Current monitoring circuit, optical module circuit and optical module
By connecting ceramic thick film resistors in parallel at both ends of the sampling resistor of the current monitoring circuit, the problem of reduced accuracy of optical module current monitoring when temperature changes is solved, achieving higher monitoring accuracy and lower power consumption.
Patent Information
- Application Number
- CN202421075926.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-17
- Publication Date
- 2025-04-18
- Estimated Expiration
- 2034-05-17
AI Technical Summary
Existing current monitoring circuits cannot accurately monitor the current and power consumption of optical modules, especially when temperature changes, resulting in inaccurate monitoring.
A ceramic thick film resistor is connected in parallel at both ends of the sampling resistor. Taking advantage of the small temperature drift coefficient and large resistance value of the ceramic thick film resistor, the total resistance after parallel is reduced, so that it has a small impact on temperature changes.
It effectively avoids the problem of reducing current detection accuracy caused by temperature changes in the sampling resistor value, and at the same time reduces the voltage drop across the sampling resistor, reducing the additional power consumption introduced by current sampling.
Smart Images
Figure CN222774616U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of optical communication technology, and in particular to a current monitoring circuit, an optical module circuit and an optical module. Background Art
[0002] With the development of new services and application models such as cloud computing, mobile Internet, and video, the development and progress of optical communication technology has become increasingly important. In optical communication technology, optical modules are tools for realizing the mutual conversion of optical and electrical signals, and are one of the key components in optical communication equipment. In addition, with the development of optical communication technology, the transmission rate of optical modules is constantly increasing.
[0003] With the construction of data centers of major enterprises, optical modules, as the core components of data centers, have played a core role. In a data center, tens of thousands of optical modules are often needed, and the real-time power consumption monitoring of these optical modules is particularly important. At present, the power consumption detection of optical modules usually uses a current amplifier chip to connect a sampling resistor for current sampling to detect the working current and power consumption of the optical module in real time. In order to reduce the voltage drop across the sampling resistor and reduce the additional power consumption introduced by current sampling, a copper foil of a circuit board can be connected in the circuit as a sampling resistor. Due to the flexible design of the copper foil of the circuit board, the resistance value can be very small, thereby minimizing the additional power consumption introduced by current sampling.
[0004] However, the resistance of the copper foil of the circuit board is greatly affected by temperature. As the ambient temperature changes, the resistance of the copper foil changes accordingly, which will affect the accuracy of real-time power consumption monitoring and lead to inaccurate monitoring and other problems. Utility Model Content
[0005] The present application provides a current monitoring circuit, an optical module circuit and an optical module to solve the technical problem that the existing current monitoring circuit cannot accurately perform current detection on the circuit to be monitored.
[0006] In a first aspect, a current monitoring circuit is provided, the current monitoring circuit comprising a sampling resistor and a ceramic thick film resistor connected in parallel therewith, the sampling resistor being coupled in series in a circuit to be monitored; the sampling resistor being constructed of at least one conductive trace in a circuit board; the resistance of the ceramic thick film resistor being greater than or equal to 1 ohm, and the two ends of the ceramic thick film resistor being electrically connected to the conductive trace via a first conductive pad and a second conductive pad on a surface of the circuit board.
[0007] In some embodiments, in the thickness direction of the circuit board, a projection of the ceramic thick film resistor overlaps with a projection of at least one conductive trace in the sampling resistor.
[0008] In some embodiments, the sampling resistor is located on a surface layer of a circuit board, and the first conductive pad and the second conductive pad are electrically connected to the sampling resistor.
[0009] In some embodiments, the sampling resistor is located in an inner layer of a circuit board, and the first conductive pad and the second conductive pad are electrically connected to the sampling resistor through first conductive vias, respectively.
[0010] In some embodiments, the conductive trace is made of Cu.
[0011] In some embodiments, the impedance of the sampling resistor is in milliohm range.
[0012] In some embodiments, the sampling resistor is constructed by a plurality of conductive traces in a circuit board, the plurality of conductive traces are arranged at intervals in a thickness direction of the circuit board, and the plurality of conductive traces are connected in parallel.
[0013] In some embodiments, the current monitoring circuit also includes a signal amplification circuit, which includes a first function pin, a second function pin and an output pin; wherein the first function pin is electrically connected to the first conductive pad, the second function pin is electrically connected to the second conductive pad, and the output pin is used to output the sampled and amplified current signal.
[0014] According to the second aspect of the present application, an optical module circuit is provided, which includes a power-on slow start circuit and any of the current monitoring circuits described above; the input end of the power-on slow start circuit is coupled to the power pin of the optical module circuit, and the sampling resistor of the current monitoring circuit is coupled to the output end of the power-on slow start circuit to collect and monitor the output current of the slow start circuit.
[0015] According to a third aspect, an optical module is provided, wherein the optical module comprises the optical module circuit according to the second aspect.
[0016] The present application can achieve the following beneficial effects: A current monitoring circuit proposed in the present application is designed to connect a ceramic thick film resistor in parallel at both ends of a sampling resistor, and utilize the fact that the temperature drift coefficient of the ceramic thick film resistor is relatively small, and the ceramic thick film resistor has a larger resistance value than the sampling resistor. The total resistance after parallel connection is reduced, so that even if the resistance value of the sampling resistor is affected by temperature changes, the total resistance after parallel connection is slightly affected, thereby avoiding the problem of reduced accuracy of current detection caused by the resistance value of the original sampling resistor being affected by temperature changes. In addition, since the resistance value of the total resistance after parallel connection is reduced, the voltage drop across the sampling resistor is further reduced, thereby reducing the additional power consumption introduced by current sampling. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.
[0018] Figure 1 A schematic diagram of the structure of a current monitoring circuit provided in an embodiment of the present application;
[0019] Figure 2 A schematic diagram of the structure of a circuit board stack provided in one embodiment of the present application;
[0020] Figure 3 A schematic structural diagram of a circuit board stack provided in yet another embodiment of the present application;
[0021] Figure 4 A schematic diagram of the structure of a circuit board stack provided in another embodiment of the present application;
[0022] Figure 5 A schematic diagram of the structure of another current monitoring circuit provided in an embodiment of the present application;
[0023] Figure 6 A schematic diagram of the structure of an optical module circuit provided in an embodiment of the present application.
[0024] Reference numerals:
[0025] 100-circuit board; 300-ceramic thick film resistor; 10-conductive trace; 110-first conductive pad; 120-second conductive pad; 20-conductive layer; 30-insulating layer; 40-first conductive via; 50-second conductive via; 60-third conductive via; 700-signal amplifying circuit; 701-first functional pin; 702-second functional pin; 800-power-on slow start circuit; 801-input end of the power-on slow start circuit; 802-output end of the power-on slow start circuit. DETAILED DESCRIPTION
[0026] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.
[0027] It should be understood that in the following description, "circuit" refers to a conductive loop composed of at least one element or subcircuit through electrical connection or electromagnetic connection. When an element or circuit is said to be "connected to" another element, an element or circuit is "connected" to another element, or an element / circuit is "connected" between two nodes, it can be directly coupled or connected to another element or there can be an intermediate element. The connection between the elements can be physical, logical, or a combination thereof. Conversely, when an element is said to be "directly coupled to" or "directly connected to" another element, it means that there is no intermediate element between the two.
[0028] The terms "comprises," "comprising," or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.
[0029] As the capacity of optical modules increases, the power consumption increases, and the current of optical modules becomes very high. Optical modules often fail at the customer switch application end. Therefore, the detection of the current consumption of optical modules becomes more and more important. To this end, the present application provides a current monitoring circuit to detect the working current and power consumption of optical modules in real time.
[0030] Figure 1 A schematic diagram of the structure of a current monitoring circuit provided in an embodiment of the present application. Figure 2 A schematic diagram of the structure of a circuit board stack provided in one embodiment of the present application.
[0031] For example, please refer to Figure 1 The current monitoring circuit includes a sampling resistor and a ceramic thick film resistor 300 connected in parallel therewith. The sampling resistor is coupled in series in the circuit to be monitored. The node N1 in the figure serves as the first end of the current monitoring circuit, and the node N2 serves as the second end of the current monitoring circuit. The resistance of the ceramic thick film resistor 300 is greater than or equal to 1 ohm, and the impedance of the sampling resistor is in the milliohm level.
[0032] For example, Figure 2As shown, the sampling resistor can be realized by a conductive trace composed of copper foil directly printed on a printed circuit board (PCB). Wherein, the PCB board is a support for electronic components and a carrier for electrical interconnection of electronic components. The circuit board includes a plurality of metal layers 20 spaced apart in the thickness direction, a substrate layer 30 spaced between two adjacent metal layers 20, and a solder mask layer (not shown) located on the surface of the circuit board. Specifically, the sampling resistor is constructed by at least one conductive trace in the circuit board 100. Wherein, the length and thickness of the conductive trace can be made according to the resistance value of the sampling resistor in the actual current monitoring circuit. The conductive trace is flexible in design and can realize the use of a resistor with a smaller resistance value, thereby reducing the additional power consumption introduced by the sampling circuit. However, the resistance value of the copper foil of the circuit board is greatly affected by temperature. As the ambient temperature changes, the resistance value of the copper foil changes accordingly, which will affect the accuracy of real-time power consumption monitoring and lead to problems such as inaccurate monitoring. Therefore, the present application connects a ceramic thick film resistor in parallel to the sampling resistor composed of the conductive trace to reduce the influence of the resistance change of the sampling resistor on the sampling signal and improve the accuracy of sampling. For example, in this embodiment, two ends of the ceramic thick film resistor 300 are electrically connected to the conductive trace 10 via a first conductive pad 110 and a second conductive pad 120 on the surface of the circuit board.
[0033] Continue to refer to Figure 2 As shown, in this embodiment, the sampling resistor is constructed by a conductive trace 10 located on the surface of the circuit board 100. Generally, in order to minimize the additional power consumption introduced by current sampling, the resistance of the conductive trace 10 constructed by copper foil can be within the range of 30 to 50 mohm. In order to facilitate the subsequent mounting of the ceramic thick film resistor 300, the first conductive pad 110 and the second conductive pad 120 are constructed by using the copper foil on the surface of the circuit board 100. At this time, the first conductive pad 110 and the second conductive pad 120 can be directly formed at both ends of the conductive trace 10. The two ends of the ceramic thick film resistor 300 can be welded on the top of the sampling resistor by welding, so as to realize parallel electrical connection with the conductive trace 10 through the first conductive pad 110 and the second conductive pad 120 on the surface of the circuit board 100.
[0034] In an embodiment of the present application, the current monitoring circuit includes a sampling resistor and a ceramic thick film resistor connected in parallel therewith, wherein the sampling resistor is coupled in series in the circuit to be monitored, and is intended to connect a ceramic thick film resistor in parallel at both ends of the sampling resistor, and utilize the fact that the temperature drift coefficient of the ceramic thick film resistor is relatively small, and the ceramic thick film resistor has a larger resistance than the sampling resistor, so that the total resistance after parallel connection is reduced, so that even if the resistance of the sampling resistor is affected by temperature changes, the total resistance after parallel connection is slightly affected, thereby avoiding the problem of reduced accuracy of current detection caused by the original resistance of the sampling resistor being affected by temperature changes. In addition, since the resistance of the total resistance after parallel connection is reduced, the voltage drop across the sampling resistor is further reduced, thereby reducing the additional power consumption introduced by current sampling.
[0035] In some embodiments, the ceramic thick film resistor 300 is mounted on the surface of the circuit board 100 by surface mounting, so that both ends of the ceramic thick film resistor 300 are connected in parallel with the conductive trace 10 through the first conductive pad 110 and the second conductive pad 120. Further, in order to reduce the difficulty of mounting the ceramic thick film resistor 300, in this embodiment, in the thickness direction of the circuit board 100, the projection of the ceramic thick film resistor 300 overlaps with the projection of at least one conductive trace 10 in the sampling resistor.
[0036] In some embodiments, the plurality of metal layers 20 on the circuit board 100 can be electrically connected to each other through the third conductive vias 60 .
[0037] Figure 3 A schematic structural diagram of a circuit board stack provided in accordance with another embodiment of the present application.
[0038] like Figure 3 As shown, in this embodiment, the sampling resistor is located in the inner layer of the circuit board 100, that is, the sampling resistor is constructed by at least one conductive trace 10 located in the inner layer of the circuit board 100. At this time, the first conductive pad 110 and the second conductive pad 120 located on the surface of the circuit board 100 are electrically connected to the sampling resistor through the first conductive via 40. For example, the sampling resistor is constructed by the conductive trace 10 constructed by the copper sheet located on the second layer of the circuit board 100, and the first conductive pad 110 and the second conductive pad 120 located on the surface of the circuit board 100 are electrically connected to the conductive trace 10 located on the second layer of the copper sheet of the circuit board 100 through the first conductive via 40, so as to achieve parallel connection with the ceramic thick film resistor 300.
[0039] Figure 4 A schematic structural diagram of a circuit board stack provided for another embodiment of the present application.
[0040] like Figure 4As shown, in this embodiment, the sampling resistor is constructed of a plurality of conductive traces 10 in the circuit board 100, and the plurality of conductive traces 10 are arranged at intervals in the thickness direction of the circuit board 100, and the plurality of conductive traces 10 are connected in parallel to further reduce the impedance of the sampling resistor itself. Exemplarily, the plurality of conductive traces 10 are connected in parallel with each other through the second conductive vias 50.
[0041] Figure 5 A schematic diagram of the structure of another current monitoring circuit provided in an embodiment of the present application.
[0042] Continue to refer Figure 5 As shown, the current monitoring circuit also includes a signal amplifying circuit 700, and the signal amplifying circuit 700 includes a first function pin 701, a second function pin 702 and an output pin 703. Among them, the first function pin 701 is electrically connected to the first conductive pad 110 to achieve electrical connection with the node N1, and the second function pin 702 is electrically connected to the second conductive pad 120 to achieve electrical connection with the node N2, that is, the first function pin 701 and the second function pin 702 of the signal amplifying circuit 700 are respectively connected to the two ends of the sampling resistor to collect the voltage drop voltage signal at the two ends of the sampling resistor, and the signal amplifying circuit is used to process the collected voltage drop voltage signal and output the amplified current signal, and its output pin 703 is used to output the current signal. Exemplarily, the signal amplifying circuit 700 is, for example, a current amplifier chip, which amplifies the current through the current amplifier chip and outputs it to the MCU (microcontroller) or single-chip microcomputer.
[0043] Figure 6 A schematic diagram of the structure of an optical module circuit provided in an embodiment of the present application.
[0044] like Figure 6 As shown, the optical module circuit includes a power-on slow start circuit 800 and a current monitoring circuit described in any of the aforementioned embodiments, and the input end 801 of the power-on slow start circuit is coupled to the power pin of the optical module circuit, for example, electrically connected to the corresponding power pin in the gold finger arranged on the circuit board. The sampling resistor of the current monitoring circuit is coupled to the output end 802 of the power-on slow start circuit to collect and monitor the output current of the power-on slow start circuit 800, that is, to monitor the total VCCIN input current of the optical module. By monitoring the total input current, combined with the input voltage of the port, the real-time power consumption of the optical module can be monitored.
[0045] It should be understood that in the embodiment of the present application, the remaining components, the first resistor R1, the first capacitor C1, and the second capacitor C2, constitute the peripheral circuit of the optical module circuit, which will not be described in detail here.
[0046] The present application also provides an optical module, which includes the optical module circuit in the aforementioned embodiment.
[0047] Exemplarily, the optical module also includes an optical component, wherein the optical component includes a receiving end and an output end, the receiving end is used to receive an optical signal and convert the optical signal into an electrical signal for transmission to a host, and the output end is used to receive an electrical signal from the host and convert the electrical signal into an optical signal to complete the transmission of the optical signal.
[0048] The present application can achieve the following beneficial effects: The present application proposes a current monitoring circuit, an optical module circuit and an optical module, wherein the current monitoring circuit includes a sampling resistor and a ceramic thick film resistor connected in parallel therewith, wherein the sampling resistor is coupled in series in the circuit to be monitored, and is intended to connect a ceramic thick film resistor in parallel at both ends of the sampling resistor, utilizing the fact that the temperature drift coefficient of the ceramic thick film resistor is relatively small, and the ceramic thick film resistor has a larger resistance value than the sampling resistor, so that the total resistance after parallel connection is reduced, so that even if the resistance value of the sampling resistor is affected by temperature changes, the total resistance after parallel connection is affected very little, thereby avoiding the problem of reduced accuracy of current detection caused by the original resistance value of the sampling resistor being affected by temperature changes. In addition, since the resistance value of the total resistance after parallel connection is reduced, the voltage drop across the sampling resistor is further reduced, thereby reducing the additional power consumption introduced by current sampling.
[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims
1. A current monitoring circuit, characterized in that: The current monitoring circuit includes a sampling resistor and a ceramic thick film resistor connected in parallel therewith, wherein the sampling resistor is coupled in series in the circuit to be monitored; The sampling resistor is constructed as at least one conductive trace in a circuit board; The resistance of the ceramic thick film resistor is greater than or equal to 1 ohm, and both ends of the ceramic thick film resistor are electrically connected to the conductive trace through a first conductive pad and a second conductive pad on the surface of the circuit board.
2. The current monitoring circuit according to claim 1, characterized in that: In the thickness direction of the circuit board, a projection of the ceramic thick film resistor overlaps with a projection of at least one conductive trace in the sampling resistor.
3. The current monitoring circuit according to claim 1 or 2, characterized in that: The sampling resistor is located on the surface layer of the circuit board, and the first conductive pad and the second conductive pad are electrically connected to the sampling resistor.
4. The current monitoring circuit according to claim 1 or 2, characterized in that: The sampling resistor is located in the inner layer of the circuit board, and the first conductive pad and the second conductive pad are electrically connected to the sampling resistor through first conductive vias, respectively.
5. The current monitoring circuit according to claim 1, characterized in that: The conductive trace is made of Cu.
6. The current monitoring circuit according to claim 1, characterized in that: The impedance of the sampling resistor is in the milliohm level.
7. The current monitoring circuit according to claim 1, characterized in that: The sampling resistor is constructed of a plurality of conductive traces in a circuit board, the plurality of conductive traces are arranged at intervals in a thickness direction of the circuit board, and the plurality of conductive traces are connected in parallel.
8. The current monitoring circuit according to claim 1, characterized in that: The current monitoring circuit further includes a signal amplifying circuit, and the signal amplifying circuit includes a first function pin, a second function pin and an output pin; Among them, the first function pin is electrically connected to the first conductive pad, and the second function pin is electrically connected to the second conductive pad, so as to collect the voltage drop signal across the sampling resistor, the signal amplification circuit is used to process the voltage drop signal and output an amplified current signal, and the output pin is used to output the current signal.
9. An optical module circuit, characterized in that: The optical module circuit comprises a power-on slow start circuit and a current monitoring circuit according to any one of claims 1 to 8; The input end of the power-on slow start circuit is coupled to the power pin of the optical module circuit, and the sampling resistor of the current monitoring circuit is coupled to the output end of the power-on slow start circuit to collect and monitor the output current of the slow start circuit.
10. An optical module, characterized in that: The optical module comprises the optical module circuit according to claim 9.