whether the alternating modulation current flows into the optical device 2.

Therefore, the conventional optical device driving circuit is lack of control over the high-speed burst working state, so that the working state switching of the circuit is not flexible.

In the optical device driving circuit of the burst mode, in order to realize the control of the high-speed burst operating state of the optical device, the invention provides an optical device driving circuit controlled by an enable control signal.

Referring to fig. 2, a schematic structural diagram of an optical device driving circuit controlled by an enable control signal according to an embodiment of the present invention is shown.

Like elements in comparison to fig. 1 are identified with like reference numerals.

The optical device driving circuit controlled by the burst enable control signal of the embodiment includes a driving module 1, an energy storage module 3 and a current source module 4.

The drive module 1 is connected to an external optical device 2. The driver module 1 is configured to receive an input signal and process it into a drive signal capable of driving the optical device 2, in particular, to provide the input signal to the driver module 1 through one or more input ports, and the input signal is amplified to output the drive signal. The input signal may be a single-ended signal or a differential signal, or any other form of signal. In this embodiment, the input signal is preferably a differential signal, and the differential input signal is differentially amplified to output a differential driving signal. The drive module 1 may be configured to include one or more impedance matching units, which are impedance matching devices or networks, to match impedances, such as from an impedance at the input and/or to the output of the optical device 2. The impedance matching device may include one or more resistors, inductors, capacitors, active devices, or a combination of one or more of these devices. Proper impedance matching ensures maximum signal transfer efficiency and reduces signal reflections at the output, thereby improving circuit performance, bandwidth and data transfer rate.

The optical device 2 may comprise any device capable of generating an optical signal with or without complete or embedded traces including, but not limited to, one or more lasers, LEDs (light emitting diodes), optical modulators, or any other type of optical signal generator or modulator. The system application or operating environment for fig. 2 can be an optical communication system, a projection system, and any other application or environment that utilizes optical signals.

And the energy storage module 3 is connected between the driving module 1 and a fixed endpoint, and is used for storing charges, wherein the fixed endpoint is a power supply voltage endpoint or a grounding endpoint, and an alternating current short circuit path from a power supply or ground is formed through the energy storage module 3. The energy storage module 3 is a charge storage device, which may be any device that stores or supplements a charge, including but not limited to a capacitor, a passive/active device such as a transistor, a FET (field effect transistor), a MOSFET (metal oxide semiconductor field effect transistor)), or any active circuit.

The current source module 4 comprises a current source 41 and a current source control switch 42, wherein the current source 41 is connected to the driving unit through the current source control switch 42, and the current source control switch 42 is responsive to a current control signal to control the current source 41 to supply current to the driving unit. The current control signal may be provided by an external controller or may be generated by an internal circuit, and the enable control signal BEN _ IN may be directly used as the current control signal or may be delayed to be used as the current control signal.

IN the optical device driving circuit of the present embodiment, when the enable control signal BEN _ IN is at the first level, the current source control switch 42 is turned on, the current source 41 supplies current to the optical device driving circuit, the driving circuit enters the burst enable operation state, and the optical device 2 emits light normally. When the enable control signal BEN _ IN is at the second level, the current source control switch 42 is turned off, the current source 41 stops supplying current to the optical device driving circuit, the driving circuit enters the burst-off operating state, and the optical device 2 does not emit light. IN order to respond quickly to the turning on of the optical device 2 and the turning off of the optical device 2, the optical device driving circuit can realize the quick switching of the burst mode by enabling the control signal BEN _ IN, and the flexibility of the burst mode switching of the circuit is improved. The first level may be a high level or a low level, and the corresponding second level may be a low level or a high level.

Referring to fig. 3, a schematic structural diagram of an optical device driving circuit according to an embodiment of the invention is shown.

The driving module 1 of this embodiment includes an impedance matching unit and a driving unit 11, the impedance matching unit includes impedance matching resistors R0 and R1, since the driving unit 11 is usually connected to the optical device 2 through a wire bonding and a PCB (printed circuit board) routing, a high-speed signal may be obviously reflected to the optical device 2 through the wire bonding and the PCB routing, which causes signal distortion. The impedance matching resistor R0 and the resistor R1 are thus terminated at the output of the driving unit 11 to improve the reflected impedance matching resistance. Specifically, the resistors R0 and R1 are connected between the power supply voltage Vdd and the driving unit 11 to perform impedance matching on the output terminal of the driving unit 11. The driving unit 11 is configured to receive an input signal and output a driving signal according to the input signal, wherein the driving signal is used for driving the optical device 2 to emit light.

And the energy storage module 3 is connected between one end of the impedance matching resistor R1 and a fixed end point, and is used for establishing an alternating current short circuit path, wherein the fixed end point is a power supply voltage Vdd or a ground end point. The fixed terminal in this embodiment is preferably the supply voltage Vdd.

In this embodiment, the energy storage module 3 is an energy storage capacitor C0, the capacitor C0 is a large capacitor, one end of the capacitor C0 is connected to the power voltage Vdd, the other end of the capacitor C0 is connected to one end of the driving unit 11 through the resistor R1, and the capacitor C0 forms an ac short circuit path from the resistor R1 to the power voltage Vdd.

In this embodiment, the current source module 4 includes two current sources, one of which provides an ac modulation current to the driving module 1, and the other of which provides a bias current to the optical device 2. Specifically, the current source comprises a modulation current source Imod and a bias current source Ibias; the current source control switch comprises K1 and K2, the modulation current source Imod and the bias current source Ibias are known components, which are not discussed in detail. The current source control switch K1 is connected between the modulation current source Imod and the ground IN series, the current source control switch K2 is connected between the bias current source Ibias and the ground IN series, the current source control switches K1 and K2 are both controlled by an enable control signal BEN _ IN, and the enable control signal BEN _ IN responds to a circuit burst-on mode or a burst-off mode by opening or closing the current source control switches K1 and K2. IN the burst-on mode IN this embodiment, when the burst enable control signal BEN _ IN is at a high level, the current source control switches K1 and K2 are turned on, the operating state of the optical device 2 is similar to that of fig. 1, and the optical device 2 emits light normally. When the burst off is performed, the burst enable control signal BEN _ IN is at a low level, the current source control switches K1 and K2 are turned off, the modulation current and the bias current flowing through the optical device 2 are completely turned off, and the optical device 2 stops emitting light. IN other alternative embodiments, the current source control switches K1 and K2 are turned on when the burst enable control signal BEN _ IN is at a low level, and the current source control switches K1 and K2 are turned off when the burst enable control signal BEN _ IN is at a high level. The current source control switches K1 and K2 may be controlled by one or more control signals.

In an alternative embodiment, the current source in the current source module 4 may only include a modulation current source Imod, and the current source Imod is connected to the driving module 1 through a current source control switch to control the current source to supply current to the driving module. The control signal BEN _ IN may control the operating mode of the circuit by controlling a current source. The current control signal may be a burst enable control signal BEN _ IN, or may be another type of control signal.

The circuit in fig. 3 operates as follows: during the burst-on mode, the switches K1 and K2 are controlled to be closed IN response to the burst enable control signal BEN _ IN, and the capacitor C0 charges and stores charge. The capacitor C0 also acts to prevent a direct current from flowing from the power supply voltage Vdd to the driving unit 11, reducing power consumption by not supplying a current to the driving unit. When the control switches K1 and K2 are turned off, an ac short circuit path from the power supply voltage Vdd to the driving module 1 is established so that the driving module 1 operates normally. The charge maintained on capacitor C0 is used to establish a fast response time when re-establishing the signal during a subsequent transmit cycle, and thus circuit performance may be improved. If the charge remaining on the capacitor C0 is lost, at the beginning of a subsequent transmission session, the circuit may charge parasitic capacitors or other circuit elements in the circuit before transmission begins, causing a transmission delay that does not respond quickly to the on or off time of the optical device 2.

The optical device driving circuit of this embodiment, through the current source control switch, the current source control switch responds to the current control signal in order to control the current source provides the electric current for the drive unit, realizes that high speed burst operating state controls, and the circuit operating state switches flexibly. By storing charge through the storage capacitor, transmission delay can be eliminated, and the on or off time of the optical device 2 can be responded to quickly.

In some applications, where the burst enable time and the off time of the optical device 2 are required to be less than 12.8ns (nanoseconds), i.e., the on or off time is required to be less than 12.8ns, the time from the start of operation to the stable operation of the optical device 2 is required, in which case the optical device driving circuit of fig. 2 has the following problems:

the resistors R0 and R1 are usually about 25 ohms, the optical device driving circuit needs to transmit signals of various rates, including long-connection "0" or long-connection "1" signals, and to ensure that the signals are not distorted, this requires that the capacitor C0 should reach a relatively small ac impedance, the capacitance should reach more than several hundred pF (picofarad), the capacitor C0 with a capacitance of more than several hundred pF should reach complete stability, the charging time should be at least more than tens of ns, which obviously cannot meet the requirement that the burst enable time and the off time are less than 12.8 ns.

In order to solve the problem of the optical device driving circuit of fig. 3, the present invention further improves the optical device driving circuit of fig. 3.

Referring to fig. 4, a schematic structural diagram of an optical device driving circuit according to an embodiment of the invention is shown.

Like elements in comparison to fig. 3 are identified with like reference numerals.

The optical device driving circuit of the present embodiment includes a storage control switch K3 connected between the energy storage module 2 and the driving module 1, and the storage control switch K3 may be any type of switch, passive or active, and may be controlled by one or more control signals.

In this embodiment, the energy storage control switch K3 is connected in series between the capacitor C0 and the resistor R1, and in other optional embodiments, the energy storage control switch K3 may also be connected in series between the capacitor C0 and the power voltage Vdd or between the driving module 1 and the resistor R1. When the optical device driving circuit is in a burst enabling working state, the energy storage control switch K3 is closed, and the capacitor C0 is in a charging state; when the optical device driving circuit is in burst closing, the energy storage control switch K3 is switched off, and the capacitor C0 is in a holding state. Due to the existence of the energy storage control switch K3, the direct current working voltage at the output end of the driving module 1 can be ensured to be in a stable state when burst enabling and burst closing are carried out, so that the burst enabling and closing time of the optical device 2 can not be influenced, and the problems that in the figure 3, because the capacitance value of the capacitor C0 is more than hundreds of pF, the capacitor C0 is completely stable, the charging time is at least more than tens of ns, and the requirements that the burst enabling time and the closing time are less than 12.8ns can not be met are solved.

However, the optical device driving circuit in fig. 4 has the following problems: in a high-speed optical device driving circuit, the resistances of the resistors R1 and R2 need to be small, usually about 25 ohms, and the on resistance of the energy storage control switch K3 needs to be much smaller than the resistance of the resistor R2, so that the impedance characteristic from the resistor R2 to a power supply cannot be affected. In an integrated circuit, a control switch far smaller than 25 ohms is to be implemented, and the parasitic parameter of the control switch at high frequency is small, and the high frequency performance is good, which is difficult, so that the high frequency resistance of the energy storage control switch K3 in fig. 4 is large due to the high frequency parasitic parameter, and the impedance discontinuity occurs due to the introduction of the energy storage control switch K3 in a path from the resistor R1 to the energy storage control switch K3 to the capacitor C0 to the power supply, which leads to the reduction of the high frequency performance of the optical device driving circuit.

In order to further solve the problem that the high-frequency performance of the optical device driving circuit in fig. 4 is reduced due to impedance discontinuity caused by the introduction of the energy storage control switch K3, the invention further improves the optical device driving circuit in fig. 4.

Referring to fig. 5, a schematic structural diagram of an optical device driving circuit according to an embodiment of the invention is shown.

Like elements in comparison to fig. 4 are identified with like reference numerals.

In the optical device driving circuit of the present embodiment, the driving module 1 includes transistors M1, M2, M3, and M4. M1 and M2 form a pair of switching transistors, the gates of M1 and M2 are respectively input to differential pairs INP and INN, the gates of M1 and M2 are input terminals of the driving module 1, and the differential pairs INP and INN come from other elements. The sources of M1 and M2 receive the modulation current source Imod, the drain of M1 is connected to the source of the transistor M3, the drain of M2 is connected to the source of the transistor M4, the gate of M3 receives the voltage Vcos2, the gate of M4 receives the voltage Vcos1, and the voltage Vcos1 and the voltage Vcos2 are provided by an external circuit.

The impedance matching unit comprises capacitors R0 and R1, the drain electrode of M4 is connected with one end of a resistor R0, and the other end of the resistor R0 is connected with a power supply voltage Vdd. The drain electrode of the M3 is connected with one end of the resistor R1, the other end of the resistor R1 is respectively connected with one end of the energy storage control switch K3, the other end of the K3 is connected with one end of the capacitor C0, and the other end of the capacitor C0 is connected with a power supply voltage Vdd.

The optical device 2 includes a light emitting element D0. Inductors L0 and L1 provide an ac high resistance, dc low resistance path. One end of L0 is connected to the power supply voltage Vdd, the other end is connected to the anode terminal of the light emitting element D0, and the cathode terminal of D0 is connected to one end of the inductor L1. The other end of L1 is connected with a bias current source Ibias which is grounded through a switch K2. The anode terminal of the light emitting element D0 is also connected to the drain of the transistor M4 to form a node outN, and the cathode terminal of the light emitting element D0 is also connected to the connection node outP of the resistor R1 and the switch K3.

The transistors M3 and M4 are used to prevent the signals of the nodes outP and outN from being too large and the transistors M1 and M2 from breaking down, and also to balance the bias voltages of the transistors M1 and M2 when the voltages between the nodes outP and outN are not matched. In other embodiments, the transistors M3 and M4 may be omitted or stacked in multiple stages. M1-M4 may use active devices other than transistors. The differential pair INP and INN may be configured as or instead of an emitter follower generator, a modulation circuit, or any circuit that provides a modulation signal to the optical device.

The driving module 1 receives an externally input differential pair INN and INNP and provides a driving signal to the optical device 2 via the sources of the transistors M3 and M4. The impedance matching resistors R1 and R0 are used to match the impedance of the output of the driving module 1 and the input of the optical device 2. Capacitor C0 provides an ac path.

Light-emitting element D0 generates an optical signal and may comprise one or more lasers, LEDs, or any other element that generates an optical signal. The inductances L0 and L1 influence the time constant of the burst on/burst off transitions, which depends on the values of the inductors L0 and L1.

The optical device driving circuit of the present embodiment further includes a high-frequency channel module 5. In other optional embodiments, one end of the high-frequency channel module 5 is connected to the power supply voltage Vdd, in other optional embodiments, one end of the high-frequency channel module 5 may also be connected to ground, and the other end of the high-frequency channel module 5 is connected to a connection node outP of the energy storage control switch K3 and the impedance matching unit, and is configured to provide a high-frequency short-circuit channel to the power supply voltage Vdd or ground to the impedance matching unit, so that the high-frequency performance of the optical device driving circuit is not affected by the impedance of the energy storage control switch K3. In this embodiment, the high-frequency channel module includes a high-frequency capacitor device C1, where the high-frequency capacitor device C1 is composed of a passive element, an active device, and a passive network, and includes a CBB (polypropylene) capacitor, a mica capacitor (such as a gold or silver mica capacitor), a monolithic capacitor, and the like.

In the optical device driving circuit of the present embodiment, the current source control switches K1 and K2 are controlled by a current control signal BEN. When the burst enable is performed, the current signals BEN control the switches K1 and K2 to be in the closed state, the currents of the current sources Imod and Ibias are in the on state, and the light emitting element D0 is in the normal light emitting state. When the light emitting unit D0 is in the non-light emitting state, the switches K1 and K2 controlled by the current control signal BEN are in the off state, the currents of the current sources Imod and Ibias are in the off state, and the current control signal BEN controls the switches K1 and K2.

Referring to fig. 6, a circuit diagram of generating a current control signal and a tank control signal according to an embodiment of the invention is shown.

The optical device driving circuit of the present embodiment further includes a signal generating module; the signal generation module comprises a delay unit 6 and a logical operation unit 7.

The delay unit 6 is configured to delay an input enable control signal BEN _ IN by a preset time and then output the current control signal BEN, where the enable control signal is used to control the driving circuit to perform a burst enable operation state.

The logic operation unit 7 is connected to the delay unit 6, and configured to perform logic operation on the current control signal BEN and the enable control signal BEN _ IN, and then output the energy storage control signal S1.

Specifically, the burst enable control signal BEN _ IN is delayed by the delay unit 6 and then outputs the current control signal BEN. The delay unit 6 includes a buffer, a counter, or other circuits that can implement a delay function. The current control signal BEN is delayed by the delay unit 6 and then input to the first input end of the logic operation unit 7, the burst enable control signal BEN _ IN is input to the second input end of the logic operation unit 7, and the logic operation unit 7 outputs the energy storage control signal S1. The logical operation unit 7 in this embodiment is a logical and operation unit.

Referring to fig. 7, waveform diagrams of the burst enable control signal, the current control signal and the energy storage control signal according to an embodiment of the present invention are shown.

IN fig. 7, the rising edge of the burst enable control signal BEN _ IN is the earliest and the falling edge is the latest. The rising edge of the energy storage control signal S1 of the energy storage control switch K3 is delayed for a period of time after the rising edge of the current control signal BEN, and the falling edge of S1 is advanced for a period of time before the falling edge of the current control signal BEN. Therefore, the energy storage capacitor C0 can be ensured to perform charge sampling work during burst enabling, and the unstable state of the circuit during burst enabling and closing is avoided.

The coupling capacitor from the resistor R1 to the power supply voltage Vdd consists of a large capacitor C0 and a small capacitor C1. The small capacitor C1 is directly connected to a power supply voltage Vdd through the resistor R1, and a high-frequency short-circuit channel from the resistor R1 to a power supply is provided, so that the high-frequency performance of the circuit is not influenced by the impedance of the energy storage control switch K3. Because the capacitance value of the capacitor C1 is smaller, the charging and discharging time is faster, and the influence on the response time of the optical device during burst enabling and shutting down is small. The large capacitor C0 provides an ac path for a relatively low frequency long-on "0" or long-on "1" signal. The relatively low frequency signal is less impedance sensitive and tolerant of the impedance discontinuity introduced by the tank control switch K3. Therefore, a high-frequency path is provided by the high-frequency capacitor C1, a relatively low-frequency path is provided by the energy storage control switch K3 and the energy storage capacitor C0, a proper impedance matching path for various frequency signals can be met, and response time of burst enabling and shutting down can be met.

Referring to fig. 8, a schematic structural diagram of an optical device driving circuit according to an embodiment of the invention is shown.

Like elements in comparison to fig. 5 are identified with like reference numerals.

In the optical device driving circuit of the present embodiment, one end of the energy storage capacitor C0 and one end of the high-frequency capacitor C1 are both connected to ground. The small capacitor C1 is directly connected to the ground through the resistor R1, and a high-frequency short-circuit channel from the resistor R1 to the ground is provided, so that the high-frequency performance of the circuit is not influenced by the impedance of the energy storage control switch K3. Because the capacitance value of the capacitor C1 is smaller, the charging and discharging time is faster, and the influence on the response time of the optical device during burst enabling and shutting down is small. The large capacitance C0 provides an AC path for the relatively low frequency long link "0" or long link "1" signal. The relatively low frequency signal is less impedance sensitive and tolerant of the impedance discontinuity introduced by the tank control switch K3. Therefore, a high-frequency path is provided through the high-frequency capacitor C1, the energy storage control switch K3 and the energy storage capacitor C0 provide a relatively low-frequency path, the energy storage control switch K3 is switched on during burst enabling, a high-frequency signal is coupled to the ground through the high-frequency capacitor C1, a low-frequency signal is coupled to the ground through the energy storage control switch K3 and the energy storage capacitor C0, the quick response time of burst enabling and switching off can be achieved, and the high-frequency performance of the circuit is improved.

It can be seen that, in the optical device driving circuit of this embodiment, a small capacitor, i.e., the high-frequency capacitor C1, is added to the impedance matching circuit to implement a high-frequency path, and an energy storage control switch and a large capacitor, i.e., the energy storage capacitor C0, are connected in series.

The optical device driving circuit of the embodiment realizes different coupling paths of low-frequency and high-frequency signals through the large capacitor and the small capacitor, can improve the influence of the impedance of the energy storage control switch on the high-frequency signals, and realizes high-quality transmission of the high-frequency signals.

The invention also provides an impedance matching method of the optical device driving circuit.

Referring to fig. 9, a flowchart of an impedance matching method of an optical device driving circuit according to an embodiment of the invention is shown.

The impedance matching method of the optical device driving circuit of the present embodiment includes the steps of:

the method comprises the following steps of S1, providing an optical device driving circuit, wherein the optical device driving circuit comprises an energy storage module and an energy storage control switch, one end of the energy storage module is connected with a fixed endpoint, the other end of the energy storage module is connected with the driving module through the energy storage control switch, and the fixed endpoint is a power supply voltage endpoint or a grounding endpoint.

Specifically, as shown in fig. 5, the driving module 1 includes transistors M1, M2, M3, and M4, the impedance matching unit includes capacitors R0 and R1, the energy storage module includes a capacitor C0, and the energy storage control switch includes an energy storage control switch K3. M1 and M2 form a pair of switching transistors, and the gates of M1 and M2 are respectively input to differential pairs INP and INN, which can be considered as input terminals of the driving module 1, and INP and INN are derived from other components. The sources of M1 and M2 receive the modulation current source Imod, the drain of M1 is connected to the source of the transistor M3, the drain of M2 is connected to the source of the transistor M4, the gate of M3 receives the voltage Vcos2, and the gate of M4 receives the voltage Vcos 1. The drain of M4 is connected to one end of a resistor R0, and the other end of the resistor R0 is connected to a power supply voltage Vdd. The drain electrode of the M3 is connected with one end of the resistor R1, the other end of the resistor R1 is respectively connected with one end of the energy storage control switch K3, the other end of the K3 is connected with one end of the capacitor C0, and the other end of the capacitor C0 is connected with the power supply voltage Vdd. The transistors M3 and M4 are used to prevent the signals of the nodes outP and outN from being too large and the transistors M1 and M2 from breaking down, and also to balance the bias voltages of the transistors M1 and M2 when the voltages between the nodes outP and outN are not matched. In other embodiments, the transistors M3 and M4 may be omitted or stacked in multiple stages. M1-M4 may use active devices other than transistors. The differential pair INP and INN may be configured as or instead of an emitter follower generator, a modulation circuit, or any circuit that provides a modulation signal to an optical device.

The driving module 1 receives an externally input differential pair INN and INNP and provides a driving signal to the optical device 2 via the sources of the transistors M3 and M4. The impedance matching resistors R1 and R0 are used to match the impedance of the output terminal of the driving module 1 and the input terminal of the optical device 2. Capacitor C0 provides an ac path.

And S2, providing a high-frequency short-circuit channel between the fixed end point and the driving module to realize impedance matching of the optical device driving circuit.

Specifically, a high-frequency capacitor device is connected between the impedance matching unit and the fixed terminal for providing a high-frequency short-circuit path to the fixed terminal to the impedance matching unit. The fixed end point is a power supply voltage Vdd, the high-frequency channel module comprises a high-frequency capacitor device C1, and the high-frequency capacitor device C1 consists of a passive element, an active device and a passive network and comprises a CBB (polypropylene) capacitor, a mica capacitor (such as a gold or silver mica capacitor), a monolithic capacitor and the like. In other alternative embodiments, other components may be provided according to actual needs to provide a high-frequency path for the impedance matching unit. In the circuit shown in fig. 5, the coupling capacitor of the resistor R1 to the power supply voltage Vdd is composed of a large capacitor C0 and a small capacitor C1. The small capacitor C1 is directly connected to a power supply voltage Vdd through the resistor R1, and a high-frequency short-circuit channel from the resistor R1 to a power supply is provided, so that the high-frequency performance of the circuit is not influenced by the impedance of the energy storage control switch K3. Because the capacitance value of the capacitor C1 is smaller, the charging and discharging time is faster, and the influence on the response time of the optical device during burst enabling and shutting down is small. The large capacitor C0 provides an ac path for a relatively low frequency long-on "0" or long-on "1" signal. The relatively low frequency signal is less impedance sensitive and tolerant of the impedance discontinuity introduced by the tank control switch K3. Therefore, a high-frequency path is provided by the high-frequency capacitor C1, a relatively low-frequency path is provided by the energy storage control switch K3 and the energy storage capacitor C0, a proper impedance matching path for various frequency signals can be met, and response time of burst enabling and shutting down can be met.

Or in the circuit shown in fig. 8, one end of the energy storage capacitor C0 and one end of the high-frequency capacitor C1 are both connected to ground. Because the capacitance value of the capacitor C1 is smaller, the charging and discharging time is faster, and the influence on the response time of the optical device during burst enabling and shutting down is small. The large capacitor C0 provides an ac path for a relatively low frequency long-on "0" or long-on "1" signal. The relatively low frequency signal is less impedance sensitive and tolerant of the impedance discontinuity introduced by the tank control switch K3. Therefore, a high-frequency path is provided through the high-frequency capacitor C1, the energy storage control switch K3 and the energy storage capacitor C0 provide a relatively low-frequency path, the energy storage control switch K3 is switched on during burst enabling, a high-frequency signal is coupled to the ground through the high-frequency capacitor C1, a low-frequency signal is coupled to the ground through the energy storage control switch K3 and the energy storage capacitor C0, the quick response time of burst enabling and switching off can be achieved, and the high-frequency performance of the circuit is improved.

In other alternative embodiments, other ways of providing a high frequency path may be provided to achieve impedance matching of the optical device driver circuit.

In an optional embodiment, the impedance matching method of the optical device driving circuit further includes: and providing a current control signal and an energy storage control signal, wherein the current control signal is used for controlling the current source to provide current for the driving module, and the energy storage control signal is used for controlling the direct-current working voltage at the output end of the driving module to be in a stable state when burst enabling and burst closing are performed.

In particular, the current control signal and the tank control signal are generated by a controller, including but not limited to any type of controller, including but not limited to control logic, an ASIC (application specific integrated circuit), a processor, a delay state machine, or any combination thereof. The controller provides the current control signal and the energy storage control signal to the optical device driving circuit through a timer or receives a trigger signal, or provides the current control signal through the controller, and generates the energy storage control signal according to the current control signal through the delay circuit.

Optionally, the enable control signal is delayed for a preset time and then the current control signal is provided; for example, the enable control signal is subjected to a preset time delay through a delay device, such as a hardware circuit of a buffer, a counter, or the like, or the preset time delay is performed through a controller, and the delayed enable control signal is used as a current control signal.

And providing the energy storage signal after performing logical operation on the current control signal and the enable control signal. And inputting the current control signal and the enable control signal into a logic operation circuit to carry out logic operation so as to obtain the energy storage signal, or inputting the current control signal and the enable control signal into a controller to carry out logic operation so as to obtain the energy storage signal. The logical operation includes an and operation. In this embodiment, the current control signal and the enable control signal are anded to provide the energy storage signal. In other embodiments, the type of operation may be selected based on the actual application.

According to the impedance matching method of the optical device driving circuit, the high-frequency signal is coupled to the power supply or the ground through the high-frequency capacitor, the low-frequency signal is coupled to the power supply or the ground through the energy storage control switch and the energy storage capacitor, so that the high-frequency signal and the low-frequency signal both have a proper coupling path, the influence of the impedance of the energy storage control switch on the high-frequency signal is improved, the high-quality transmission of the high-frequency signal is realized, and meanwhile, the response time of rapid burst enabling and closing can be realized.

The present invention also provides an optical assembly comprising an optical device and the optical device driving circuit described above; the driving signal output by the optical device driving circuit is used for driving the optical device to emit light; the impedance matching unit is used for performing impedance matching on the output end of the optical device driving circuit and the optical device. The optical component is a high-speed optical module, and the influence of the impedance of the energy storage control switch on the high-frequency signal can be improved through the optical device driving circuit, so that the high-quality transmission of the high-frequency signal is realized.

The present invention also provides an electronic apparatus including the above optical device driving circuit, or, an optical module. The electronic equipment comprises various intelligent terminals such as mobile phones, computers and various communication equipment, and the influence of the impedance of the energy storage control switch on the high-frequency signal can be improved through the optical device driving circuit, so that the high-quality transmission of the high-frequency signal is realized.

The above description is only an embodiment of the present application, and not intended to limit the scope of the present application, and all equivalent structures or equivalent processes, such as combinations of technical features between various embodiments, or direct or indirect applications in other related technical fields, which are made by using the contents of the present specification and the accompanying drawings, are all included in the scope of the present application.

Claims

1. An optical device driving circuit, comprising:

the driving module comprises an impedance matching unit and a driving unit, the impedance matching unit is connected with the driving unit, the driving unit is used for receiving an input signal and outputting a driving signal, and the impedance matching unit is used for performing impedance matching;

the energy storage module is connected between the driving module and a fixed endpoint and used for storing electric charges, and the fixed endpoint is a power supply voltage endpoint or a grounding endpoint;

the current source module comprises a current source and a current source control switch, the current source is connected with the driving unit through the current source control switch, and the current source control switch responds to a current control signal to control the current source to provide current for the driving unit;

the signal generation module comprises a delay unit, the delay unit is used for delaying an input enable control signal for a preset time and then outputting the current control signal, and the enable control signal is used for controlling the drive circuit to carry out a burst enable working state.

2. The optical device driving circuit according to claim 1, further comprising:

the energy storage control switch is connected between the energy storage module and the driving module and responds to an energy storage control signal to control the energy storage control switch to be closed when the driving circuit is in a burst enabling working state and to be disconnected when the driving circuit is in a burst closing working state, so that the direct current working voltage at the output end of the driving module is ensured to be in a stable state.

3. The optical device driving circuit according to claim 2, wherein the signal generating module further includes a logical operation unit; the logic operation unit is connected with the delay unit and is used for performing logic operation on the current control signal and the enable control signal and then outputting the energy storage control signal.

4. An optical device driving circuit according to claim 2 or 3, wherein the driving circuit further comprises a high-frequency channel module;

one end of the high-frequency channel module is connected to the fixed end point, and the other end of the high-frequency channel module is connected to a connection node of the energy storage control switch and the impedance matching unit and is used for providing a high-frequency short-circuit channel to the fixed end point for the impedance matching unit.

5. The optical device driving circuit according to claim 4, wherein the high-frequency channel module includes a high-frequency capacitance device;

one end of the high-frequency capacitor device is connected to the fixed end point, and the other end of the high-frequency capacitor device is connected to a connection node of the energy storage control switch and the impedance matching unit.

6. An impedance matching method of an optical device driving circuit, comprising:

providing an optical device driving circuit as claimed in any one of claims 1 to 5;

a high frequency short circuit path is provided between the fixed terminal and the driver module to achieve impedance matching of the optical device driver circuit.

7. The impedance matching method of an optical device driving circuit according to claim 6, wherein said step of providing a high-frequency short-circuit path comprises:

and connecting a high-frequency capacitance device between the fixed end point and the driving module to provide a high-frequency short-circuit channel.

8. The impedance matching method of an optical device driving circuit according to claim 6 or 7, further comprising:

and providing a current control signal and an energy storage control signal, wherein the current control signal is used for controlling a current source to provide current for the driving circuit, and the energy storage control signal is used for controlling the direct-current working voltage at the output end of the driving module to be in a stable state when burst enabling and burst closing are performed.

9. The method of impedance matching for an optical device driver circuit as claimed in claim 8, wherein said step of providing a current control signal and a storage control signal comprises:

delaying the enabling control signal for a preset time and then outputting the current control signal;

and performing logical operation on the current control signal and the enable control signal and then outputting the energy storage control signal.

10. An optical module comprising an optical device and an optical device driving circuit according to any one of claims 1 to 5;

the driving signal output by the optical device driving circuit is used for driving the optical device to emit light;

the impedance matching unit is used for performing impedance matching on the output end of the optical device driving circuit and the optical device.

11. An electronic device characterized by comprising the optical device driving circuit according to any one of claims 1 to 5.