A signal loss detection circuit and a control method of a signal loss detection circuit

Abstract

The application provides a signal loss detection circuit and a control method of the signal loss detection circuit. The circuit comprises an adjustable common-mode coupling module, a common-mode voltage generation module, a peak value detection module, a mirror peak value detection module, a comparator and a control module. The signal loss detection circuit receives a differential signal, and inputs the differential signal into the peak value detection module through the adjustable common-mode coupling module to generate a peak value signal. The common-mode voltage generation module generates a common-mode voltage and a reference common-mode voltage, outputs the common-mode voltage to the adjustable common-mode coupling module, and outputs the reference common-mode voltage to the mirror peak value detection module to generate a reference peak value signal. The comparator receives the peak value signal and the reference peak value signal and outputs a LOS signal. The control module is connected to the adjustable common-mode coupling module, the common-mode voltage generation module and an output end of the signal loss detection circuit. By using the above signal loss detection circuit and the control method of the signal loss detection circuit, the problems of large LOS delay and low signal loss detection accuracy are solved.

Description

Technical Field

[0001] This application relates to the field of communication technology, and more specifically, to a signal loss detection circuit control method and a signal loss detection circuit. Background Technology

[0002] In optical data transmission networks, when a signal is transmitted to an optical receiver via a communication channel, it is crucial to quickly and reliably determine whether a signal loss (LOS) has occurred. Optical receivers typically use a loss signal detection circuit to detect signal loss. If a signal loss is detected, the optical receiver will issue a "signal loss" alarm or status signal to notify the host system connected to the optical receiver for processing. Traditional LOS detection circuits often employ first-order or multi-order resistor-capacitor (RC) filter circuits to filter the optical signal and threshold signal before inputting them to a subsequent comparator for amplitude comparison, thereby determining whether a signal loss has occurred.

[0003] However, in traditional signal loss detection methods, the resistance and capacitance values ​​are fixed and cannot be matched for different signal frequencies, resulting in large LOS delay and low signal loss detection accuracy. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a signal loss detection circuit control method and a signal loss detection circuit to solve the problems of large LOS delay and low signal loss detection accuracy during the signal loss detection process.

[0005] In a first aspect, embodiments of this application provide a signal loss detection circuit, which includes an adjustable common-mode coupling module, a common-mode voltage generation module, a peak detection module, a mirror peak detection module, a comparator, and a control module;

[0006] The signal loss detection circuit receives the differential signal output from the previous stage circuit. After passing through the adjustable common-mode coupling module, the differential signal is input to the peak detection module to generate the peak signal.

[0007] The common-mode voltage generation module generates the common-mode voltage and the reference common-mode voltage, and outputs the common-mode voltage to the adjustable common-mode coupling module. The reference common-mode voltage is then output to the mirror peak detection module to generate the reference peak signal.

[0008] The comparator, as the output of the signal loss detection circuit, receives the peak signal and the reference peak signal, and outputs the LOS signal based on the comparison result.

[0009] The control module is connected to the input terminal of the adjustable common-mode coupling module, the input terminal of the common-mode voltage generation module, and the output terminal of the signal loss detection circuit, respectively. It detects the signal parameters of the input signal of the preceding circuit and adjusts the adjustable common-mode coupling module based on the signal parameters.

[0010] Optionally, the adjustable common-mode coupling module includes: a first variable capacitor, a first variable resistor, a second variable capacitor, and a second variable resistor; one end of the first variable capacitor receives a differential signal, the other end of the first variable capacitor is connected to one end of the first variable resistor, and the other end of the first variable capacitor also serves as the first output terminal of the adjustable common-mode coupling module and is connected to the first input terminal of the peak detection module; one end of the second variable capacitor receives a differential signal, the other end of the second variable capacitor is connected to one end of the second variable resistor, and the other end of the second variable capacitor also serves as the second output terminal of the adjustable common-mode coupling module and is connected to the second input terminal of the peak detection module; the other ends of the first variable resistor and the second variable resistor are respectively connected to the common-mode voltage generation module.

[0011] Optionally, the first variable resistor and the second variable resistor each include multiple parallel resistor paths, each resistor path including a resistor and a resistor path switch; the first variable capacitor and the second variable capacitor each include multiple parallel capacitor paths, each capacitor path including a capacitor and a capacitor path switch.

[0012] Secondly, embodiments of this application also provide a control method for a signal loss detection circuit, applied to a control module of the signal loss detection circuit, comprising:

[0013] The signal parameters of the input signal to the preamplifier circuit are detected, and the signal frequency of the input signal is determined based on the signal parameters.

[0014] The threshold value of the common-mode coupling coefficient of the adjustable common-mode coupling module is determined based on the signal frequency;

[0015] The adjustment range of the variable resistor-capacitor combination is determined based on the common-mode coupling coefficient threshold. The variable resistor-capacitor combination is a combination of a single variable resistor and a corresponding single variable capacitor.

[0016] Determine the target resistance and target capacitance values ​​within the adjustment range;

[0017] Adjust the variable resistor and capacitor in each variable resistor-capacitor combination according to the target resistance value and the target capacitance value respectively;

[0018] The common-mode coupling coefficient threshold refers to the threshold value of the common-mode coupling coefficient, which is the product of the resistance value of the variable resistor and the capacitance value of the corresponding variable capacitor in the variable resistor-capacitor combination.

[0019] Optionally, the common-mode coupling coefficient threshold decreases as the signal frequency increases.

[0020] Optionally, the common-mode coupling coefficient threshold includes a first common-mode coupling coefficient threshold and a second common-mode coupling coefficient threshold, wherein the first common-mode coupling coefficient threshold is greater than the second common-mode coupling coefficient threshold; determining the common-mode coupling coefficient threshold of the adjustable common-mode coupling module based on the signal frequency includes: determining the values ​​of the first cutoff frequency threshold and the second cutoff frequency threshold based on the signal transmission protocol and the signal frequency; determining the first common-mode coupling coefficient threshold based on the first cutoff frequency threshold; and determining the second common-mode coupling coefficient threshold based on the second cutoff frequency threshold.

[0021] Optionally, determining the values ​​of the first cutoff frequency threshold and the second cutoff frequency threshold according to the signal transmission protocol and the signal frequency includes: determining the values ​​of the first set value and the second set value according to the signal transmission protocol; calculating the quotient of the signal frequency and the first set value, and using the quotient as the first cutoff frequency threshold; calculating the quotient of the signal frequency and the second set value, and using the quotient as the second cutoff frequency threshold.

[0022] Optionally, determining the adjustment range of the variable resistor-capacitor combination based on the common-mode coupling coefficient threshold includes: determining a common-mode coupling coefficient range that is less than a first common-mode coupling coefficient threshold and greater than a second common-mode coupling coefficient threshold; and determining the adjustment range of the variable resistor-capacitor combination that meets the common-mode coupling coefficient range.

[0023] Thirdly, embodiments of this application also provide an optical receiver, which includes a pre-stage circuit, a signal loss detection circuit, and a post-stage circuit;

[0024] The preamplifier circuit receives the input signal and converts it into a differential signal;

[0025] The pre-stage circuit is connected to the post-stage circuit and the signal loss detection circuit respectively, and inputs the differential signal to the post-stage circuit and the signal loss detection circuit.

[0026] Fourthly, embodiments of this application also provide a control device for a signal loss detection circuit, the device comprising:

[0027] The signal detection module is used to detect the signal parameters of the input signal of the front-end circuit and determine the signal frequency of the input signal based on the signal parameters.

[0028] The threshold determination module is used to determine the common-mode coupling coefficient threshold of the adjustable common-mode coupling module based on the signal frequency.

[0029] The range determination module is used to determine the adjustment range of the variable resistor-capacitor combination based on the common-mode coupling coefficient threshold. The variable resistor-capacitor combination is a combination of a single variable resistor and a corresponding single variable capacitor.

[0030] The numerical determination module is used to determine the target resistance value and the target capacitance value within the adjustment range;

[0031] The control and adjustment module is used to adjust the variable resistor and the variable capacitor in each variable resistor-capacitor combination according to the target resistance value and the target capacitance value, respectively.

[0032] The common-mode coupling coefficient threshold refers to the threshold value of the common-mode coupling coefficient, which is the product of the resistance value of the variable resistor and the capacitance value of the corresponding variable capacitor in the variable resistor-capacitor combination.

[0033] The embodiments of this application bring the following beneficial effects:

[0034] This application provides a signal loss detection circuit and a control method for the signal loss detection circuit. It can determine the common-mode coupling coefficient threshold and the adjustment range of the variable resistor-capacitor combination based on the signal frequency of the input signal. Based on the adjustment range of the variable resistor-capacitor combination, it determines the resistance value of the variable resistor and the capacitance value of the variable capacitor, matching the values ​​of the resistor and capacitor with the signal frequency of the input signal. This avoids the mismatch problem caused by using the same set of resistors and capacitors to detect input signals of different frequencies. Compared with existing signal loss detection circuit control methods, this solves the problems of large LOS delay and low signal loss detection accuracy during signal loss detection.

[0035] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 A schematic diagram of the signal loss detection circuit provided in an embodiment of this application is shown;

[0038] Figure 2 A schematic diagram of the structure of the variable common-mode coupling module provided in an embodiment of this application is shown;

[0039] Figure 3 This is a schematic diagram of the structure of the first variable resistor and the first variable capacitor provided in the embodiments of this application;

[0040] Figure 4A flowchart of the control method for the signal loss detection circuit provided in an embodiment of this application is shown;

[0041] Figure 5 A schematic diagram comparing hysteresis-free and hysteresis-containing LOS signals provided in the embodiments of this application;

[0042] Figure 6 A schematic diagram of the structure of the optical receiver provided in an embodiment of this application is shown;

[0043] Figure 7 A schematic diagram of the control device for the signal loss detection circuit provided in an embodiment of this application is shown. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. Based on the embodiments of this application, every other embodiment obtained by those skilled in the art without inventive effort falls within the scope of protection of this application.

[0045] It is worth noting that prior to this application, in optical data transmission networks, when a signal is transmitted to an optical receiver via a communication channel, it is necessary to quickly and reliably determine whether a signal loss (LOS) has occurred. Optical receivers typically detect signal loss using a lost signal detection circuit. If a signal loss is detected, the optical receiver will issue a "signal loss" alarm or status signal to notify the host system connected to the optical receiver for processing. Traditional LOS detection circuits often use first-order or multi-order resistor-capacitor (RC) filter circuits to filter the optical signal and threshold signal before inputting them to a subsequent comparator for amplitude comparison, thereby determining whether a signal loss has occurred. However, in traditional signal loss detection methods, the resistor and capacitor values ​​are fixed and cannot be matched for different signal frequencies, resulting in large LOS delays and low signal loss detection accuracy. For example, when monitoring low-frequency signals, a larger RC value is required; otherwise, voltage drift is likely to occur when the signal shows a long 0 or long 1. If the effect is eliminated by adding a filter capacitor, it will increase the LOS delay. When detecting high-frequency signals, the circuit needs a longer time to establish the common-mode voltage when using a larger RC circuit, which increases the LOS delay. Therefore, a smaller RC circuit is required.

[0046] Based on this, embodiments of this application provide a signal loss detection circuit to reduce LOS delay and improve the accuracy of signal loss detection.

[0047] Please see Figure 1 , Figure 1 This is a schematic diagram of a signal loss detection circuit provided in an embodiment of this application. Figure 1 As shown, the signal loss detection circuit provided in this application embodiment includes a common-mode voltage generation module 210, a peak detection module 220, a mirror peak detection module 230, a comparator 240, a control module 250, and an adjustable common-mode coupling module 260.

[0048] The signal loss detection circuit receives the differential signal output from the previous stage circuit. After passing through the adjustable common-mode coupling module 260, the differential signal is input to the peak detection module to generate the peak signal.

[0049] The common-mode voltage generation module 210 is used to generate a common-mode voltage and a reference common-mode voltage, and outputs the common-mode voltage to the adjustable common-mode coupling module 260, and outputs the reference common-mode voltage to the mirror peak detection module 230 to generate a reference peak signal;

[0050] Comparator 240 serves as the output of the signal loss detection circuit, receiving the peak signal and the reference peak signal, and outputting the LOS signal based on the comparison result.

[0051] The control module 250 is connected to the input terminal of the adjustable common-mode coupling module 260, the input terminal of the common-mode voltage generation module 210, and the output terminal of the signal loss detection circuit, respectively. It detects the signal parameters of the input signal of the preceding circuit and adjusts the adjustable common-mode coupling module 260 based on the signal parameters.

[0052] In this embodiment, the input signal is converted into a differential signal after passing through the pre-amplifier circuit. The first output terminal of the pre-amplifier circuit is connected to the first input terminal of the adjustable common-mode coupling module 260, and the second output terminal of the pre-amplifier circuit is connected to the second input terminal of the adjustable common-mode coupling module 260. The differential signal is input to the adjustable common-mode coupling module 260. The output terminal of the adjustable common-mode coupling module 260 is connected to the input terminal of the peak detection module 220. The signal output by the adjustable common-mode coupling module 260 is converted into a peak signal (VPEAK signal) after passing through the peak detection module 220. The output terminal of the peak detection module 220 is connected to the first input terminal of the comparator 240, and the peak signal is input to the comparator 240.

[0053] The input terminal of the common-mode voltage generation module 210 is connected to the output terminal of the control module 250. It obtains the target threshold, common-mode control signal (VCOM_CTRL), and hysteresis from the control module 250, and determines the common-mode voltage and reference common-mode voltage based on the obtained data. The output terminals of the common-mode voltage generation module 210 include a first output terminal and a second output terminal. The first output terminal of the common-mode voltage generation module 210 is connected to the third input terminal of the adjustable common-mode coupling module 260, inputting the common-mode voltage to the adjustable common-mode coupling module 260. The second output terminal of the common-mode voltage generation module 210 is connected to the input terminal of the image peak detection module 230, inputting the reference common-mode voltage to the image peak detection module 230. The target threshold is either a set threshold or a clear threshold.

[0054] The input terminal of the control module 250 is connected to the output terminal of the register, which includes a first register 271, a second register 272, and a third register 273. The control module 250 obtains the target threshold THRESHOLD from the first register 271. This target threshold THRESHOLD includes a set threshold or a clear threshold; the set threshold is denoted as LOS_ASSERT_THRESHOLD, and the clear threshold is denoted as LOS_DEASSERT_THRESHOLD. The common-mode voltage generation module 210 obtains the hysteresis HYSTERESIS from the second register 272. The common-mode voltage generation circuit obtains the common-mode control signal VCOM_CTRL from the third register 273. Specifically, register 271 stores either LOS_ASSERT_THRESHOLD or LOS_DEASSERT_THRESHOLD, register 272 stores HYSTERESIS, and register 273 stores VCOM_CTRL. The common-mode voltage generation module 210 obtains the common-mode voltage control signal VCOM_CTRL from register 273 and uses VCOM_CTRL to control the common-mode voltage output by the module. LOS_ASSERT_THRESHOLD and LOS_DEASSERT_THRESHOLD will be described later and will not be repeated here.

[0055] The common-mode voltage generation module 210 generates a common-mode voltage VCOM and a reference common-mode voltage VCOM_REF based on the acquired THRESHOLD, HYSTERESIS, and VCOM_CTRL. The common-mode voltage is then input to the adjustable common-mode coupling module 260, and the reference common-mode voltage is input to the image peak detection module 230 to generate a reference peak signal VPEAK_REF. The output of the image peak detection module 230 is connected to the second input of the comparator 240, and the reference peak signal is input to the comparator 240.

[0056] Comparator 240 receives the peak signal and the reference peak signal, compares the received peak signal and the reference peak signal, and outputs the LOS signal based on the comparison result.

[0057] The input terminal of the control module 250 receives the input signal, detects the signal parameters of the input signal, and adjusts the adjustable common-mode coupling module 260 based on the detection results. The input terminal of the control module 250 is also connected to the output terminal of the signal loss detection circuit, receiving the LOS signal from the output terminal and hysteret-adjusting the reference common-mode voltage based on the LOS signal level changes. The output terminal of the control module 250 is connected to the fourth input terminal of the adjustable common-mode coupling module 260. The control module 250 detects the signal parameters of the input signal from the preceding circuit and adjusts the adjustable common-mode coupling module 260 based on these signal parameters.

[0058] In one optional embodiment, the adjustable common-mode coupling module includes: a first variable capacitor, a first variable resistor, a second variable capacitor, and a second variable resistor; one end of the first variable capacitor receives a differential signal, the other end of the first variable capacitor is connected to one end of the first variable resistor, and the other end of the first variable capacitor also serves as the first output terminal of the adjustable common-mode coupling module and is connected to the first input terminal of the peak detection module; one end of the second variable capacitor receives a differential signal, the other end of the second variable capacitor is connected to one end of the second variable resistor, and the other end of the second variable capacitor also serves as the second output terminal of the adjustable common-mode coupling module and is connected to the second input terminal of the peak detection module; the other ends of the first variable resistor and the second variable resistor are respectively connected to the common-mode voltage generation module.

[0059] The following reference Figure 2 Let's introduce the adjustable common-mode coupling module.

[0060] Figure 2 A schematic diagram of the structure of the variable common-mode coupling module provided in an embodiment of this application is shown.

[0061] like Figure 2As shown, the variable common-mode coupling module includes a first variable capacitor C1, a second variable capacitor C2, a first variable resistor R1, and a second variable resistor R2. The first terminal of the first variable capacitor C1 serves as the first input terminal of the adjustable common-mode coupling module, and the first terminal of the second variable capacitor C2 serves as the second input terminal. The first terminal of the first variable capacitor C1 is connected to the first output terminal of the preceding stage circuit, and the first terminal of the second variable capacitor C2 is connected to the second output terminal of the preceding stage circuit. The second terminals of the first and second variable capacitors C1 and C2 serve as the first and second output terminals of the adjustable common-mode coupling module, respectively, and are connected to the first and second input terminals of the peak detection module 220, respectively. The second terminal of the first variable capacitor C1 is connected to the first terminal of the first variable resistor R1, and the second terminal of the second variable capacitor C2 is connected to the first terminal of the second variable resistor R2. The second terminals of both the first and second variable resistors R1 and R2 are connected to the first output terminal of the common-mode voltage generation module 210. The first variable capacitor C1, the second variable capacitor C2, the first variable resistor R1, and the second variable resistor R2 are also connected to the input terminal of the control module to adjust the capacitance value of the variable capacitor and the resistance value of the variable resistor according to the input of the control module.

[0062] Here, the input signal is split into two paths after matching by the pre-stage circuit. One path enters the subsequent stage circuit (limiting amplifier) ​​and outputs data, while the other path passes through the signal loss detection circuit and outputs a LOS signal. In the signal loss detection circuit, the differential signal passes through the first variable capacitor C1 and the second variable capacitor C2 respectively before entering the peak detection circuit to obtain the VPEAK signal. This VPEAK signal is a voltage that characterizes the signal amplitude; it is positively correlated with the signal amplitude but not equal to it. The signal amplitude refers to the peak value of the differential signal of the input signal.

[0063] Simultaneously, the common-mode voltage generation circuit generates a common-mode voltage (VCOM) and a common-mode reference voltage VCOM_REF associated with VCOM. VCOM is input to the peak detection circuit after passing through the first variable resistor R1 and the second variable resistor R2. Therefore, the output voltage VPEAK of the peak detection circuit is affected by the amplitude of the received signal and the common-mode voltage (VCOM). VCOM_REF is then output as VPEAK_REF after passing through a mirror peak detection circuit that is identical to the peak detection circuit. VPEAK is then compared with VPEAK_REF. The comparator determines whether there is signal loss based on whether the amplitude of the input signal meets the requirements. If the LOS output of the comparator is high, it indicates that the detection result is a signal loss; if the LOS output of the comparator is low, it indicates that the detection result is no signal loss. This reduces the impact of different process corners, power supply voltages, and temperatures (PVT), ensuring the consistency of the LOS circuit output under various environments.

[0064] The control signal input from the control module to the variable common-mode coupling module can not only adjust the capacitance values ​​of the first and second variable capacitors in the adjustable common-mode coupling module, but also adjust the resistance values ​​of the first and second variable resistors. This allows it to be used for the detection of signals at different rates, improving the reliability of detection and reducing LOS delay.

[0065] In one optional embodiment, the first variable resistor and the second variable resistor each include a plurality of parallel resistor paths, each resistor path including a resistor and a resistor path switch; the first variable capacitor and the second variable capacitor each include a plurality of parallel capacitor paths, each capacitor path including a capacitor and a capacitor path switch.

[0066] The following is based on Figure 3 This section will introduce the specific structures of variable resistors and variable capacitors.

[0067] Figure 3 This is a schematic diagram of the structure of the first variable resistor and the first variable capacitor provided in the embodiments of this application.

[0068] like Figure 3 As shown, the first variable resistor consists of four parallel resistor paths. The first resistor path includes resistor R1_1 and resistor path switch S1; the second resistor path includes resistor R1_2 and resistor path switch S2; the third resistor path includes resistor R1_3 and resistor path switch S3; and the fourth resistor path includes resistor R1_4 and resistor path switch S4. Resistors R1_1, R1_2, R1_3, and R1_4 are all 8kΩ.

[0069] The first variable capacitor consists of two parallel capacitor paths. The first capacitor path includes capacitor C1_1 and capacitor path switch S5, and the second capacitor path includes capacitor C1_2 and capacitor path switch S6. Capacitor C1_1 has a capacitance of 1pF, and capacitor C1_2 has a capacitance of 0.5pF.

[0070] The above are just specific examples of the implementation method. The closing or opening of each switch is not fixed. In specific implementations, the state of each switch can be configured through registers for signal rates of 2.5GHz and 10GHz. The control module controls different closing states of S1, S2, S3, and S4 to obtain different resistance values, and controls different closing states of S5 and S6 to obtain different capacitance values, in order to adapt to the influence of environmental changes, as long as the cutoff frequency f is met. L <Signal rate / 72 is sufficient.

[0071] Please see Figure 4 , Figure 4 This is a flowchart illustrating a control method for a signal loss detection circuit provided in an embodiment of this application. Figure 4 As shown, the control method for the signal loss detection circuit is applied to the control module of the signal loss detection circuit, and the method includes:

[0072] Step S101: Detect the signal parameters of the input signal of the pre-amplifier circuit, and determine the signal frequency of the input signal based on the signal parameters.

[0073] In this step, the input signal can refer to the optical signal received by the optical receiver. For example, the input signal can be a signal with a frequency of 2.5 GHz, a signal with a frequency of 10 GHz, or a signal of other frequencies.

[0074] Signal parameters can refer to the parameters of the input signal, including but not limited to: signal frequency, signal rate, and rate indication signal.

[0075] In this embodiment, the control module detects the input signal and obtains the signal parameters of the input signal, such as the signal rate of the input signal, and then determines the signal frequency based on the signal rate.

[0076] If the rate indicator signal corresponding to the input signal is detected to be high, the current transmitted signal frequency is determined to be 2.5 GHz. If the rate indicator signal corresponding to the input signal is detected to be low, the current transmitted signal frequency is determined to be 10 GHz. The rate indicator signal is used to indicate the signal frequency of the input signal.

[0077] Step S102: Determine the common-mode coupling coefficient threshold of the adjustable common-mode coupling module based on the signal frequency.

[0078] In this step, the common-mode coupling coefficient threshold refers to the threshold value of the common-mode coupling coefficient, which is the product of the resistance value of the variable resistor and the capacitance value of the corresponding variable capacitor in the variable resistor-capacitor combination.

[0079] In one optional embodiment, the common-mode coupling coefficient threshold includes a first common-mode coupling coefficient threshold and a second common-mode coupling coefficient threshold, wherein the first common-mode coupling coefficient threshold is greater than the second common-mode coupling coefficient threshold; determining the common-mode coupling coefficient threshold of the adjustable common-mode coupling module based on the signal frequency includes: determining the values ​​of a first cutoff frequency threshold and a second cutoff frequency threshold based on the signal transmission protocol and the signal frequency; determining the first common-mode coupling coefficient threshold based on the first cutoff frequency threshold; and determining the second common-mode coupling coefficient threshold based on the second cutoff frequency threshold.

[0080] Here, the first common-mode coupling coefficient threshold can refer to the upper limit of the product of the resistance value of the variable resistor and the capacitance value of the variable capacitor.

[0081] The second common-mode coupling coefficient threshold can refer to the lower limit of the product of the resistance value of the variable resistor and the capacitance value of the variable capacitor.

[0082] The first cutoff frequency threshold can refer to the upper limit of the cutoff frequency, and the second cutoff frequency threshold can refer to the lower limit of the cutoff frequency.

[0083] For example, the first cutoff frequency threshold can be 35MHz, and the second cutoff frequency threshold can be 10MHz.

[0084] Specifically, the values ​​of the first cutoff frequency threshold and the second cutoff frequency threshold are first determined. Since the cutoff frequency = 1 / (2π×R×C), the first common-mode coupling coefficient threshold = 1 / (2π×first cutoff frequency threshold) and the second common-mode coupling coefficient threshold = 1 / (2π×second cutoff frequency threshold).

[0085] In one optional embodiment, determining the values ​​of the first cutoff frequency threshold and the second cutoff frequency threshold according to the signal transmission protocol and the signal frequency includes: determining the values ​​of the first set value and the second set value according to the signal transmission protocol; calculating the quotient of the signal frequency and the first set value, and using the quotient as the first cutoff frequency threshold; calculating the quotient of the signal frequency and the second set value, and using the quotient as the second cutoff frequency threshold.

[0086] Specifically, to reduce the impact of voltage drift during the 72 consecutive 0s or 1s specified in the transmission protocol, the range of the cutoff frequency needs to be limited. Here, according to the transmission protocol, a second setting value greater than or equal to 72 can be selected. Taking a second setting value of 72 and a signal frequency of 2.5GHz as an example, the second cutoff frequency threshold = 2.5GHz / 72 = 35MHz; taking a signal frequency of 10GHz as an example, the second cutoff frequency threshold = 10GHz / 72 = 140MHz.

[0087] Meanwhile, to avoid introducing low-frequency noise from the power supply and excessively long common-mode setup time, the cutoff frequency cannot be too small. Therefore, a first cutoff frequency threshold is introduced. Taking a first setpoint of 1000 and a signal frequency of 2.5GHz as an example, the first cutoff frequency threshold = 2.5GHz / 1000 = 2.56MHz; taking a first setpoint of 100 and a signal frequency of 10GHz as an example, the first cutoff frequency threshold = 10GHz / 100 = 100MHz. It should be noted that the first setpoint is different for different input signals.

[0088] In an alternative embodiment, the common-mode coupling coefficient threshold decreases as the signal frequency increases.

[0089] Specifically, due to the cutoff frequency f L =1 / (2π×R×C), where R×C represents the common-mode coupling coefficient. From the above formula, we can see that the common-mode coupling coefficient is inversely proportional to the cutoff frequency. When the cutoff frequency is directly proportional to the signal frequency, the common-mode coupling coefficient threshold is inversely proportional to the signal frequency. That is, the common-mode coupling coefficient threshold decreases as the signal frequency increases.

[0090] Step S103: Determine the adjustment range of the variable resistor-capacitor combination based on the common-mode coupling coefficient threshold.

[0091] In this step, the variable resistor-capacitor combination is a combination of a single variable resistor and a corresponding single variable capacitor. For example, the first variable resistor and the first variable capacitor are combined to form a variable resistor-capacitor combination, and the second variable resistor and the second variable capacitor are combined to form a variable resistor-capacitor combination.

[0092] The adjustment range of a variable resistor-capacitor combination refers to the adjustment range of the resistance value of the variable resistor and the capacitance value of the variable capacitor.

[0093] In one optional embodiment, determining the adjustment range of the variable resistor-capacitor combination based on the common-mode coupling coefficient threshold includes: determining a common-mode coupling coefficient range that is less than a first common-mode coupling coefficient threshold and greater than a second common-mode coupling coefficient threshold; and determining the adjustment range of the variable resistor-capacitor combination that meets the common-mode coupling coefficient range.

[0094] Specifically, the first cutoff frequency threshold is denoted as f. LMIN The second cutoff frequency threshold is denoted as f. LMAX Due to the cutoff frequency f L =1 / (2π×R×C), then the threshold for the first common-mode coupling coefficient is 1 / (2πf LMON The threshold for the second common-mode coupling coefficient is 1 / (2πf). LMAX The common-mode coupling coefficient range can be determined to be (1 / (2πf)). LMAX ),1 / (2πf LMIN )).

[0095] After determining the common-mode coupling coefficient range, the adjustment ranges of the variable resistor and variable capacitor in each variable resistor-capacitor combination can be determined separately. Here, since the variable resistor is composed of multiple parallel resistor paths, given the resistance value of each resistor in the path, a list of all possible resistance values ​​for the variable resistor can be determined. Similarly, given the capacitance value of each capacitor in the capacitor path, a list of all possible capacitance values ​​for the variable capacitor can be determined. For each variable resistor-capacitor combination, the corresponding resistance value list and the capacitance and resistance values ​​in the capacitance value list that satisfy the common-mode coupling coefficient range are taken as the adjustment range of that variable resistor-capacitor combination.

[0096] Step S104: Determine the target resistance value and target capacitance value within the adjustment range.

[0097] The target resistance value can refer to the resistance value that the variable resistor is expected to achieve in order to match the signal frequency of the input signal.

[0098] The target capacitance value can refer to the resistance value that the variable capacitor is expected to achieve in order to match the signal frequency of the input signal.

[0099] In this embodiment, since the adjustment range is determined based on the signal frequency of the input signal, different input signals correspond to different adjustment ranges. Target resistance and target capacitance values ​​that match the signal frequency of the input signal can be obtained, so that the variable resistance and variable capacitance in the signal loss detection circuit can be adjusted according to the target resistance and target capacitance values.

[0100] Specifically, after determining the adjustment range, select the resistance value and the capacitance value that meet the preset conditions and satisfy the adjustment range from the resistance value list and the capacitance value list, respectively, as the target resistance value and the target capacitance value.

[0101] For a 2.5GHz input signal, a preset condition could be to maximize the common-mode coupling coefficient, as larger resistance and capacitance values ​​result in a shorter LOS delay. Another preset condition could be to maximize the value of the variable resistor, with the variable capacitor determined based on the variable resistor value. For a 10GHz input signal, a preset condition could be to minimize the common-mode coupling coefficient, as larger resistance and capacitance values ​​cause the two input signals of the peak detection circuit to be unequal, requiring a longer LOS time to return to 0. Another preset condition could be to minimize the value of the variable resistor, with the variable capacitor determined based on the variable resistor value.

[0102] Step S105: Adjust the variable resistor and variable capacitor in each variable resistor-capacitor combination according to the target resistance value and the target capacitance value.

[0103] In this step, for each variable resistor, its resistance value is adjusted to the target resistance value; similarly, for each variable capacitor, its capacitance value is adjusted to the target capacitance value. In this way, the resistance values ​​of the variable resistors and the capacitance values ​​of the variable capacitors in the signal loss detection circuit are matched to the signal frequency of the input signal, reducing the impact of LOS delay and providing high accuracy in signal loss detection.

[0104] For each variable resistor, the on / off state of each resistor path switch corresponding to the target resistance value is determined based on the resistance value of each resistor in the variable resistor; for each resistor path switch in the variable resistor, the resistor path switch is controlled to open or close according to the corresponding on / off state; for each variable capacitor, the on / off state of each capacitor path switch corresponding to the target capacitance value is determined based on the capacitance value of each capacitor in the variable capacitor; for each capacitor path switch in the variable capacitor, the capacitor path switch is controlled to open or close according to the corresponding on / off state.

[0105] Taking the first variable resistor as an example, based on the resistance value of each resistor in the first variable resistor, the opening and closing states of the switches of each resistor path in the first variable resistor are adjusted to achieve the effect that the resistance value of the first variable resistor is equal to the target resistance value. Similarly, taking the first variable capacitor as an example, based on the capacitance value of each capacitor in the first variable capacitor, the opening and closing states of the switches of each capacitor path in the first variable capacitor are adjusted to achieve the effect that the capacitance value of the first variable capacitor is equal to the target capacitance value.

[0106] Taking the above example as an instance, if it is detected that the rate indication signal corresponding to the input signal is at a high level, it is determined that the frequency of the currently transmitted signal is 2.5 GHz. At this time, the signal loss detection circuit requires a relatively large RC. Assuming that the calculated target resistance value is 8 kΩ and the target capacitance value is 1 pF, the switches S1 and S5 can be controlled to close, and the switches S2, S3, S4 and S6 can be controlled to open. At this time, the resistance value of the first variable resistor is 8 kΩ, the first variable capacitor is 1 pF, and the -3 dB cutoff frequency f L =1 / (2π×8kΩ×1pF)=20MHz. Since 20 MHz is less than the first common-mode coupling coefficient threshold of 30 MHz, the influence of voltage drift can be reduced. At this time, the filter capacitor C3 after the peak detection circuit can use 1 / 3 of the original capacitance value to achieve filtering, thereby reducing the LOS delay.

[0107] If it is detected that the rate indication signal corresponding to the input signal is at a low level, it is determined that the frequency of the currently transmitted signal is 10 GHz. At this time, the signal loss detection circuit requires a relatively small RC. Assuming that the calculated target resistance value is 2 kΩ and the target capacitance value is 1 pF, the switches S1, S2, S3, S4 and S5 can be controlled to close, and the switch S6 can be controlled to open. The cutoff frequency f L =1 / (2π×2kΩ×1pF)=80MHz. Since 80 MHz is less than the first common-mode coupling coefficient threshold of 140 MHz, while meeting the requirement that no voltage drift is generated for 72 consecutive 0s or 1s specified by the transmission protocol, the circuit can quickly establish a common mode, and the LOS delay is reduced.

[0108] In addition, hysteresis adjustment can also be performed on the reference common-mode voltage according to the received LOS signal.

[0109] In the following, referring to Figure 5 the hysteresis of the LOS signal is introduced.

[0110] Figure 5 is a schematic diagram of comparison between a non-hysteretic LOS signal and a hysteretic LOS signal provided by the embodiments of the present application.

[0111] As shown in Figure 5 under an ideal condition without considering the influence of other factors such as noise, that is, under an ideal signal, the reference voltage VPEAK_REF remains unchanged, and the voltage VPEAK representing the signal amplitude is only related to the signal amplitude. The larger the signal amplitude, the larger the VPEAK. When VPEAK<VPEAK_REF, the LOS signal output by the comparator COMP is at a high level. As the signal amplitude increases, when VPEAK>VPEAK_REF, the LOS signal output by the comparator COMP is at a low level.

[0112] Under ideal conditions, when VPEAK is close to VPEAK_REF, LOS will not jitter. However, when considering that VPEAK is disturbed by noise (for the convenience of description, it is only assumed here that VPEAK is disturbed by noise, such as Figure 4 the two schematic diagrams below in), the LOS signal will jitter, that is, when VPEAK is close to VPEAK_REF, the case of VPEAK < VPEAK_REF may occur sometimes, and the case of VPEAK > VPEAK_REF may also occur sometimes, causing LOS to toggle between a low level and a high level.

[0113] If after the LOS signal changes from a high level to a low level, the value of VPEAK_REF can be reduced through the configuration of the signal loss detection circuit, resulting in that VPEAK is always greater than VREF even if there is noise interference, then the LOS signal will remain at the low level, instead of toggling between the low level and the high level. Similarly, if after the LOS signal changes from a low level to a high level, the value of VPEAK_REF can be increased through the configuration of the signal loss detection circuit.

[0114] The process in which the LOS signal changes from a low level to a high level is referred to as LOS ASSERT. At this time, the signal amplitude needs to be set to be less than a set threshold, and this set threshold is referred to as LOS_ASSERT_THRESHOLD. The process in which the LOS signal changes from a high level to a low level is referred to as LOS DEASSERT. At this time, the signal amplitude needs to be set to be greater than a clear threshold, and this clear threshold is referred to as LOS_DEASSERT_THRESHOLD, and HYSTERESIS is referred to as hysteresis.

[0115] In the embodiments of the present application, the value of LOS_ASSERT_THRESHOLD or LOS_DEASSERT_THRESHOLD may be configured through the first register 271, and the value of HYSTERESIS may be configured through the second register 272. If LOS_ASSERT_THRESHOLD is configured in the first register 271, the value of LOS_DEASSERT_THRESHOLD may be calculated using the following formula; conversely, if LOS_DEASSERT_THRESHOLD is configured in the first register 271, the value of LOS_ASSERT_THRESHOLD may be calculated using the following formula, where the calculation formula is:

[0116]

[0117] Specifically, the comparator's output is also connected to the control module's input, used to input the LOS signal to the control module so that the set hysteresis can be adjusted when the LOS signal oscillates. That is, if the input signal is normal and the signal loss detection circuit is working properly, but the LOS signal keeps oscillating, it means that the hysteresis setting is too small and a larger hysteresis setting is needed.

[0118] Compared with the signal loss detection circuit control method in the prior art, this application can determine the common-mode coupling coefficient threshold and the adjustment range of the variable resistor and capacitor combination according to the signal frequency of the input signal. Based on the adjustment range of the variable resistor and capacitor combination, the resistance value of the variable resistor and the capacitance value of the variable capacitor are determined. The values ​​of the resistor and capacitor are matched with the signal frequency of the input signal, avoiding the mismatch problem caused by using the same set of resistors and capacitors to detect input signals with different signal frequencies. This solves the problems of large LOS delay and low signal loss detection accuracy in the process of signal loss detection.

[0119] Please see Figure 6 , Figure 6 An optical receiver is provided as an embodiment of this application. For example... Figure 6 As shown, the optical receiver 10 includes a front-end circuit 100, a signal loss detection circuit 200, and a back-end circuit 300;

[0120] The preamplifier circuit 100 receives the input signal and converts it into a differential signal;

[0121] The preamplifier circuit 100 is connected to the cascade circuit 300 and the signal loss detection circuit 200 respectively, and inputs the differential signal to the cascade circuit 300 and the signal loss detection circuit 200.

[0122] Based on the same inventive concept, this application also provides a control device for a signal loss detection circuit corresponding to the control method for the signal loss detection circuit. Since the principle of the device in this application is similar to the control method for the signal loss detection circuit described above in this application, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be described again.

[0123] Please see Figure 7 , Figure 7 This is a schematic diagram of the control device for a signal loss detection circuit provided in an embodiment of this application. Figure 7 As shown, the control device 400 of the signal loss detection circuit includes:

[0124] The signal detection module 401 is used to detect the signal parameters of the input signal of the front-end circuit and determine the signal frequency of the input signal based on the signal parameters.

[0125] The threshold determination module 402 is used to determine the common-mode coupling coefficient threshold of the adjustable common-mode coupling module based on the signal frequency;

[0126] The range determination module 403 is used to determine the adjustment range of the variable resistor-capacitor combination based on the common-mode coupling coefficient threshold. The variable resistor-capacitor combination is a combination of a single variable resistor and a corresponding single variable capacitor.

[0127] The numerical determination module 404 is used to determine the target resistance value and the target capacitance value within the adjustment range;

[0128] The control and adjustment module 405 is used to adjust the variable resistance and variable capacitor in each variable resistance and capacitor combination according to the target resistance value and the target capacitance value respectively.

[0129] The common-mode coupling coefficient threshold refers to the threshold value of the common-mode coupling coefficient, which is the product of the resistance value of the variable resistor and the capacitance value of the corresponding variable capacitor in the variable resistor-capacitor combination.

[0130] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0131] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the shown or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0132] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0133] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0134] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0135] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The scope of protection of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the scope of the technology disclosed in this application. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A signal loss detection circuit, characterized in that, The signal loss detection circuit includes an adjustable common-mode coupling module, a common-mode voltage generation module, a peak detection module, a mirror peak detection module, a comparator, and a control module. The signal loss detection circuit receives the differential signal output from the preceding circuit. The differential signal passes through the adjustable common-mode coupling module and is then input into the peak detection module to generate a peak signal. The common-mode voltage generation module is used to generate a common-mode voltage and a reference common-mode voltage, and outputs the common-mode voltage to the adjustable common-mode coupling module, and outputs the reference common-mode voltage to the mirror peak detection module to generate a reference peak signal; The comparator serves as the output of the signal loss detection circuit, receives the peak signal and the reference peak signal, and outputs a LOS signal based on the comparison result. The control module is connected to the input terminal of the adjustable common-mode coupling module, the input terminal of the common-mode voltage generation module, and the output terminal of the signal loss detection circuit, respectively. It detects the signal parameters of the input signal of the front-end circuit and adjusts the adjustable common-mode coupling module based on the signal parameters. The control module is specifically used for: The signal parameters of the input signal of the front-end circuit are detected, and the signal frequency of the input signal is determined based on the signal parameters; The common-mode coupling coefficient threshold of the adjustable common-mode coupling module is determined based on the signal frequency; The adjustment range of the variable resistor-capacitor combination is determined based on the common-mode coupling coefficient threshold. The variable resistor-capacitor combination is a combination of a single variable resistor and a corresponding single variable capacitor. Determine the target resistance value and target capacitance value within the aforementioned adjustment range; Adjust the variable resistor and variable capacitor in each variable resistor-capacitor combination according to the target resistance value and the target capacitance value respectively; The common-mode coupling coefficient threshold refers to the threshold value of the common-mode coupling coefficient, which is the product of the resistance value of the variable resistor and the capacitance value of the corresponding variable capacitor in the variable resistor-capacitor combination. The target resistance value can refer to the resistance value that the variable resistor is expected to achieve in order to match the signal frequency of the input signal, and the target capacitance value can refer to the resistance value that the variable capacitor is expected to achieve in order to match the signal frequency of the input signal.

2. The signal loss detection circuit according to claim 1, characterized in that, The adjustable common-mode coupling module includes: a first variable capacitor, a first variable resistor, a second variable capacitor, and a second variable resistor; One end of the first variable capacitor receives the differential signal, and the other end of the first variable capacitor is connected to one end of the first variable resistor. The other end of the first variable capacitor is also connected to the first input end of the adjustable common-mode coupling module as the first output end of the peak detection module. One end of the second variable capacitor receives the differential signal, and the other end of the second variable capacitor is connected to one end of the second variable resistor. The other end of the second variable capacitor is also connected to the second input terminal of the peak detection module as the second output terminal of the adjustable common-mode coupling module. The other ends of the first variable resistor and the second variable resistor are respectively connected to the common-mode voltage generation module.

3. The signal loss detection circuit according to claim 2, characterized in that, The first variable resistor and the second variable resistor each include a plurality of parallel resistor paths, and each resistor path includes a resistor and a resistor path switch; The first variable capacitor and the second variable capacitor each include a plurality of parallel capacitor paths, and each capacitor path includes a capacitor and a capacitor path switch.

4. A control method for a signal loss detection circuit, applied to the control module of the signal loss detection circuit as described in any one of claims 1 to 3, characterized in that, include: The signal parameters of the input signal of the front-end circuit are detected, and the signal frequency of the input signal is determined based on the signal parameters; The common-mode coupling coefficient threshold of the adjustable common-mode coupling module is determined based on the signal frequency; The adjustment range of the variable resistor-capacitor combination is determined based on the common-mode coupling coefficient threshold. The variable resistor-capacitor combination is a combination of a single variable resistor and a corresponding single variable capacitor. Determine the target resistance value and target capacitance value within the aforementioned adjustment range; Adjust the variable resistor and variable capacitor in each variable resistor-capacitor combination according to the target resistance value and the target capacitance value respectively; The common-mode coupling coefficient threshold refers to the threshold value of the common-mode coupling coefficient, which is the product of the resistance value of the variable resistor and the capacitance value of the corresponding variable capacitor in the variable resistor-capacitor combination. The target resistance value can refer to the resistance value that the variable resistor is expected to achieve in order to match the signal frequency of the input signal, and the target capacitance value can refer to the resistance value that the variable capacitor is expected to achieve in order to match the signal frequency of the input signal.

5. The control method according to claim 4, characterized in that, The common-mode coupling coefficient threshold decreases as the signal frequency increases.

6. The control method according to claim 4, characterized in that, The common-mode coupling coefficient threshold includes a first common-mode coupling coefficient threshold and a second common-mode coupling coefficient threshold, and the first common-mode coupling coefficient threshold is greater than the second common-mode coupling coefficient threshold; Determining the common-mode coupling coefficient threshold of the adjustable common-mode coupling module based on the signal frequency includes: The values ​​of the first cutoff frequency threshold and the second cutoff frequency threshold are determined according to the signal transmission protocol and the signal frequency. The first common-mode coupling coefficient threshold is determined based on the first cutoff frequency threshold. The second common-mode coupling coefficient threshold is determined based on the second cutoff frequency threshold.

7. The control method according to claim 6, characterized in that, The step of determining the values ​​of the first cutoff frequency threshold and the second cutoff frequency threshold according to the signal transmission protocol and the signal frequency includes: The values ​​of the first set value and the second set value are determined according to the signal transmission protocol; Calculate the quotient between the signal frequency and the first set value, and use the quotient as the first cutoff frequency threshold. Calculate the quotient between the signal frequency and the second set value, and use the quotient as the second cutoff frequency threshold.

8. The control method according to claim 6, characterized in that, The step of determining the adjustment range of the variable resistor-capacitor combination based on the common-mode coupling coefficient threshold includes: Determine the range of common-mode coupling coefficients that are less than the first common-mode coupling coefficient threshold and greater than the second common-mode coupling coefficient threshold; Determine the adjustment range of the variable resistor-capacitor combination that satisfies the common-mode coupling coefficient range.

9. An optical receiver, characterized in that, Includes the signal loss detection circuit, the front-end circuit, and the rear-end circuit as described in any one of claims 1 to 3; The front-end circuit receives the input signal and converts the input signal into a differential signal; The pre-stage circuit is connected to the post-stage circuit and the signal loss detection circuit respectively, and inputs the differential signal to the post-stage circuit and the signal loss detection circuit.

10. A control device for a signal loss detection circuit, characterized in that, include: The signal detection module is used to detect the signal parameters of the input signal of the front-end circuit and determine the signal frequency of the input signal based on the signal parameters. A threshold determination module is used to determine the common-mode coupling coefficient threshold of the adjustable common-mode coupling module based on the signal frequency; The range determination module is used to determine the adjustment range of the variable resistor-capacitor combination based on the common-mode coupling coefficient threshold, wherein the variable resistor-capacitor combination is a combination of a single variable resistor and a corresponding single variable capacitor. The numerical determination module is used to determine the target resistance value and the target capacitance value within the adjustment range. The target resistance value can refer to the resistance value that the variable resistor is expected to achieve in order to match the signal frequency of the input signal, and the target capacitance value can refer to the resistance value that the variable capacitor is expected to achieve in order to match the signal frequency of the input signal. The control and adjustment module is used to adjust the variable resistance and the variable capacitor in each variable resistance and variable capacitor combination according to the target resistance value and the target capacitance value, respectively. The common-mode coupling coefficient threshold refers to the threshold value of the common-mode coupling coefficient, which is the product of the resistance value of the variable resistor and the capacitance value of the corresponding variable capacitor in the variable resistor-capacitor combination.

Images