Equalizer tunable circuit, amplifier tunable circuit, and electronic device

Abstract

The utility model provides an equalizer adjustable circuit, an amplifier adjustable circuit and electronic equipment, and belongs to the technical field of equalizers. And the cross negative impedance module is used for compensating the input signal through negative impedance. And the adjustable current module is connected with the cross negative impedance module. And the adjustable current module is used for providing adjustable bias current for the cross negative impedance module so as to adjust the negative impedance generated by the cross negative impedance module through the adjustable bias current. By adjusting the current of the adjustable current module, the bias current of the cross negative impedance module can be adjusted, and then the negative impedance generated by the cross negative impedance module can be adjusted, so that the loss of the circuit and the frequency response characteristic can be optimized in bandwidth, gain, peak point and peak amplitude; the technical problem that a traditional equalizer circuit cannot adjust the circuit gain is solved, so that the circuit can achieve the equalization effect, and input signals are compensated and equalized.

Description

Technical Field

[0001] This application belongs to the technical field of equalizers, and particularly relates to an adjustable equalizer circuit, an adjustable amplifier circuit, and an electronic device. Background Art

[0002] A continuous time linear equalizer (CTLE) is an analog filter. By adjusting the parameters of the circuit, the CTLE compensates for the attenuation of high-frequency components after the signal is transmitted through the channel, thereby improving the signal quality, effectively reducing inter-symbol interference, and increasing the transmission rate and reliability of the signal.

[0003] However, in the traditional equalizer circuit, the frequency peak amplitude is changed by changing the capacitance, but the gain of the equalizer circuit remains unchanged. Therefore, the gain of the circuit cannot be adjusted by the traditional equalizer circuit. Summary of the Utility Model

[0004] The purpose of this application is to provide an adjustable equalizer circuit, an adjustable amplifier circuit, and an electronic device, aiming to solve the problem that the gain of the traditional equalizer circuit cannot be adjusted.

[0005] This application provides an adjustable equalizer circuit, including:

[0006] A cross negative impedance module for compensating the input signal through negative impedance;

[0007] An adjustable current module connected to the cross negative impedance module for providing an adjustable bias current to the cross negative impedance module to adjust the negative impedance generated by the cross negative impedance module through the adjustable bias current.

[0008] In one embodiment, the cross negative impedance module includes a first transistor and a second transistor;

[0009] The first end of the first transistor is used to connect to a first input signal, the second end of the first transistor is connected to the adjustable current module, and the third end of the first transistor is connected to the first end of the second transistor;

[0010] The first end of the second transistor is used to connect to a second input signal, the second end of the second transistor is connected to the adjustable current module, and the third end of the second transistor is connected to the first end of the first transistor.

[0011] In one embodiment, the adjustable current module includes a first adjustable current source;

[0012] The first end of the first adjustable current source is connected to the second end of the first transistor and the second end of the second transistor. The second end of the first adjustable current source is grounded, and the third end of the first adjustable current source is for connection to an external power supply;

[0013] The first adjustable current source is used to provide an adjustable bias current for the first transistor and the second transistor.

[0014] In one embodiment, the adjustable current module includes a second adjustable current source and a third adjustable current source;

[0015] The first end of the second adjustable current source is connected to the second end of the first transistor. The second end of the second adjustable current source is grounded, and the third end of the second adjustable current source is for connection to an external power supply. The second adjustable current source is used to provide an adjustable bias current for the first transistor;

[0016] The first end of the third adjustable current source is connected to the second end of the second transistor. The second end of the third adjustable current source is grounded, and the third end of the third adjustable current source is for connection to the external power supply. The third adjustable current source is used to provide an adjustable bias current for the second transistor.

[0017] In one embodiment, the cross negative impedance module further includes a fixed resistor;

[0018] The first end of the fixed resistor is connected to the second end of the first transistor, and the second end of the fixed resistor is connected to the second end of the second transistor.

[0019] In one embodiment, the cross negative impedance module includes a fixed capacitor;

[0020] The first end of the fixed capacitor is connected to the second end of the first transistor, and the second end of the fixed capacitor is connected to the second end of the second transistor.

[0021] In one embodiment, the cross negative impedance module further includes an adjustable resistor;

[0022] The first end of the adjustable resistor is connected to the second end of the first transistor, and the second end of the adjustable resistor is connected to the second end of the second transistor.

[0023] In one embodiment, the cross negative impedance module further includes an adjustable capacitor;

[0024] The first end of the adjustable capacitor is connected to the second end of the first transistor, and the second end of the adjustable capacitor is connected to the second end of the second transistor.

[0025] The present application provides an adjustable amplifier circuit, including an adjustable equalizer circuit as described in any one of the above embodiments, a pre-amplifier, and a post-amplifier;

[0026] The adjustable equalizer circuit is respectively connected to the output end of the pre-amplifier and the input end of the post-amplifier, and is used to compensate the signal output by the pre-amplifier.

[0027] The present application provides an electronic device, including an adjustable equalizer circuit as described in any one of the above embodiments.

[0028] The beneficial effects of the embodiments of the present utility model compared with the prior art are as follows:

[0029] A negative impedance is generated through the cross negative impedance module, and then an excitation is generated to increase the output amplitude at a certain frequency. The negative impedance generated by the cross negative impedance module can provide additional gain in the high-frequency band to compensate for the attenuation of the channel in the high-frequency part, thereby expanding the bandwidth of the channel. The negative impedance generated by the cross negative impedance module can also help reduce signal distortion and inter-symbol interference, and increase the design flexibility of the CTLE circuit. Therefore, the negative impedance generated by the cross negative impedance module can reduce the influence of load resistance, load capacitance, and parasitic capacitance in the circuit, and can also be understood as compensating for the load resistance, load capacitance, and parasitic capacitance in the circuit, thereby achieving a wider bandwidth and higher high-frequency gain, and thus realizing the compensation of the input signal.

[0030] The adjustable current module and the cross negative impedance module form an adjustable equalizer circuit. The negative impedance generated by the cross negative impedance module in the circuit where the equalizer is located can be expressed as:

[0031] Z N =-2 / g m .

[0032] In the above formula, the negative impedance generated by the cross negative impedance module is the g m function of the two semiconductor amplification devices of the cross-coupling pair. The g m function is a function of the adjustable bias current I S at the tails of the two semiconductor amplification devices, that is By connecting the adjustable current module to the cross negative impedance module, the bias current of the cross negative impedance module can be adjusted, thereby realizing the adjustment of the negative impedance Z N generated by the cross negative impedance module. The negative impedance Z NIt is connected in parallel to the load resistor, load capacitor and parasitic capacitor, and thus can change the zeros and poles in the circuit where it is located, thereby being able to change the frequency response, bandwidth and gain of the circuit. Therefore, through the equalizer adjustable circuit provided by this application, the losses and frequency response characteristics of the circuit can be optimized in terms of bandwidth, gain, peak point and peak amplitude, solving the technical problem that the traditional equalizer circuit cannot adjust the circuit gain, so that the circuit can achieve an equalization effect and compensate and equalize the input signal. Brief Description of the Drawings

[0033] Figure 1 It is a schematic circuit structure diagram of the equalizer adjustable circuit provided by this application;

[0034] Figure 2 It is a schematic circuit structure diagram of the equalizer adjustable circuit in an embodiment provided by this application;

[0035] Figure 3 It is a schematic circuit structure diagram of the equalizer adjustable circuit in an embodiment provided by this application;

[0036] Figure 4 In an embodiment provided by this application Figure 3 The implementation structure of each component in the equalizer adjustable circuit in the application circuit;

[0037] Figure 5 It is a schematic circuit structure diagram of the amplifier adjustable circuit in an embodiment provided by this application;

[0038] Figure 6 It is a schematic circuit structure diagram of the amplifier adjustable circuit in an embodiment provided by this application;

[0039] Figure 7 It is a schematic circuit structure diagram of the amplifier adjustable circuit in an embodiment provided by this application. Detailed Description of the Embodiment

[0040] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clear, the following further details this application in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application.

[0041] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0042] It should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0043] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality of" means two or more unless otherwise specifically defined.

[0044] Please refer to Figure 1 , the present application provides an equalizer adjustable circuit 100. The equalizer adjustable circuit 100 includes a cross negative impedance module 10 and an adjustable current module 20. The cross negative impedance module 10 is used to compensate the input signal through negative impedance. The adjustable current module 20 is connected to the cross negative impedance module 10. The adjustable current module 20 is used to provide an adjustable bias current for the cross negative impedance module 10 to adjust the negative impedance generated by the cross negative impedance module 10 through the adjustable bias current.

[0045] In this embodiment, the cross negative impedance module 10 includes at least two semiconductor amplifying devices, and the connection structure of the two semiconductor amplifying devices is a cross-coupled pair structure. Among them, the semiconductor amplifying device can be a CMOS transistor or a BJT bipolar transistor, etc. A negative impedance is generated through the cross negative impedance module 10, and then an excitation is generated to increase the output amplitude at a certain frequency. The negative impedance generated by the cross negative impedance module 10 can provide additional gain in the high-frequency band to compensate for the attenuation of the channel in the high-frequency part, thereby expanding the bandwidth of the channel. The negative impedance generated by the cross negative impedance module 10 can also help reduce signal distortion and inter-symbol interference and increase the design flexibility of the CTLE circuit. Therefore, the negative impedance generated by the cross negative impedance module 10 can reduce the influence of the load resistance, load capacitance, and parasitic capacitance in the circuit where it is located, and can also be understood as compensating for the load resistance, load capacitance, and parasitic capacitance in the circuit where it is located, thereby achieving a wider bandwidth and higher high-frequency gain, and thus realizing the compensation of the input signal.

[0046] The adjustable current module 20 includes at least one adjustable current source. The adjustable current module 20 and the cross negative impedance module 10 form the equalizer adjustable circuit 100. The negative impedance generated by the cross negative impedance module 10 in the equalizer adjustable circuit 100 can be expressed as:

[0047] Z N = -2 / g m 1.

[0048] In the above formula, the negative impedance generated by the cross negative impedance module 10 is the g of the two semiconductor amplifying devices of the cross-coupled pair m1 function. g m1 represents the transconductance of the transistor. g m1 The function can also be expressed as a function of the adjustable bias current I at the tails of the two semiconductor amplifying devices S1 That is By connecting the adjustable current module 20 to the cross negative impedance module 10, the bias current of the cross negative impedance module 10 can be adjusted, thereby realizing the adjustment of the negative impedance Z generated by the cross negative impedance module 10 N of. The negative impedance Z N is connected in parallel with the load resistor, load capacitor, and parasitic capacitor, and thus can change the zeros and poles in the circuit, thereby being able to change the frequency response, bandwidth, and gain of the circuit. Therefore, through the equalizer adjustable circuit 100 provided by the present application, the loss and frequency response characteristics of the circuit can be optimized in terms of bandwidth, gain, peak point, and peak amplitude, solving the technical problem that the traditional equalizer circuit cannot adjust the circuit gain, so that the circuit can achieve an equalization effect and compensate and equalize the input signal

[0049] In one embodiment, the cross negative impedance module 10 includes a first transistor 110 and a second transistor 120. The first end of the first transistor 110 is used to connect to the first input signal. The second end of the first transistor 110 is connected to the adjustable current module 20. The third end of the first transistor 110 is connected to the first end of the second transistor 120. The first end of the second transistor 120 is used to connect to the second input signal. The second end of the second transistor 120 is connected to the adjustable current module 20. The third end of the second transistor 120 is connected to the first end of the first transistor 110

[0050] In this embodiment, the first transistor 110 and the second transistor 120 are transistors of the same type. The first transistor 110 and the second transistor 120 may both be CMOS transistors. Alternatively, the first transistor 110 and the second transistor 120 may both be BJT bipolar transistors. The third terminal of the first transistor 110 is connected to the first terminal of the second transistor 120, and the third terminal of the second transistor 120 is connected to the first terminal of the first transistor 110, forming a cross-coupled structure. The adjustable current module 20 is respectively connected to the second terminals of the first transistor 110 and the second transistor 120, and can provide adjustable bias currents for the first transistor 110 and the second transistor 120 to adjust the negative impedance generated by the cross negative impedance module 10 through the adjustable bias currents. The first transistor 110, the second transistor 120, and the adjustable current module 20 constitute an equalizer adjustable circuit 100.

[0051] In one embodiment, both the first transistor 110 and the second transistor 120 are NMOS transistors. The first terminal of the first transistor 110 is the drain of the NMOS transistor. The second terminal of the first transistor 110 is the source of the NMOS transistor. The third terminal of the first transistor 110 is the gate of the NMOS transistor. The first terminal of the second transistor 120 is the drain of the NMOS transistor. The second terminal of the second transistor 120 is the source of the NMOS transistor. The third terminal of the second transistor 120 is the gate of the NMOS transistor. The drain of the first transistor 110 is connected to the first input signal. The source of the first transistor 110 is connected to the adjustable current module 20. The gate of the first transistor 110 is connected to the drain of the second transistor 120. The drain of the second transistor 120 is connected to the second input signal. The source of the second transistor 120 is connected to the adjustable current module 20. The gate of the second transistor 120 is connected to the drain of the first transistor 110.

[0052] In one embodiment, the adjustable current module 20 includes a first adjustable current source 210. The first terminal of the first adjustable current source 210 is connected to the second terminals of the first transistor 110 and the second transistor 120. The second terminal of the first adjustable current source 210 is grounded. The third terminal of the first adjustable current source 210 is used to be connected to an external power supply. The first adjustable current source 210 is used to provide adjustable bias currents for the first transistor 110 and the second transistor 120.

[0053] In this embodiment, the first adjustable current source 210 may be an adjustable current source. By providing power to the first adjustable current source 210 through an external power supply Vs, a current with an adjustable magnitude can be output. The first adjustable current source 210, the first transistor 110, and the second transistor 120 form an equalizer adjustable circuit 100. Through the first adjustable current source 210, the adjustable bias currents of the first transistor 110 and the second transistor 120 can be precisely adjusted, and the output current can be maintained stable under different load conditions and environmental changes, meeting the requirements for high-precision current output. Through the first adjustable current source 210, the adjustable bias currents of the first transistor 110 and the second transistor 120 can be precisely adjusted to adjust the negative impedance generated by the first transistor 110 and the second transistor 120 through the adjustable bias currents. The negative impedance is connected in parallel with the load resistor, load capacitor, and parasitic capacitance, and thus the zeros and poles in the circuit can be changed, thereby being able to change the frequency response, bandwidth, and gain of the circuit. Therefore, through the first adjustable current source 210 provided in this application, the losses and frequency response characteristics of the circuit can be optimized in terms of bandwidth, gain, peak point, and peak amplitude, solving the technical problem that the traditional equalizer circuit cannot adjust the circuit gain. Through the first adjustable current source 210 provided in this application, the first input signal and the second input signal can also be compensated and adjusted (for example: amplitude compensation, frequency compensation, and equalization compensation, etc.), so that the circuit can achieve an equalization effect.

[0054] In one embodiment, the equalizer adjustable circuit 100 composed of the first adjustable current source 210, the first transistor 110, and the second transistor 120 is connected in the middle of two-stage CML (Current-Mode Logic) amplifiers for verification and analysis of the equalizer adjustable circuit 100. The adjustable current module 20 is implemented by mirror current. By increasing the adjustable bias current of the cross negative impedance module 10 provided by the adjustable current module 20, the gain of the frequency response in the circuit can be increased, and the bandwidth of the frequency response can be reduced. By reducing the adjustable bias current of the cross negative impedance module 10 provided by the adjustable current module 20, the gain of the frequency response can be reduced, and the bandwidth of the frequency response can be increased. From this, it can be known that through the equalizer adjustable circuit 100 provided in this application, the technical problem that the traditional equalizer circuit cannot adjust the circuit gain can be solved.

[0055] Please refer to Figure 2, in one embodiment, the adjustable current module 20 includes a second adjustable current source 220 and a third adjustable current source 230. The first end of the second adjustable current source 220 is connected to the second end of the first transistor 110. The second end of the second adjustable current source 220 is grounded. The third end of the second adjustable current source 220 is used to connect to an external power supply. The second adjustable current source 220 is used to provide an adjustable bias current for the first transistor 110. The first end of the third adjustable current source 230 is connected to the second end of the second transistor 120. The second end of the third adjustable current source 230 is grounded. The third end of the third adjustable current source 230 is used to connect to an external power supply. The third adjustable current source 230 is used to provide an adjustable bias current for the second transistor 120.

[0056] In this embodiment, the second adjustable current source 220 and the third adjustable current source 230 can be adjustable current sources. By using the external power supply V s to supply power to the second adjustable current source 220 and the third adjustable current source 230, a current with an adjustable magnitude can be output. The second adjustable current source 220, the third adjustable current source 230, the first transistor 110, and the second transistor 120 form an equalizer adjustable circuit 100. By the second adjustable current source 220, the adjustable bias current of the first transistor 110 can be precisely adjusted, and under different load conditions and environmental changes, the output current can be maintained stable, and high-precision current output can be satisfied.

[0057] By the third adjustable current source 230, the adjustable bias current of the second transistor 120 can be precisely adjusted, and under different load conditions and environmental changes, the output current can be maintained stable, and high-precision current output can be satisfied. By the second adjustable current source 220, the adjustable bias current of the first transistor 110 can be precisely adjusted, and by the third adjustable current source 230, the adjustable bias current of the second transistor 120 can be precisely adjusted, so as to adjust the negative impedance generated by the first transistor 110 and the second transistor 120 through the adjustable bias current. The negative impedance of the cross negative impedance module 10 in the equalizer adjustable circuit 100 can be expressed as:

[0058] Z N = -(2 / g m2 ) / / -(2 / g m3 ).

[0059] In the above formula, the negative impedance generated by the cross negative impedance module 10 is the g m2 transconductance function of the first transistor 110 and the second transistor 120 of the cross-coupled pair and the g m3 transconductance function. The g m2 function can also be expressed as a function of the adjustable bias current at the tail of the first transistor 110, that is g m3The function can also be expressed as a function of the adjustable bias current at the tail of the second transistor 120, that is -(2 / g m2 ) represents the negative impedance of the circuit connecting the first transistor 110 and the second adjustable current source 220. -(2 / g m2 ) represents the negative impedance of the circuit connecting the second transistor 120 and the third adjustable current source 230. " / / " represents a parallel relationship. Further, the negative impedance Z N is connected in parallel with the load resistor, load capacitor, and parasitic capacitance, and can change the zeros and poles in the circuit where it is located, thereby being able to change the frequency response, bandwidth, and gain of the circuit. Therefore, through the equalizer adjustable circuit 100 provided by the present application, the losses and frequency response characteristics of the circuit can be optimized in terms of bandwidth, gain, peak point, and peak amplitude, solving the technical problem that the traditional equalizer circuit cannot adjust the circuit gain, so that the circuit can achieve an equalization effect and compensate and equalize the input signal.

[0060] Please refer to Figure 2 , in an embodiment, the cross negative impedance module 10 further includes a fixed resistor 130. The first end of the fixed resistor 130 is connected to the second end of the first transistor 110. The second end of the fixed resistor 130 is connected to the second end of the second transistor 120.

[0061] In this embodiment, the resistance value of the fixed resistor 130 can be set according to the actual application scenario. The first end of the fixed resistor 130 is connected to the second end of the first transistor 110 and is connected to the first end of the second adjustable current source 220. The second end of the fixed resistor 130 is connected to the second end of the second transistor 120 and is connected to the first end of the third adjustable current source 230. The cross-coupled first transistor 110 and second transistor 120, fixed resistor 130, second adjustable current source 220, and third adjustable current source 230 form the equalizer adjustable circuit 100. Through the fixed resistor 130, the negative impedance of the cross negative impedance module 10 can be matched and adjusted, and the influence of the load resistor, load capacitor, and parasitic capacitance in the circuit where it is applied can be reduced.

[0062] Please refer to Figure 2 , in an embodiment, the cross negative impedance module 10 further includes a fixed capacitor 140. The first end of the fixed capacitor 140 is connected to the second end of the first transistor 110. The second end of the fixed capacitor 140 is connected to the second end of the second transistor 120.

[0063] In this embodiment, the capacitance value of the fixed capacitor 140 can be set according to the actual application scenario. The first end of the fixed capacitor 140 is connected to the second end of the first transistor 110 and the first end of the second adjustable current source 220. The second end of the fixed capacitor 140 is connected to the second end of the second transistor 120 and the first end of the third adjustable current source 230. The cross-coupled first transistor 110 and second transistor 120, the fixed resistor 130, the fixed capacitor 140, the second adjustable current source 220, and the third adjustable current source 230 form the equalizer adjustable circuit 100.

[0064] When the C of the first transistor 110 and the second transistor 120 gs is much smaller than C s the negative impedance formed by the negative resistor and negative capacitor in the cross negative impedance module 10 can be expressed as:

[0065] Z N = -(2 / g m2 +R s1 ) / / -(2 / g m3 + 1 / jωC s1 ).

[0066] In the above formula, R s1 is the resistance value of the fixed resistor 130, C s1 is the capacitance value of the fixed capacitor 140, g m2 is the transconductance function of the first transistor 110, which can also be expressed as a function of the adjustable bias current at the tail of the first transistor 110, that is g m3 is the transconductance function of the second transistor 120, which can also be expressed as a function of the adjustable bias current at the tail of the second transistor 120, that is The negative impedance Z N is connected in parallel with the load resistor, load capacitor, and parasitic capacitance, and can change the zeros and poles of the circuit where it is located, thereby enabling the change of the frequency response, bandwidth, and gain of the circuit. Therefore, through the equalizer adjustable circuit 100 provided in this application, the loss and frequency response characteristics of the circuit can be optimized in terms of bandwidth, gain, peak point, and peak amplitude, solving the technical problem that the traditional equalizer circuit cannot adjust the circuit gain, so that the circuit can achieve an equalization effect and compensate and equalize the input signal.

[0067] In one embodiment, an equalizer adjustable circuit 100 composed of a cross-coupled first transistor 110 and second transistor 120, a fixed resistor 130, a fixed capacitor 140, a second adjustable current source 220, and a third adjustable current source 230 is connected in the middle of a two-stage CML amplifier, and the equalizer adjustable circuit 100 is verified and analyzed. By increasing the adjustable bias current values of the second adjustable current source 220 and the third adjustable current source 230, the gain of the frequency response in the circuit can be increased, and the high-frequency peak amplitude of the frequency response can be reduced. By reducing the adjustable bias current values of the second adjustable current source 220 and the third adjustable current source 230, the gain of the frequency response can be reduced, and the high-frequency peak amplitude of the frequency response can be increased. Thus, it can be known that the technical problem that the traditional equalizer circuit cannot adjust the circuit gain can be solved by the equalizer adjustable circuit 100 provided in this application.

[0068] Please refer to Figure 3 , in one embodiment, the cross-negative impedance module 10 further includes an adjustable resistor 150. The first end of the adjustable resistor 150 is connected to the second end of the first transistor 110. The second end of the adjustable resistor 150 is connected to the second end of the second transistor 120.

[0069] In this embodiment, the resistance value of the adjustable resistor 150 can be adjusted according to the actual application scenario, and it has the advantages of flexibility, precise adjustment, convenience in testing and debugging, cost saving, and strong adaptability. The first end of the adjustable resistor 150 is connected to the second end of the first transistor 110 and is also connected to the first end of the second adjustable current source 220. The second end of the adjustable resistor 150 is connected to the second end of the second transistor 120 and is also connected to the first end of the third adjustable current source 230. The cross-coupled first transistor 110, second transistor 120, adjustable resistor 150, second adjustable current source 220, and third adjustable current source 230 form the equalizer adjustable circuit 100. By means of the adjustable resistor 150, the low-frequency gain of the circuit can be changed.

[0070] The adjustable resistor 150, the second adjustable current source 220, and the third adjustable current source 230 form three adjustable parameters of the cross-negative impedance module 10, and can perform flexible impedance matching adjustment on the negative impedance of the cross-negative impedance module 10, can be applicable to different application scenarios, and further reduce the influence of the load resistance, load capacitance, and parasitic capacitance in the application circuit, and can adjust all parameter characteristics such as gain, bandwidth, peak amplitude, and peak frequency point in the circuit.

[0071] Please refer to Figure 3 , in one embodiment, the cross-negative impedance module 10 further includes an adjustable capacitor 160. The first end of the adjustable capacitor 160 is connected to the second end of the first transistor 110. The second end of the adjustable capacitor 160 is connected to the second end of the second transistor 120.

[0072] In this embodiment, the adjustable capacitor 160 can be adjusted according to the actual application scenario, and has the advantages of frequency tuning, compensation function, optimized circuit performance, strong applicability, and space and cost savings. The first end of the adjustable capacitor 160 is connected to the second end of the first transistor 110 and the first end of the second adjustable current source 220. The second end of the adjustable capacitor 160 is connected to the second end of the second transistor 120 and the first end of the third adjustable current source 230. The cross-coupled first transistor 110, second transistor 120, adjustable resistor 150, adjustable capacitor 160, second adjustable current source 220, and third adjustable current source 230 form the equalizer adjustable circuit 100.

[0073] When the C of the first transistor 110 and the second transistor 120 gs is much smaller than C s , the negative impedance composed of the negative resistance and negative capacitance in the cross-negative impedance module 10 can be expressed as:

[0074] Z N = -(2 / g m2 + R s2 ) / / -(2 / g m3 + 1 / jωC s2 ).

[0075] In the above formula, R s2 is the resistance value of the adjustable resistor 150, C s2 is the capacitance value of the adjustable capacitor 160, g m2 is the transconductance function of the first transistor 110, and can also be expressed as a function of the adjustable bias current at the tail of the first transistor 110, that is g m3 is the transconductance function of the second transistor 120, and can also be expressed as a function of the adjustable bias current at the tail of the second transistor 120, that is It can be seen from the formula that the negative impedance Z N in is generated by the parallel connection of g m2 , g m3 , R s2 , and C s2 . By changing the variables of g m2 , g m3 , R s2 , and C s2 , the value of the negative impedance Z N can be changed. The negative impedance Z NConnected in parallel to the load resistor, load capacitor, and parasitic capacitance, it can change the zeros and poles of the circuit where it is located, thereby being able to change the frequency response, bandwidth, and gain of the circuit. Therefore, through the equalizer adjustable circuit 100 provided by the present application, the losses and frequency response characteristics of the circuit can be optimized in terms of bandwidth, gain, peak point, and peak amplitude, solving the technical problem that the traditional equalizer circuit cannot adjust the circuit gain, so that the circuit can achieve an equalization effect and compensate and equalize the input signal.

[0076] In one embodiment, the equalizer adjustable circuit 100 composed of the cross-coupled first transistor 110 and second transistor 120, adjustable resistor 150, adjustable capacitor 160, second adjustable current source 220, and third adjustable current source 230 is connected in the middle of two-stage CML amplifiers for verification and analysis of the equalizer adjustable circuit 100. First, the influence of each variable on the frequency response is examined. By changing the adjustable capacitor 160, the peak value of the frequency response in the circuit where it is located and the frequency point of the peak value can be increased. By changing the adjustable resistor 150, the peak value and the frequency point of the peak value can be changed. By reducing the resistance value of the adjustable resistor 150, the gain of the frequency response can be increased. By increasing the tail current values of the second adjustable current source 220 and the third adjustable current source 230, the gain of the frequency response can be increased, the peak amplitude of the frequency response can be reduced, and the frequency point of the peak value can be changed.

[0077] Secondly, by adjusting the values of the adjustable resistor 150, adjustable capacitor 160, second adjustable current source 220, and third adjustable current source 230, the required bandwidth, gain, peak amplitude, and frequency point of the peak value can be obtained.

[0078] Please refer to Figure 4 , the adjustable capacitor 160 can also be implemented in the application circuit through the component structure shown in (a) of Figure 4 . The adjustable resistor 150 can also be implemented in the application circuit through the component structure shown in (b) of Figure 4 . The first adjustable current source 210, second adjustable current source 220, and third adjustable current source 230 can also be implemented in the application circuit through the component structure shown in (c) of Figure 4 .

[0079] Please refer to Figure 5 , Figure 6 and Figure 7 shown, the present application provides an amplifier adjustable circuit, including the equalizer adjustable circuit 100 of any one of the above embodiments and a pre-stage amplifier 250 and a post-stage amplifier 260. The equalizer adjustable circuit 100 is respectively connected to the output end of the pre-stage amplifier 250 and the input end of the post-stage amplifier 260 for compensating the signal output by the pre-stage amplifier 250.

[0080] In this embodiment, the signal source is connected to the pre - amplifier 250. The pre - amplifier 250 preliminarily amplifies and processes the signal V output by the signal source, and then outputs and connects to the equalizer adjustable circuit 100. The equalizer adjustable circuit 100 equalizes and compensates the signal output by the pre - amplifier 250 (which can be understood as the first input signal and the second input signal mentioned in the above - mentioned embodiment) to improve the signal quality. The signal compensated by the equalizer adjustable circuit 100 is connected to the post - amplifier 260. The post - amplifier 260 amplifies the power of the signal processed by the pre - amplifier 250 and the equalizer adjustable circuit 100, and finally outputs the signal V in .. The first end of the first transistor 110 is connected to the first output end of the pre - amplifier 250 and the first input end of the post - amplifier 260. The first end of the second transistor 120 is connected to the second output end of the pre - amplifier 250 and the second input end of the post - amplifier 260. When both the first transistor 110 and the second transistor 120 are NMOS transistors, the drain of the first transistor 110 is connected to the first output end of the pre - amplifier 250 and the first input end of the post - amplifier 260. The drain of the second transistor 120 is connected to the second output end of the pre - amplifier 250 and the second input end of the post - amplifier 260. out

[0081] The amplifier adjustable circuit further includes a first load resistor 210 (which can also be referred to as R L1 ), a second load resistor 220 (which can also be referred to as R L2 ), a first parasitic capacitor 230 (which can also be referred to as C L1 ), and a second parasitic capacitor 240 (which can also be referred to as C L2 ). The equalizer adjustable circuit 100 is connected to the output ends of the pre - amplifier 250, the first load resistor 210 (which can also be referred to as R L1 ), the second load resistor 220 (which can also be referred to as R L2 ), the first parasitic capacitor 230 (which can also be referred to as C L1 ), and the second parasitic capacitor 240 (which can also be referred to as C L2 ). The first end of the first transistor 110 is also connected to the first end of the first load resistor 210 (which can also be referred to as R L1 ) and the first end where the first parasitic capacitor 230 (which can also be referred to as C L1 ) is connected. The second end of the first load resistor 210 (which can also be referred to as R L1 ) is connected to the second end of the first parasitic capacitor 230 (which can also be referred to as C L1 ). The first end of the second transistor 120 is also connected to the first end of the second load resistor 220 (which can also be referred to as R L2 ) and the first end of the second parasitic capacitor 240 (which can also be referred to as C​L2 ) is connected to the first end. The second load resistor 220 (which can also be referred to as R L2 )'s second end and the second parasitic capacitor 240 (which can also be referred to as C L2 )'s second end are connected.

[0082] By adjusting various parameters in the cross negative impedance module 10 of the equalizer adjustable circuit 100, the zeros and poles of the amplifier adjustable circuit can be changed, thereby being able to change all parameters of the amplifier adjustable circuit, such as gain, bandwidth, amplitude of the peak, and frequency point of the peak, etc.

[0083] This application provides an electronic device, including the equalizer adjustable circuit 100 of any one of the above embodiments. The electronic device can be a receiver or transceiver device in fields such as high-speed serial communication, wireless communication, and audio processing, so as to improve the transmission performance and reliability of signals. The equalizer adjustable circuit 100 can be applied to different nodes on the transmission link. When the equalizer adjustable circuit 100 is applied to the output end of the driving circuit, driving a load with a large load capacitance, it can compensate for the influence of the large load capacitance on the bandwidth and can change the output amplitude. The equalizer adjustable circuit 100 can also adjust the output impedance of the driving circuit to achieve the purpose of impedance matching. When the equalizer adjustable circuit 100 is applied to the input end of the amplifying circuit, it can also compensate for the input transmission line.

[0084] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the above division of each functional unit and module is used as an example. In actual applications, the above functions can be allocated to different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit. In addition, the specific names of each functional unit and module are only for the convenience of mutual distinction and do not limit the protection scope of this application. The specific working process of the units and modules in the above system can refer to the corresponding process in the foregoing method embodiment and will not be elaborated here.

[0085] In the above embodiments, the descriptions of the respective embodiments each have their own emphasis. For parts not described in detail or recorded in a certain embodiment, reference may be made to the relevant descriptions of other embodiments. The division of modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the couplings or direct couplings or communication connections shown or discussed with each other may be through some interfaces. The indirect couplings or communication connections of devices or units may be in electrical, mechanical or other forms.

[0086] In addition, in each embodiment of the present application, the functional units may be integrated in a processing unit, or each unit may exist physically alone, or two or more units may be integrated in one unit. The above integrated units may be implemented in the form of hardware or in the form of software functional units.

[0087] The above-described embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements for some of the technical features. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of each embodiment of the present application and should all be included within the protection scope of the present application.

Claims

1. An adjustable equalizer circuit, characterized in that: include: A cross negative impedance module (10), used for compensating the input signal through negative impedance; An adjustable current module (20) is connected to the cross negative impedance module (10) and is used to provide an adjustable bias current for the cross negative impedance module (10) so as to adjust the negative impedance generated by the cross negative impedance module (10) through the adjustable bias current.

2. The adjustable equalizer circuit according to claim 1, characterized in that: The cross negative impedance module (10) comprises a first transistor (110) and a second transistor (120); The first end of the first transistor (110) is used to be connected to a first input signal, the second end of the first transistor (110) is connected to the adjustable current module (20), and the third end of the first transistor (110) is connected to the first end of the second transistor (120); The first end of the second transistor (120) is used to be connected to a second input signal, the second end of the second transistor (120) is connected to the adjustable current module (20), and the third end of the second transistor (120) is connected to the first end of the first transistor (110).

3. The adjustable equalizer circuit as claimed in claim 2, characterized in that: The adjustable current module (20) comprises a first adjustable current source (210); A first end of the first adjustable current source (210) is connected to a second end of the first transistor (110) and a second end of the second transistor (120), a second end of the first adjustable current source (210) is grounded, and a third end of the first adjustable current source (210) is used to be connected to an external power source; The first adjustable current source (210) is used to provide an adjustable bias current for the first transistor (110) and the second transistor (120).

4. The adjustable equalizer circuit as claimed in claim 2, characterized in that: The adjustable current module (20) comprises a second adjustable current source (220) and a third adjustable current source (230); A first end of the second adjustable current source (220) is connected to a second end of the first transistor (110), a second end of the second adjustable current source (220) is grounded, a third end of the second adjustable current source (220) is used to connect to an external power source, and the second adjustable current source (220) is used to provide an adjustable bias current for the first transistor (110); A first end of the third adjustable current source (230) is connected to a second end of the second transistor (120), a second end of the third adjustable current source (230) is grounded, a third end of the third adjustable current source (230) is used to be connected to the external power source, and the third adjustable current source (230) is used to provide an adjustable bias current for the second transistor (120).

5. The adjustable equalizer circuit as claimed in claim 2, characterized in that: The cross negative impedance module (10) further includes a fixed resistor (130); The first end of the fixed resistor (130) is connected to the second end of the first transistor (110), and the second end of the fixed resistor (130) is connected to the second end of the second transistor (120).

6. The adjustable equalizer circuit as claimed in claim 2, characterized in that: The cross negative impedance module (10) further includes a fixed capacitor (140); The first end of the fixed capacitor (140) is connected to the second end of the first transistor (110), and the second end of the fixed capacitor (140) is connected to the second end of the second transistor (120).

7. The adjustable equalizer circuit as claimed in claim 2, characterized in that: The cross negative impedance module (10) further includes an adjustable resistor (150); The first end of the adjustable resistor (150) is connected to the second end of the first transistor (110), and the second end of the adjustable resistor (150) is connected to the second end of the second transistor (120).

8. The adjustable equalizer circuit as claimed in claim 2, characterized in that: The cross negative impedance module (10) further includes an adjustable capacitor (160); The first end of the adjustable capacitor (160) is connected to the second end of the first transistor (110), and the second end of the adjustable capacitor (160) is connected to the second end of the second transistor (120).

9. An adjustable amplifier circuit, characterized in that: The invention comprises an adjustable equalizer circuit as claimed in any one of claims 1 to 8, and a pre-stage amplifier (250) and a post-stage amplifier (260); The adjustable equalizer circuit is respectively connected to the output end of the pre-stage amplifier (250) and the input end of the post-stage amplifier (260), and is used to compensate for the signal output by the pre-stage amplifier (250).

10. An electronic device, characterized in that: The invention comprises an adjustable equalizer circuit as claimed in any one of claims 1 to 8.

Images