CN217085336U

CN217085336U - Low-power consumption CWDM optical module

Info

Publication number: CN217085336U
Application number: CN202220732163.9U
Authority: CN
Inventors: 贺建龙; 谢怀堂
Original assignee: Miyang Mingpu Electronics Co ltd; Dongguan Mentech Optical and Magnetic Co Ltd
Current assignee: Miyang Mingpu Electronics Co ltd; Dongguan Mentech Optical and Magnetic Co Ltd
Priority date: 2022-03-31
Filing date: 2022-03-31
Publication date: 2022-07-29
Anticipated expiration: 2032-03-31

Abstract

The utility model discloses a low-power consumption CWDM optical module, which comprises a control unit, a heating circuit, a laser driver and a laser; the laser comprises a heating component; the control unit outputs a PWM signal to the heating circuit; the heating circuit outputs corresponding heating voltage to the heating assembly after receiving the PWM signal so as to heat the heating assembly; the heating circuit comprises a PMOS tube, a freewheeling diode, a magnetic bead, a first resistor, a second resistor, a first inductor, a first capacitor and a second capacitor. The utility model discloses a change heating circuit to let the control unit output PWM signal give heating element, make heating circuit can export corresponding heating voltage after receiving the PWM signal and give heating element, realize not only having promoted heating circuit's conversion efficiency to heating element's heating, with the heating efficiency who promotes heating circuit, reduced the heating consumption moreover, thereby saved the heating cost.

Description

Low-power consumption CWDM optical module

Technical Field

The utility model relates to an optical communication technical field especially relates to a low-power consumption CWDM optical module.

Background

With the development of a 5G bearer network, in an optical communication network, the importance of the operation type factor of an optical module is more and more prominent, for example, the mainstream optical module in the market is gradually switched from a 25G rate to a 10G rate, and for that reason, the power consumption of the optical module is a great promoting factor. The power consumption of the 25G-rate industrial optical module is about 2W, the power consumption of the 10G-rate industrial optical module is generally within 1.5W, and compared with the power consumption, 25% of operation power consumption can be saved, and the power consumption is sacrificed, but the power consumption is relatively acceptable.

At present, in order to meet the Wavelength requirement of an industrial CWDM (Coarse Wavelength Division Multiplexer) optical module, a heating mode is usually adopted to expand the working temperature range. The traditional heating methods mainly include two types, one of which is temperature regulation by using a TEC (Thermo Electric Cooler), and is generally used in products with low cost; another method is to add a heating resistor inside a TOSA (Transmitter Optical subassembly), and this solution using the heating resistor is widely used in industrial CWDM Optical modules due to low cost.

However, the existing scheme using the heating resistor uses the main power supply of the optical module, and the control mode mainly uses DAC analog regulation or mainly uses sectional regulation, which has the following disadvantages:

a first disadvantage is that the control of the stepwise regulation is generally bounded by a certain temperature, i.e. below which the heating circuit is switched on, so that the temperature increases abruptly by a constant value, so that there is a discontinuity in the wavelength and the power consumption around this temperature point.

A second disadvantage is that different heating resistor designs have slightly different corresponding heating circuits. For example, in patent publication No. CN112255741A (a 25G CWDM optical module based on unidirectional heating), the heating voltage needs to be increased by 3.3-5V to supply heat, and at this time, a special Boost integrated chip needs to be used, the heating resistance is relatively large, and the whole circuit is relatively complex, which brings about a certain cost increase and additional power consumption.

The third disadvantage is that, for example, in the patent publication CN208128255U (an ultra-low temperature optical module), the DAC of the MCU is used for controlling the DAC, although the DAC is gradually changed, most of the power consumption of the heating circuit is consumed by the analog adjusting tube. For example, when the heating resistance is 15 Ω, typically-20 degrees, the heating power consumption is 0.3W, the current is 141mA, the voltage of the heating resistance is 2.1V, the efficiency of the power consumption is 64%, the extra useless power consumption of 0.166W is mainly dissipated in the analog part regulating tube, and when the heating resistance becomes lower, the dissipated power in the analog regulating tube for adjusting and controlling becomes larger.

A fourth disadvantage is that the heating resistor is disposed at various positions in the optical module, for example, the heating resistor is disposed inside the TO (Transistor Outline) or on the flexible board. These heating portions are external heat sources for the Laser, and the temperature of the LD (Laser Diode) is changed by heating the resistor. The efficiency of this heat transfer is low, which results in high power consumption and low yield of the product.

The fifth disadvantage is that the power consumption of the current heating type industrial optical module is about 0.5-1W larger than that of the corresponding unheated optical module, and the increased power consumption and cost are not very beneficial to the large-scale application of the heating type industrial optical module.

Therefore, it is necessary to provide a new optical module heating method with low power consumption and an optical module with low power consumption.

The above information is given as background information only to aid in understanding the present disclosure, and no determination or admission is made as to whether any of the above is available as prior art against the present disclosure.

SUMMERY OF THE UTILITY MODEL

The utility model provides a low-power consumption CWDM optical module to solve the not enough of prior art.

In order to achieve the above object, the present invention provides the following technical solutions:

a low-power consumption CWDM optical module comprises a control unit, a heating circuit, a laser driver and a laser; wherein the content of the first and second substances,

the laser driver is connected with the laser;

the laser comprises a heating component;

the control unit is connected with the heating circuit and used for outputting a PWM signal to the heating circuit;

the heating circuit is connected with the heating assembly and used for outputting corresponding heating voltage to the heating assembly after receiving the PWM signal so as to heat the heating assembly;

the heating circuit comprises a PMOS (P-channel metal oxide semiconductor) tube, a freewheeling diode, a magnetic bead, a first resistor, a second resistor, a first inductor, a first capacitor and a second capacitor;

the grid electrode of the PMOS tube is connected with one end of the first resistor, the source electrode of the PMOS tube is connected with one end of the second resistor, and the drain electrode of the PMOS tube is connected with one end of the first inductor;

the other end of the first resistor is connected with the control unit;

the other end of the second resistor is connected between the grid electrode of the PMOS tube and the first resistor;

the other end of the first inductor is connected with the heating assembly;

one end of the second capacitor is connected between the source electrode of the PMOS tube and the second resistor, and the other end of the second capacitor is grounded;

the anode of the freewheeling diode is connected between the second capacitor and the ground, and the cathode of the freewheeling diode is connected between the drain of the PMOS tube and the first inductor;

one end of the magnetic bead is connected between the source electrode of the PMOS tube and the second resistor;

one end of the first capacitor is connected between the first inductor and the heating assembly, and the other end of the first capacitor is grounded.

Further, in the low-power CWDM optical module, the laser further includes a TO base, a ceramic circuit board, a sector post, a ground pin, a laser chip positive pin, a laser chip negative pin, and a heating terminal positive pin;

the TO base is electrically connected with the grounding pin;

the laser chip positive pin, the laser chip negative pin and the heating terminal positive pin are all arranged on the TO base and penetrate through the top surface and the bottom surface of the TO base;

the fan-shaped column is arranged on the top surface of the TO base and is electrically connected with the TO base;

the back surface of the ceramic circuit substrate is electrically connected with the plane side surface of the fan-shaped column;

the heating assembly comprises a first heating terminal, a first heating resistor and a second heating resistor, the first heating terminal, the first heating resistor and the second heating resistor are arranged on the front surface of the ceramic circuit substrate, and the front surface of the ceramic circuit substrate is also provided with a laser chip, a negative conducting plate, a positive conducting plate and a ground hole;

the negative electrode conducting strip and the positive electrode conducting strip are positioned on two opposite sides of the laser chip;

the first heating terminal, the first heating resistor, the ground hole and the second heating resistor are sequentially arranged around the negative conducting plate, the laser chip and the positive conducting plate so as to surround the negative conducting plate, the laser chip and the positive conducting plate;

the negative pin of the laser chip is electrically connected with the negative conducting plate through a routing, and the positive pin of the laser chip is electrically connected with the positive conducting plate through a routing;

the heating terminal positive pin is electrically connected with the first heating terminal through a routing;

the ground hole penetrates through the front surface and the back surface of the ceramic circuit substrate and is electrically connected with the fan-shaped column;

one end of the first heating resistor and one end of the second heating resistor are electrically connected with the first heating terminal respectively, and the other end of the first heating resistor and the other end of the second heating resistor are electrically connected with the ground hole respectively.

Further, in the low-power CWDM optical module, the laser further includes a TO base, a ceramic circuit board, a ground pin, a laser chip positive pin, a laser chip negative pin, and a heating terminal positive pin;

the TO base is electrically connected with the grounding pin;

the front surface of the ceramic circuit substrate is provided with a laser chip, a negative conducting strip and a positive conducting strip;

the laser chip negative pin is electrically connected with the negative conducting plate through gold-tin eutectic welding, and the laser chip positive pin is electrically connected with the positive conducting plate through gold-tin eutectic welding;

the heating assembly comprises a first heating terminal, a second heating terminal, a third heating terminal, a fourth heating terminal, a first heating resistor and a second heating resistor, and the first heating terminal, the second heating terminal, the third heating terminal, the fourth heating terminal, the first heating resistor and the second heating resistor are arranged on the front surface of the ceramic circuit substrate;

the negative electrode conducting strip and the positive electrode conducting strip are positioned on two opposite sides of the laser chip, and the first heating resistor and the second heating resistor are positioned on the other two sides of the laser chip;

the first heating terminal and the second heating terminal are positioned at two ends of the first resistor, and the third heating terminal and the fourth heating terminal are positioned at two ends of the second resistor;

the first heating terminal and the third heating terminal are electrically connected through an internal gold wire, and are electrically connected with a positive pin of the heating terminal through a routing wire;

the second heating terminal and the fourth heating terminal are electrically connected through an internal gold wire, and are electrically connected with the TO base through a routing wire.

Further, in the low-power CWDM optical module, the first heating resistor, the second heating resistor, and the first heating terminal are all obtained by etching metal on the front surface of the ceramic circuit substrate.

Further, in the low power CWDM optical module, the first heating resistor, the second heating resistor, the first heating terminal, the second heating terminal, the third heating terminal, and the fourth heating terminal are all obtained by etching metal on the front surface of the ceramic circuit substrate.

Further, in the low-power-consumption CWDM optical module, the distance between the first heating resistor and the laser chip is 0.15mm-0.4 mm;

the distance between the second heating resistor and the laser chip is 0.15mm-0.4 mm.

Further, in the low-power-consumption CWDM optical module, the laser driver and the laser are connected by a dc coupling circuit;

the direct current coupling circuit comprises a third capacitor, a filtering unit, a first anti-surge unit, a third inductor, a second anti-surge circuit and a fourth inductor;

one end of the third capacitor is connected with a VCCTP pin of the laser driver, and the other end of the third capacitor is connected with the VCCTN pin of the laser driver;

the VCCTN pin of the laser driver is connected with the SVCC pin of the laser driver;

one end of the filter unit is connected with a VCCTO pin of the laser driver, and the other end of the filter unit is grounded;

the TXOUTP pin of the laser driver is connected with an LD-pin of a laser chip in the laser, and the TXOUTN pin of the laser driver is connected with an LD + pin of the laser chip;

one end of the first anti-surge unit is connected with a BIAS _ OUT pin of the laser driver, and the other end of the first anti-surge unit is connected with one end of the third inductor; the other end of the third inductor is connected between a TXOUTP pin of the laser driver and an LD-pin of the laser chip;

one end of the second anti-surge circuit is connected with a VCCTN pin of the laser driver, and the other end of the second anti-surge circuit is connected with one end of the fourth inductor; the other end of the fourth inductor is connected between a TXOUTN pin of the laser driver and an LD + pin of the laser chip;

the GND1 pin, the GND2 pin, the GND3 pin and the GND4 pin of the laser chip are all grounded, the PD-pin of the laser chip is connected with the IPIN pin of the laser driver, and the HEAT pin of the laser chip is connected with the heating component.

Further, in the low-power CWDM optical module, the filter unit includes a fourth capacitor and a fifth capacitor;

the fourth capacitor and the fifth capacitor are connected in parallel.

Further, in the low-power CWDM optical module, the first anti-surge unit includes a second inductor and a third resistor;

the second inductor and the third resistor are connected in parallel.

Further, in the low-power CWDM optical module, the second anti-surge unit includes a fifth inductor and a fourth resistor;

the fifth inductor is connected in parallel with the fourth resistor.

Compared with the prior art, the embodiment of the utility model provides a following beneficial effect has:

the embodiment of the utility model provides a pair of low-power consumption CWDM optical module, through changing heating circuit, and let the control unit output PWM signal give heating element, make heating circuit can export corresponding heating voltage after receiving the PWM signal and give heating element, realize the heating to heating element, not only promoted heating circuit's conversion efficiency, with the heating efficiency who promotes heating circuit, and reduced the heating consumption, thereby saved the heating cost, the meaning of very being worth adopting and promoting has.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a low power consumption CWDM optical module according to an embodiment of the present invention;

fig. 2 is a schematic circuit schematic structure diagram of a heating circuit provided by an embodiment of the present invention;

fig. 3 is an output voltage simulation diagram of different duty ratios in an embodiment of the present invention;

fig. 4 is a schematic diagram of a ceramic circuit substrate according to an embodiment of the present invention in a distributed full-wrapping design;

fig. 5 is a schematic diagram of a ceramic circuit substrate according to an embodiment of the present invention in a distributed two-sided package design;

fig. 6 is a diagram illustrating a simulation result of heating power of a ceramic circuit substrate having an overall resistance of 30 Ω according to an embodiment of the present invention;

fig. 7 is a diagram illustrating a simulation result of heating power of a ceramic circuit substrate having an overall resistance of 10 Ω according to an embodiment of the present invention;

fig. 8 is a schematic circuit schematic structure diagram of a dc coupling circuit according to an embodiment of the present invention.

Reference numerals:

an electrical interface unit 1, a light receiving unit 2, a control unit 3, a heating circuit 4 and a light emitting unit 5;

a limiting amplifier 21, a photodetector 22;

a laser driver 51 and a laser 52.

Detailed Description

In order to make the objects, features and advantages of the present invention more obvious and understandable, the embodiments of the present invention are clearly and completely described with reference to the drawings in the embodiments of the present invention, and obviously, the embodiments described below are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

In the description of the present invention, it is to be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present.

Furthermore, the terms "long", "short", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships illustrated in the drawings, and are only for convenience of describing the present invention, but do not indicate or imply that the device or element referred to must have the specific orientation, operate in the specific orientation configuration, and thus, should not be construed as limiting the present invention.

The technical solution of the present invention is further explained by the following embodiments with reference to the accompanying drawings.

In view of the above-mentioned drawbacks of the conventional heating technology for CWDM optical modules, the applicant of the present invention is based on practical experience and professional knowledge that is abundant over many years in the design and manufacture of such products, and is applied with the theory to actively make research and innovation, so as to hopefully create a technology capable of solving the drawbacks of the conventional technology, so that the heating technology for CWDM optical modules has higher practicability. Through continuous research and design, and after repeated trial sample and improvement, the utility model discloses the practical value of utensil is established in the end.

Referring to fig. 1-8, an embodiment of the present invention provides a low power consumption CWDM optical module, as shown in fig. 1, including an electrical interface unit 1, a light receiving unit 2, a control unit 3, a heating circuit 4, and a light emitting unit 5; wherein the content of the first and second substances,

the light receiving unit 2 includes a limiting amplifier 21 and a photodetector 22;

the light emitting unit 5 includes a laser driver 51 and a laser 52, the laser 52 including a heating component;

the electrical interface unit 1 is electrically connected with the limiting amplifier 21, the control unit 3 and the laser driver 51 respectively;

the limiting amplifier 21 is electrically connected with the optical detector 22;

the laser driver 51 is electrically connected with the laser 52;

the control unit 3 is electrically connected with the heating circuit 4 and is used for outputting a PWM signal to the heating circuit 4;

the heating circuit 4 is electrically connected with the heating component and is used for outputting corresponding heating voltage to the heating component after receiving the PWM signal so as to heat the heating component.

It should be noted that, an object of this embodiment is to reduce heating power consumption of the industrial CWDM optical module, especially at a low temperature, so that the heating power consumption of the industrial CWDM optical module is as low as possible, thereby achieving energy saving and environmental protection, and controlling heating cost as much as possible.

In order to overcome the problem that the heating power consumption of the current industrial CWDM optical module is high at low temperature, the present embodiment provides three different heating modes for reducing the heating power consumption, which are a heating mode using a change heating circuit and PWM control, a heating mode redesigning a heating resistor layout, and a heating mode reducing the bias current of a laser chip through dc coupling, and specifically includes the following steps:

in the first heating mode, that is, a heating circuit is changed and PWM control is used, in this embodiment, as shown in fig. 2, the heating circuit includes a PMOS transistor Q1, a freewheeling diode D1, a magnetic bead FB, a first resistor R1, a second resistor R2, a first inductor L1, a first capacitor C1, and a second capacitor C2;

in fig. 2, the heating assembly is denoted Heater;

the gate of the PMOS transistor Q1 is electrically connected to one end of the first resistor R1, the source of the PMOS transistor Q1 is electrically connected to one end of the second resistor R2, and the drain of the PMOS transistor Q1 is electrically connected to one end of the first inductor L1;

the other end of the first resistor R1 is electrically connected with the control unit 3;

the other end of the second resistor R2 is electrically connected between the gate of the PMOS transistor Q1 and the first resistor R1;

the other end of the first inductor L1 is electrically connected with the heating element;

one end of the second capacitor C2 is electrically connected between the source of the PMOS transistor Q1 and the second resistor R2, and the other end of the second capacitor C2 is grounded;

the anode of the freewheeling diode D1 is electrically connected between the second capacitor C2 and the ground, and the cathode of the freewheeling diode D1 is electrically connected between the drain of the PMOS transistor Q1 and the first inductor L1;

one end of the magnetic bead FB is electrically connected between the source of the PMOS tube Q1 and the second resistor R2;

one end of the first capacitor C1 is electrically connected between the first inductor L1 and the heating element, and the other end of the first capacitor C1 is grounded.

It should be noted that, by using a low-value heating element and using the Buck-type heating circuit 4 instead of the analog adjustment method in the prior art to achieve the purpose of transferring energy to the heating element, the transfer efficiency of energy can be improved from 45% to 69%, and this heating method can reduce 0.15W at low temperature, and is a high-efficiency heating method. In fig. 2, a PMOS transistor Q1 is used as a switching element, a freewheeling diode D1 is added, and an inductive device is added between the switching element and the heating element. As can be seen from the output voltage simulation diagram shown in fig. 3, the PWM (operating at 100KHz) has different duty cycle outputs (10%, 30%, 60%, 90%), and different output voltages, which are respectively 0.74V, 1.51V, 2.29V, and 3.19V; a comparison was made according to a typical 10 omega heating resistor with a prior art simulation adjustment and the performance comparison table is shown in table 1 below. In addition, the analog adjustment in the prior art needs to use 1-path DAC, and the MCU has the requirement of analog function; and the PWM heating mode almost meets all digital MCUs, and a precious DAC port or resource can be saved.

Table 1: heating mode adjustment and simulation adjustment comparison table by PWM-Buck

It can be seen from the comparison table that the heating power of 0.5W or below is obviously superior to the analog adjustment mode by using the PWM adjustment heating mode, and the power consumption can save the average value of 133 mW; during large heating power, the power consumption of PWM adjustment is equivalent to that of analog adjustment, and during 1W heating power consumption, the whole power of the PWM is slightly larger than that of the analog adjustment by about 4mW due to switching loss. This simulation and calculation is very close to the actual test, in which case, of course, the MCU can be easily switched to straight-through heating to reduce switching losses.

The second heating mode, i.e. the heating mode for redesigning the heating resistor layout, is an optimization method based on thermal analysis. Specifically, by reducing the thermal resistance between the paths from the heating resistor to the LD (Laser Diode, Laser chip), the heating power required at low temperature can be reduced, and there are two implementation manners: one of them is to control the path thermal resistance from the heating resistor to the LD; the other is to add a heating resistance directly on the LD.

The analytical procedure was as follows: the thermal resistance from the active area of the LD TO the TO external is approximately 130k/W, and the results made by different manufacturers are different due TO different welding of the LD. The heating resistance is to add a heat source to the heat path between the LD active region and the outside. The heating effect depends on the ratio of the heating resistance to the thermal resistance of the LD and to the external thermal resistance. For the current common industrial CWDM optical module, the heating resistance spends 0.63W on average and pulls back 11.4 degrees on average through calculation. The power consumption pull-back wavelength coefficient is about 0.055W/C, and the thermal resistance value from the heating resistor to the outside is 18.09K/W; from this value, it can be estimated that the current heating resistor is rather outside in the position of the thermal path, i.e. a large part (the more 86%) of the heat is dissipated to the outside; referring to the patent publication No. CN215732669U (a laser with a heating resistor), from the viewpoint of providing a laser structure, the heating resistor and the LD are not in direct contact, and there is no good thermal connection to reduce the thermal resistance. On the other hand, the LD and the heating resistor do not form a surrounding relationship, which may cause heat leakage from the LD itself to the heating resistor, and thus the heating effect of the heating resistor is not good.

It is important TO recognize that the heating efficiency of the heat is very important because the heating resistance contributes only 13% TO the temperature rise of the LD, which is also the case where the heating resistance is inside the TO, and the case where the heating resistance is on a flexible board, where the heat is in the outside, and the heating effect on the LD may be worse.

This embodiment has designed two kinds of optimization schemes through thermal analysis, all is through carrying out the territory improvement to ceramic circuit substrate to improve the territory that is located the heating resistance above that, promote ceramic circuit substrate's heating effect.

In the CN215732669U patent (a laser with heating resistor), the original electrical connection between the lead 12 (laser diode negative lead) and the lead 13 (laser diode positive lead) is made by soldering gold and tin on a ceramic circuit substrate, which can increase the heat dissipation effect, but at the same time, leads to an undesirable path for heat to pass.

The heating element in this embodiment is directly obtained by etching the metal on the front surface of the ceramic circuit substrate, and the LD is surrounded (entirely surrounded or surrounded on both sides), so that leakage of heat from the LD during heating can be prevented.

In one embodiment, the laser 52 further comprises a TO base, a ceramic circuit substrate, a fan-shaped post, a ground pin, a laser chip positive pin, a laser chip negative pin, and a heater terminal positive pin;

the TO base is electrically connected with the grounding pin;

the heating assembly comprises a first heating terminal (namely a Heater in figures 2 and 8), a first heating resistor and a second heating resistor, wherein the first heating terminal, the first heating resistor and the second heating resistor are arranged on the front surface of the ceramic circuit substrate, and the front surface of the ceramic circuit substrate is also provided with a laser chip (LD), a negative electrode conducting sheet (LD-), a positive electrode conducting sheet (LD +) and a ground hole;

In this embodiment, the laser chip is fully wrapped, the first heating terminal corresponds to a positive electrode, the ground hole corresponds to a negative electrode, and the first heating resistor and the second heating resistor are connected in parallel.

The first heating resistor, the second heating resistor and the first heating terminal may be directly etched from a metal on the front surface of the ceramic circuit substrate.

In another embodiment, the laser 52 further comprises a TO base, a ceramic circuit substrate, a ground pin, a laser chip positive pin, a laser chip negative pin, and a heater terminal positive pin;

the TO base is electrically connected with the grounding pin;

the front surface of the ceramic circuit substrate is provided with a laser chip (LD), a negative electrode conducting plate (LD-) and a positive electrode conducting plate (LD +);

the heating assembly comprises a first heating terminal, a second heating terminal, a third heating terminal, a fourth heating terminal (four heating terminals, namely Heater in figures 2 and 8), a first heating resistor and a second heating resistor, wherein the first heating terminal, the second heating terminal, the third heating terminal, the fourth heating terminal, the first heating resistor and the second heating resistor are arranged on the front surface of the ceramic circuit substrate;

In this embodiment, the laser chip is wrapped in two sides, the first heating terminal and the third heating terminal correspond to positive electrodes, the second heating terminal and the fourth heating terminal correspond to negative electrodes, positive and negative electrodes of the first heating resistor and the second heating resistor are respectively connected to the positive electrodes and the negative electrodes, and the first heating resistor and the second heating resistor are connected in parallel.

The first heating resistor, the second heating resistor, the first heating terminal, the second heating terminal, the third heating terminal and the fourth heating terminal may all be obtained by directly etching metal on the front surface of the ceramic circuit substrate.

Because the second heating terminal with the fourth heating terminal through the routing with TO base electric connection TO realize ground connection, consequently this kind of mode can avoid beating on ceramic circuit substrate the ground hole has promoted the roughness of gold tin bonding surface.

It should be noted that, the first one in the above embodiments is a wire bonding manner, so that the heating resistor can fully wrap the LD, that is, the heated LD is mainly located in the heating region, thereby reducing leakage of the heat path of the LD itself, raising the position of the heating resistor from the thermal resistance position of 18K/W to a more ideal value, raising the value of the equivalent heating thermal resistance of the LD, where the resistance of the first heating resistor and the second heating resistor after layout change is 6R, and after parallel connection is 3R, assuming that 10 Ω/square, and the overall resistance is 30 Ω. The second one is two-side wrapping, the resistance of the first heating resistor and the second heating resistor on two sides is approximately 2R, and 1R is formed after parallel connection; the electrical performance of the heating resistor in this embodiment is similar to that of the previous embodiment, but the heating effect of the heating resistor is also greatly improved due to the formation of distributed heating.

In this embodiment, the distance from the heating resistor to the LD portion is performed according to a distance range (6mil to 16mil, about 0.15mm to 0.4mm), so that the thermal resistance from the heating resistor to the LD portion is as small as possible while meeting the process requirements. In addition, the heating terminal is an electrical interface of the first heating resistor or the second heating resistor, and the surface layer has a gold plating layer and can be used for bonding a gold wire for electrical connection. The heating terminal is directly electrically connected with the heating resistor.

Through estimation, the equivalent heating thermal resistance of the two embodiments to the LD can be improved to about 36-50K/W, and then at a low temperature (such as-40 ℃), the LD is pulled back by 14 degrees, and the LD can be heated only by 0.35W of heating power consumption in the calculation of 40K/W equivalent heating thermal resistance, so that the LD can save 0.35W of power consumption relative to 0.7W. The circuit is also very suitable, large heating power consumption can not occur, and the power consumption of the module can be prevented from exceeding the standard. The simulation results for different duties of 10 Ω and 30 Ω are shown in fig. 6 and 7.

In the embodiment, after layout surrounding and optimization, the heat leakage of the LD is reduced during heating, and the equivalent thermal resistance value of the heating resistor to the LD is increased; the power temperature rise coefficient (K/W) of the heating resistor is greatly improved compared with the original power temperature rise coefficient, the required heating power consumption is greatly reduced, the heating resistor is realized by basic graphs, the power resistor is not required to be pasted, and the pasting process can be saved.

A third heating method, that is, a heating method for reducing the bias current of the laser chip by dc coupling, changes the coupling method between the laser driver 51 and the laser 52, that is, in this embodiment, as shown in fig. 8, the laser driver 51 and the laser 52 are electrically connected by a dc coupling circuit;

the direct current coupling circuit comprises a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a second inductor L2, a third inductor L3, a fourth inductor L4, a fifth inductor L5, a third resistor R3 and a fourth resistor R4;

one end of the third capacitor C3 is electrically connected to the VCCTP pin of the laser driver 51, and the other end of the third capacitor C3 is electrically connected to the VCCTN pin of the laser driver 51;

the VCCTN pin of the laser driver 51 is electrically connected with the SVCC pin of the laser driver 51;

the fourth capacitor C4 and the fifth capacitor C5 are connected in parallel to form a filter unit, one end of the filter unit is electrically connected with the VCCTO pin of the laser driver 51, and the other end of the filter unit is grounded;

the TXOUTP pin of the laser driver 51 is electrically connected with the LD-pin of the laser diode in the laser 52, and the TXOUTN pin of the laser driver 51 is electrically connected with the LD + pin of the laser diode;

after the second inductor L2 and the third resistor R3 are connected in parallel to form a first anti-surge unit, one end of the first anti-surge unit is electrically connected to the BIAS _ OUT pin of the laser driver 51, and the other end of the first anti-surge unit is electrically connected to one end of the third inductor L3; the other end of the third inductor L3 is electrically connected between the TXOUTP pin of the laser driver 51 and the LD-pin of the laser diode;

after the fifth inductor L5 and the fourth resistor R4 are connected in parallel to form a second anti-surge unit, one end of the second anti-surge unit is electrically connected to the VCCTN pin of the laser driver 51, and the other end of the second anti-surge unit is electrically connected to one end of the fourth inductor L4; the other end of the fourth inductor L4 is electrically connected between the TXOUTN pin of the laser driver 51 and the LD + pin of the laser diode;

the pin GND1, the pin GND2, the pin GND3 and the pin GND4 of the laser diode are all grounded, the PD-pin of the laser diode is electrically connected with the pin IPIN of the laser driver 51, and the HEAT pin of the laser diode is electrically connected with the heating element (specifically, with a heating terminal, indicated as Heater in fig. 8).

It should be noted that, by using dc coupling instead of ac coupling in the prior art, the current of the transmitting functional circuit itself can be reduced. A high speed signal direct connection is made between the laser driver 51 and the laser 52, with a bias current from VCCTN to LD +, across LD, to LD-, from Ibias node to a controlled current source inside the laser driver 51; the two-stage Bias-T can achieve good high-frequency isolation, the voltages of the output ends of the laser chip, namely an LD + pin and an LD-pin, are asymmetric and unequal, and the difference value of the voltages is determined by the voltage of a load LD; it can be calculated that: when the current of P1& P0 corresponds to I1& I0; when AC coupling is carried out, the bias current Ib is 0.5(I1 + I0), and the modulation current Im is I1-I0; when the direct current is coupled, the bias current is I0; the modulation current Im is unchanged and is still I1-I0; thus, through direct current coupling, the bias current Ib is from 0.5(I1 + I0) to I0, and 0.5(I1-I0) is reduced, namely 0.5 times of modulation current, so that the aim of saving power consumption is achieved. For example, when the modulation current is 50mA, the ac coupling is changed into the dc coupling, the saved current is 25mA, and the power consumption saving is about 82mW, which can be achieved by a suitable LDD device, and will not be described herein.

The three heating modes of the embodiment can be realized on the product independently or in combination. The circuit optimization is provided through a first heating mode, the energy transfer efficiency can be improved from 45% to 69%, and the energy transfer efficiency can be reduced by 0.15W under the low-temperature condition; the second heating mode provides heating equivalent thermal resistance and distributed wrapping heating, changes the original lumped heating resistance, can greatly improve the heating equivalent thermal resistance, can reduce the originally required heating power from 0.7W to 0.35W, and indicates that the heating part is directly placed in the LD, which is a future development direction; and in the third heating mode, the alternating current coupling is changed into the direct current coupling, so that the method is mainly suitable for optimizing the original alternating current coupled optical module, and the power consumption can be reduced by about 25mA and about 0.08W.

Although the terms electrical interface unit, light receiving unit, control unit, heating circuit, light emitting unit, etc. are used more often herein, the possibility of using other terms is not excluded. These terms are used merely to more conveniently describe and explain the nature of the present invention; they are to be construed in a manner that is inconsistent with the spirit of the invention.

The embodiment of the utility model provides a pair of low-power consumption CWDM optical module, through changing heating circuit, and let the control unit output PWM signal give heating element, make heating circuit can export corresponding heating voltage after receiving the PWM signal and give heating element, realize the heating to heating element, not only promoted heating circuit's conversion efficiency, in order to promote heating circuit's heating efficiency, and reduced the heating consumption moreover, thereby saved the heating cost, have the meaning of very being worth adopting and promoting.

The foregoing description of the embodiments has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same elements or features may also vary in many respects. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Example embodiments are provided so that this disclosure will be thorough and will fully convey the scope to those skilled in the art. Numerous details are set forth, such as examples of specific parts, devices, and methods, in order to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In certain example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises" and "comprising" are intended to be inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed and illustrated, unless explicitly indicated as an order of performance. It should also be understood that additional or alternative steps may be employed.

When an element or layer is referred to as being "on" … … "," engaged with "… …", "connected to" or "coupled to" another element or layer, it can be directly on, engaged with, connected to or coupled to the other element or layer, or intervening elements or layers may also be present. In contrast, when an element or layer is referred to as being "directly on … …," "directly engaged with … …," "directly connected to" or "directly coupled to" another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship of elements should be interpreted in a similar manner (e.g., "between … …" and "directly between … …", "adjacent" and "directly adjacent", etc.). As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region or section from another element, component, region or section. Unless clearly indicated by the context, use of terms such as the terms "first," "second," and other numerical values herein does not imply a sequence or order. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

Spatially relative terms, such as "inner," "outer," "below," "… …," "lower," "above," "upper," and the like, may be used herein for ease of description to describe a relationship between one element or feature and one or more other elements or features as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the example term "below … …" can encompass both an orientation of facing upward and downward. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted.

Claims

1. A low-power consumption CWDM optical module is characterized by comprising a control unit, a heating circuit, a laser driver and a laser; wherein the content of the first and second substances,

the laser driver is connected with the laser;

the laser comprises a heating component;

the other end of the first resistor is connected with the control unit;

the other end of the first inductor is connected with the heating assembly;

2. The low power consumption CWDM optical module of claim 1, wherein the laser further comprises a TO base, a ceramic circuit substrate, a sector post, a ground pin, a laser chip positive pin, a laser chip negative pin, and a heating terminal positive pin;

the TO base is electrically connected with the grounding pin;

3. The low-power CWDM optical module of claim 1, wherein the laser further comprises a TO base, a ceramic circuit substrate, a ground pin, a laser chip positive pin, a laser chip negative pin, and a heating terminal positive pin;

the TO base is electrically connected with the grounding pin;

4. The low-power CWDM optical module of claim 2, wherein the first heating resistor, the second heating resistor, and the first heating terminal are all etched from a metal on the front surface of the ceramic circuit substrate.

5. The low-power-consumption CWDM optical module of claim 3, wherein the first heating resistor, the second heating resistor, the first heating terminal, the second heating terminal, the third heating terminal and the fourth heating terminal are all etched from metal on the front surface of the ceramic circuit substrate.

6. The low-power-consumption CWDM optical module of claim 2 or 3, wherein the distance between the first heating resistor and the laser chip is 0.15-0.4 mm;

7. The low-power CWDM optical module of claim 1, wherein the laser driver and the laser are connected by a dc coupling circuit;

a TXOUTP pin of the laser driver is connected with an LD-pin of a laser chip in the laser, and a TXOUTN pin of the laser driver is connected with an LD + pin of the laser chip;

8. The low-power consumption CWDM optical module of claim 7, wherein said filtering unit comprises a fourth capacitor and a fifth capacitor;

the fourth capacitor and the fifth capacitor are connected in parallel.

9. The low-power consumption CWDM optical module of claim 7, wherein said first anti-surge unit comprises a second inductor and a third resistor;

the second inductor and the third resistor are connected in parallel.

10. The low-power consumption CWDM optical module of claim 7, wherein the second anti-surge unit comprises a fifth inductor and a fourth resistor;

the fifth inductor is connected in parallel with the fourth resistor.