CN111654784A - Direct-selection amplification universal circuit scheme for weak signals in complex signal environment and implementation method - Google Patents

Direct-selection amplification universal circuit scheme for weak signals in complex signal environment and implementation method Download PDF

Info

Publication number
CN111654784A
CN111654784A CN202010370267.5A CN202010370267A CN111654784A CN 111654784 A CN111654784 A CN 111654784A CN 202010370267 A CN202010370267 A CN 202010370267A CN 111654784 A CN111654784 A CN 111654784A
Authority
CN
China
Prior art keywords
signal
circuit
operational amplifier
signals
output
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202010370267.5A
Other languages
Chinese (zh)
Inventor
柏建民
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to CN202010370267.5A priority Critical patent/CN111654784A/en
Publication of CN111654784A publication Critical patent/CN111654784A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers, loudspeakers or microphones
    • H04R3/12—Circuits for transducers, loudspeakers or microphones for distributing signals to two or more loudspeakers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2430/00—Signal processing covered by H04R, not provided for in its groups

Landscapes

  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Amplifiers (AREA)

Abstract

The functional framework of the direct-selection amplification general circuit scheme and the realization method for weak signals in complex signal environments is shown in figure 1. Single-ended input VINThe signals are processed into two paths of same signals by a constant amplitude generating circuit. And respectively obtaining partial amplitude difference signals through asymmetric processing of two independent processing units. The selective amplifying circuit effectively amplifies the amplitude difference signal, other signals are processed only, and the two signals are superposed to output a single-ended signal VOUT. By changing the design of the two signal processing units, a new functional circuit can be obtained. Example (c): single ended signal VINSimultaneously, after passing through two parallel signal follower circuits (formed by directly connecting the negative phase end of a single operational amplifier with an output end) A and B, obtaining signals VA and VB through RC low-pass filter circuits with cut-off frequencies of F1 and F2 respectively; VA is after the signal follower circuit C, through resistance R0 to the Z negative phase terminal of operational amplifier, and then through resistance RZ to the Z output terminal of operational amplifier; this end can obtain single-ended output signal VOUT. VB is connected to the positive phase end of the operational amplifier Z. The signal with the frequency between F1 and F2 is amplified by a factor proportional to RZ/R0.

Description

Direct-selection amplification universal circuit scheme for weak signals in complex signal environment and implementation method
Technical Field
This patent belongs to analog signal processing circuit.
A novel general circuit scheme which can be used for sensor signal processing and can directly select specific signal components for amplification processing of weak signals in a complex signal environment is provided, and an implementation method and a group of example circuits of actual circuit design are provided.
Background
Dilemma of analog circuit
Analog circuit technology can be said to be very difficult to expect relative to the speed of development and the height achieved by digital circuit technology.
Even though the rapid development of consumer electronics and intelligent technologies provides great opportunity for analog circuit technology, analog signal processing technology still fails to get rid of the embarrassment of wandering at low speed.
Whether qualitative or quantitative, analog circuit technology is in urgent need of breakthrough.
Difficulties of analog circuits
There is a class of signals, and the processing requirements of the market are massive and urgent, which is the class of sensor signals.
Sensor signals often have multiple difficulties of complex and changeable signal environment, weak effective signals and high signal processing requirements.
Take electret microphone signal as an example:
● electret microphones are active devices and require a certain bias operating voltage.
● electret microphones typically output audio signals with an amplitude of only a few millivolts.
● the fluctuation range of signal caused by power supply voltage variation, device parameter discreteness, and environmental temperature is often larger than the effective signal itself.
Under the current common rechargeable battery power supply mode, if no special treatment is carried out, the change of the battery power supply range can make the position of the signal center point of the electret microphone signal fluctuate up and down by hundreds of millivolts.
The processing flows of separation and extraction, amplification processing, signal stabilization and the like of the sensor signals bring great difficulty and pressure to corresponding signal processing circuits.
The problems of difficult design, difficult implementation, poor universality, difficult system integration and the like are all puzzling the development of analog circuit technology.
Requirement of analog circuit
With the explosive increase of the number and types of sensors, the analog signal processing technology, especially the effective processing technology of weak signals in complex signal environments, is required to be very urgent and difficult to deal with.
There is a need in the art for a signal processing circuit with good versatility, applicability, and usability, and further for tools and methods for designing such circuits.
In the industry for many years, on the premise that local improvement and improvement effects on the traditional technology are not outstanding, the patent tries to discuss a general circuit scheme with the following characteristics from the ideal requirement:
1. the method has a uniform interface form: single-ended input and single-ended output;
2. the circuits can be used independently, can be stacked in a modularized mode, or can be applied in an embedded mode;
3. the method mainly comprises the following steps of selecting and amplifying specific signal components;
4. the circuit structure has universality;
5. the design of circuit function needs to realize localization, simplification and visualization.
The patent aims at solving the problems of difficult signal separation and extraction, difficult signal amplification condition and environment setting, difficult realization and upgrade adjustment of a feedback circuit design, difficult signal stabilization and the like in a complex signal environment in the traditional signal processing technology,
the following solution ideas are given:
1. in view of the common situation that the environmental signals are complex but the effective signals are relatively simple in the sensor signals, the traditional operation of stripping and rejecting invalid signals is changed into the operation of distinguishing the effective signals, and the signal preprocessing work is simplified.
2. In view of the problems that the traditional amplifying circuit is difficult to establish and maintain and is more difficult to stably operate in a wide working range. The method selects mature circuit technology which can amplify differential mode signals and keep common mode signals passing through, establishes parallel 'amplifying channels' and 'bypass channels', and carries out differentiation processing on signal components, some amplified and some shunted in different signal forms in the same signal.
The main design idea of the present patent can be further given by combining the above two points:
● processing all signal components into common mode signal;
● further processing the signal components to be amplified into differential mode signal form;
● amplifying the differential mode signal by the amplifying circuit, keeping the amplifying characteristic of the common mode signal, realizing the selective amplification of the signal component needing amplifying;
● allow for efficient amplification of particular signal components while allowing for the problem of inherited delivery of unamplified signal components.
The technical scheme and the implementation method for realizing the design idea are provided by the scheme and the implementation method for the direct-selection amplification general circuit for the weak signals in the complex signal environment.
Constant amplitude signal and amplitude difference signal:
in the two-path common ground voltage signal, the part of the two-path signal with equal voltages to ground is generally called a common mode signal, and the part of the two-path signal with different voltages to ground is generally called a differential mode signal.
In order to avoid ambiguity caused by the fact that the direct use of common professional terms may differ from the technical meaning of some specific fields, specific situations and even similar terms in specific applications, in the following related descriptions of the present patent application, a constant amplitude signal is used to express a portion of two signals with the same amplitude as a ground signal, i.e., the common mode signal, and an amplitude difference signal is used to express a portion of two signals with different amplitudes from the ground signal, i.e., a differential mode signal.
The principle scheme is as follows:
1. processing all signal components into a constant amplitude signal;
2. designing a signal processing scheme to further process the signal components needing to be amplified into an amplitude difference signal;
3. the amplifying circuit amplifies the amplitude difference signal and bypasses the amplitude signal.
The technical scheme is as follows:
FIG. 1 is a functional diagram of a general circuit scheme for direct-selection amplification of weak signals in a complex signal environment,
it is composed of three main functional circuit parts:
the constant amplitude signal generating circuit, the amplitude difference signal generating circuit and the signal selective amplifying processing circuit.
Wherein:
● constant amplitude signal generating circuit
The functional characteristics are as follows:
the single-ended voltage-to-ground input signal is processed into two paths of constant amplitude signals with the same signal content and the same signal amplitude, and the two paths of signals are single-ended voltage-to-ground signals.
The circuit is characterized in that:
the parallel signal input unit can be a parallel signal input unit with two input ends connected to a single-ended input signal simultaneously, the functional characteristics of the parallel signal input unit are required to have good input and output characteristics and signal transmission characteristics, and some signal input units can be omitted conditionally;
or a signal input unit is connected to the single-ended input signal, and the other signal copying unit is connected to the output end of the signal input unit;
or can be a pair of signal input modules to realize the output of two paths of same signals;
no matter how various circuit units are connected, the constant amplitude signal generating circuit needs to output the same content and the same signal amplitude, and comprises signal components needing to be amplified and two single-ended voltage-to-ground signals needing to maintain the transmitted signal components.
Inputting connection characteristics:
the input ends are connected with a single-ended voltage-to-ground input signal.
Output connection characteristics:
the two outputs are single-end ground voltage signals and are connected to an amplitude difference signal generating circuit.
● amplitude difference signal generating circuit
The functional characteristics are as follows:
on the basis of the two paths of constant amplitude signals with the same content and the same signal amplitude output by the constant amplitude signal generating circuit, an independent signal processing unit is arranged for each path of signal, and the two signal processing units are total.
And the two signal processing units are used for carrying out asymmetric processing on part of specific signal components, so that the corresponding signal components have signal amplitude difference in the two paths of signals to form corresponding amplitude difference signals.
The circuit is characterized in that:
there are two signal processing units that are independent of each other.
Two paths of signals output by the constant amplitude signal generating circuit are provided with a signal processing unit for each path.
A through-connection can also be regarded as a special form of signal processing unit.
The output of the two signal processing units is a single-ended voltage signal to ground.
Inputting connection characteristics:
and each unit is connected with the output of one path of constant amplitude signal generating circuit.
Output connection characteristics:
two independent signal processing units generate two paths of outputs in the form of single-end voltage-to-ground signals, and the two paths of outputs are connected to the signal selective amplification processing circuit.
● Signal selective amplification processing circuit
The functional characteristics are as follows:
after receiving the two paths of voltage-to-ground signals output by the amplitude difference signal generating circuit, effectively amplifying the part with the signal amplitude difference in the two paths of signals, namely the amplitude difference signal;
meanwhile, the part with equal signal amplitude in the two paths of signals, namely the constant amplitude signal, is kept to pass;
the two are superposed and then output in a single-end voltage-to-ground mode.
The circuit is characterized in that:
the core circuit is a signal selective amplification processing circuit unit with double-end input and single-end output;
two single-end voltage-to-ground signals from the amplitude difference signal generating circuit are respectively connected to two input ends of the signal selective amplification processing circuit unit after passing through respective signal input units which can be omitted under conditions;
the amplitude difference signal part in the two paths of signals is effectively amplified by the signal selective amplification processing circuit unit, the constant-amplitude signal part can keep passing through, and the constant-amplitude signal part are superposed and then output in a single-ended voltage-to-ground signal mode.
Inputting connection characteristics:
the two inputs are connected to the output of the two amplitude difference signal generating circuits.
Output connection characteristics:
the single-ended voltage-to-ground signal is also the output signal of the circuit.
The signal processing flow can be comprehensively described as follows:
as shown in figure 1 of the drawings, in which,
● input signal V in the form of a single-ended voltage-to-ground signalINAfter being processed by a constant-amplitude signal generating circuit consisting of two parallel signal input units or a single signal input processing module, two paths of signals with the same signal content and signal amplitude, namely constant-amplitude signals, are obtained;
● each path of signal will be processed by a signal processing unit, two independent signal processing units form an amplitude difference signal generating circuit, two signal processing units select part of signal components to be amplified to carry out asymmetric processing operation, so that the signal amplitudes of corresponding signal components in the two paths of signals are different to form an amplitude difference signal related to the signal components to be amplified;
● when the two signals reach the signal selective amplification processing circuit, the amplitude difference signal in the two signals, namely the part of the signal amplitude difference, is effectively amplified; the same amplitude signal, namely the part with the same signal amplitude, keeps passing unchanged, the two signals are superposed and then output in the form of a single-ended voltage signal to ground, and the output signal is VOUT。
The implementation method comprises the following steps:
the above technical solutions are applicable to various technical means and methods, such as discrete components, operational amplifiers, circuit units, functional devices, and even system devices, and the like, and are not limited to these technologies.
The design of each part of the circuit can be realized by using a large number of well-known basic circuits, and can be redesigned, such as
● constant amplitude signal generating circuit can be realized by two parallel signal input circuit units, such as signal follower circuit, but not limited to;
the ● amplitude difference signal generating circuit can be implemented by basic circuits that can affect the signal amplitude of some circuit signal components, such as a filter circuit, but not limited to;
the signal amplitude attenuation at one side is a good amplitude difference signal generation means;
the asymmetrical operation of signal amplitude on two sides is a basic technical means for forming amplitude difference signals;
● functional requirements of the signal selective amplifier circuit, many double-ended input amplifier circuits can be satisfied, such as an amplifier circuit with a reference voltage input terminal, but not limited thereto.
The recommendation circuit:
in order to more intuitively explain the characteristics and implementation method of the weak signal direct-selection amplification general circuit scheme in a complex signal environment, a plurality of practical functional circuit design examples are given below.
According to the principle of easy reading and use and abundant resources, a common operational amplifier (hereinafter referred to as operational amplifier) technology is adopted to realize a specific circuit, but the relevant technical features of the patent are not limited to the technology.
All the operational amplifiers are powered by a single power supply, and the processed signals are in the range of application of the power supply and the device characteristics.
Fig. 2 is a proposed development general-purpose basic reference circuit, which provides a proposed circuit for the constant amplitude signal generation circuit and the signal selective amplification processing circuit in the circuit scheme shown in fig. 1, and the two parts of the circuit have certain universality for the design of various functional circuits.
Fig. 2 reserves the positions of two signal processing units, and application circuits with various signal amplification processing functions can be realized through further design of the reserved signal processing units a and B.
Two well-known circuit units were used in developing a universal base reference circuit:
● Single-op-amp signal follower circuit, including signal follower circuits A1, A2 and A3.
The single operational amplifier signal following circuit is formed by short-circuiting an operational amplifier negative phase input end and an output end, and has good input impedance, signal transmission performance and output load driving capacity.
● operational amplifier AZ and resistor R0, RZConstituting a circuit unit.
Double-ended input single-ended output.
■ one input VA is connected to resistor R0, R0, negative phase input of operational amplifier AZ, and resistor RZIs connected to the output of the operational amplifier AZ.
■ is connected to the non-inverting input of the operational amplifier AZ at its other input VB.
The output end of the ■ operational amplifier AZ is the circuit output end.
According to a common approximate analysis method of an operational amplifier circuit, when the operational amplifier circuit is balanced, the two input ends have equal potential, and the input current of the two input ends is zero, so that the currents on the electric groups R0 and RZ are equal, namely:
V+＝V-；
(V--VA)/R0＝(VOUT-V-)/Rz
the signal relation of the amplifying circuit can be obtained as follows:
VOUT＝V-+(Rz/R0)*(V--VA)
changing VB to V-Substituting the relationship of (a) into the expression, can obtain:
VOUT＝VB-(Rz/R0)*(VA-VB)
if VA is expressed as:
VA＝VB+(VA-VB)
comparing the original input signal VA with the output signal VOUTIn between, the common mode signal part, i.e. the on-amplitude signal part VB, is not changed, but the differential mode signal part, i.e. the amplitude-difference signal part (VA-VB), the signal amplitude is amplified in antiphase by a factor of (Rz/R0).
Operational amplifier AZ and resistor R0, RZThe circuit amplification unit is formed to meet the amplification characteristic requirement of the signal selective amplification circuit.
In the development universal base reference circuit shown in figure 2,
● constant amplitude signal generating circuit is composed of signal follower circuits A1 and A2, and the input end is connected to single-end voltage-to-ground signal VIN. The constant-amplitude signal generating circuit provides two paths of same signals and good signal drive for subsequent circuits, namely the reserved signal processing units A and B, and lays a crucial foundation for further symmetry and asymmetry processing of weak signals.
The ● amplitude difference signal generating circuit is composed of two independent reserved signal processing units A and B, and each reserved signal processing unit is responsible for processing an output signal of one path of constant amplitude signal generating circuit.
The two reserved signal processing units respectively select the signal amplitude of part of the signal components in the passing signal components to process, and the combination of the processing conditions possibly suffered by various signal components in the two paths of signals is as follows:
■ case one: some signal component reserved signal processing units A and B are not processed, the amplitudes of two paths of signals of related signal components are not changed and are kept equal continuously, namely the two paths of signals become equal-amplitude signal components.
■ case two: some signal component reserved signal processing units A and B perform symmetrical same processing on the signal components, and the amplitudes of two paths of signals of related signal components are changed identically and still can be equal or basically equal, namely, the two paths of signals become quasi-constant amplitude signals mainly comprising constant amplitude signal components.
■ case three: some signal component reservation signal processing units A and B carry out asymmetric processing on the signals, including the processing of only one-way reservation signal processing unit, or two-way reservation signal processing units A and B carry out different signal processing operations, and the two-way signal amplitude of related signal components can be changed differently, so that the signal amplitude of the related signal components between two-way signals can be different, namely, amplitude difference signal components can be generated, and the signal components can become amplified signal components.
The ● signal selective amplifier circuit comprises an operational amplifier AZ and a resistor R0, RZThe signal selective amplification processing unit is added with a signal follower circuit arranged before a resistor R0A 3.
After receiving the two signals transmitted by the amplitude difference signal generating circuit, the transient voltage signals of the two signals pass through the part with the same signal amplitude, and the part with the signal amplitude difference is amplified in opposite phase (Rz/R0) times, and then the two signals are superposed and output in the form of a single-end voltage-to-ground voltage signal.
The general basic reference circuit for development shown in fig. 2 can realize the design of the corresponding signal processing function circuit by only continuously completing the design of two reserved signal processing units.
Example of application circuit design one: band-pass amplifying circuit
The general basic reference circuit for development shown in fig. 2 is further designed deeply, and two RC low-pass filter circuits are used to replace two reserved signal processing units, so that the band-pass amplifying circuit shown in fig. 3 can be obtained.
In the band-pass amplifying circuit shown in figure 3,
the ● constant amplitude signal generating circuit formed by the signal follower circuits a1 and a2 has been described above.
● operational amplifier AZ, and resistor R0, RZThe signal selective amplifying circuit composed of the signal selective amplifying processing unit and the signal follower circuit a3 has been described above.
● replace the two reserved signal processing units in the circuit of fig. 2 with two RC low pass filter circuits.
The resistor R1 and the capacitor C1 form a low-pass filter circuit R1C1, which replaces the reserved signal processing unit A in FIG. 2;
the resistor R2 and the capacitor C2 form a low-pass filter circuit R2C2 instead of the reserved signal processing unit B in fig. 2.
Analysing the original input signal VINAll signal components in the signal form the case of an amplitude difference signal.
The cutoff frequency of the low-pass filter circuit R1C1 is denoted as F1, and the cutoff frequency of the low-pass filter circuit R2C2 is denoted as F2.
● when the signal frequency of the signal component is lower than F1 and lower than F2, the low pass filter circuits R1C1 and R2C2 are both in the conducting state, the corresponding signal components in the two paths of signals reaching the signal selective amplification processing circuit are both the amplitude of the conducting signal, so as to form quasi-constant amplitude signals, and the existing amplitude difference signals have small amplitude.
● when the signal frequency of the signal component is higher than F1 and also higher than F2, the low pass filter circuits R1C1 and R2C2 are both in cut-off state, and the corresponding signal components in the two paths of signals reaching the signal selective amplification processing circuit are both the amplitude of the cut-off signal, so as to form quasi-constant amplitude signals, and the existing amplitude difference signals have small amplitude.
● when the signal frequency of the signal component is between F1 and F2, one of the low pass filter circuits R1C1 and R2C2 is in the on state, and the other is in the off state, the difference of the signal amplitude of the corresponding signal component in the two signals reaching the signal selective amplifying processing circuit is equal to the difference of the amplitude of the off signal and the on signal.
That is, the effective signal amplitude of the signal component with the signal frequency between F1 and F2 is mostly processed into an amplitude difference signal, and all or most of the effective signal amplitudes of the other signal components are processed into a constant amplitude signal.
● the amplitude difference signal part will be amplified prominently after passing through the amplifying circuit composed of operational amplifier AZ and resistors R0, RZ.
The signal processing result of the circuit of fig. 3 is to effectively amplify the signal with the signal frequency between the cut-off frequencies of the two low-pass filter circuits, and the other signals are kept passing or inhibited to be amplified.
Fig. 3 is a bandpass amplifying circuit.
The upper and lower cut-off frequencies of the band-pass are the cut-off frequencies of the two low-pass filter circuits, the higher frequency is the upper cut-off frequency, and the lower frequency is the lower limit mechanism frequency;
the signal amplification is proportional to (Rz/R0).
Example two of the application circuit design: AC (high-pass) amplifying circuit
Fig. 4 shows an ac (high-pass) amplifier circuit.
Specifically, the following are mentioned: the circuit adopts the overall scheme provided by the patent, and a plurality of parts which can be deleted are greatly deleted.
The electret microphone signal amplifier is mainly designed aiming at specific signals such as electret microphone signals, a signal source is an active signal, the frequency characteristic of the signal is guaranteed not to change along with the change of a load, the influence of the signal amplitude is guaranteed, and the frequency characteristic is adjusted by the amplification factor.
The circuit design is primarily directed to the cost-sensitive and circuit complexity-sensitive consumer market.
As shown in fig. 4
● Single-ended ground-to-ground voltage input signal VINIs connected to a resistor R0 as a signal VA, is connected to the negative phase input end of the operational amplifier AZ through a resistor R0 and then is connected to the negative phase input end of the operational amplifier AZ through a resistor RZConnected to the output of the operational amplifier RZ.
● Single-ended ground-to-ground voltage input signal VINAfter passing through the signal follower circuit A1, the signal follower circuit A1 is connected to the non-inverting input terminal of the operational amplifier AZ through the resistor R1 and then grounded through the C1.
● when the resistors R1 and C1 form an integration circuit, the voltage at the center of the signal, denoted as V, can be obtainedCenter of a shipThat is to say that the input signal VB of the amplifier circuit is the signal center point voltage VCenter of a ship。
According to the amplification relation of the foregoing amplification circuit:
changing VB to VCenter of a ship。
Input signal VINEqual to the sum of the DC component of the signal and the AC signal, i.e.
VA＝VCenter of a ship+VExchange of electricity。
Substitution into
VOUT＝VB-(Rz/R0)*(VA-VB)
It is possible to obtain:
VOUT＝Vcenter of a ship-(Rz/R0)*VExchange of electricity
That is, in the ac (high-pass) amplifier circuit shown in fig. 4, if the resistor R1 and the capacitor C1 form an integrating circuit, the signal amplitude of the ac signal component can be amplified in reverse phase (Rz/R0) while the signal center point is kept substantially constant.
When the values of the resistor R1 and the capacitor C1 form a low-pass circuit R1C1 with the cut-off frequency of F1:
● the frequency of the signal is lower than that of the signal component F1, so quasi-constant amplitude signal is formed between the conducting signal of the low-pass circuit R1C1 and the original signal.
● the signal has a higher frequency than the signal component of F1, the cut-off signal of the low-pass circuit R1C1 forms a significant amplitude difference signal with the original signal.
● at this time, the signal component having a signal frequency higher than F1 will be effectively amplified, and the amplification effect of the other signal components will be suppressed.
The circuit shown in fig. 4 is a high-pass amplifier circuit with a cutoff frequency of F1 when a resistor R1 and a capacitor C1 form a low-pass filter circuit with a cutoff frequency of F1.
The circuit shown in fig. 4 may be an ac signal amplifier circuit or a high-pass amplifier circuit, and is determined by the value ranges of the resistor R1 and the capacitor C1.
The circuit of fig. 4 can be regarded as low-cost electret microphone signal amplifier, if there is the signal stability requirement, can directly connect the signal center point tracking migration locking circuit that this patent fig. 5 provided and realize.
Example three of the application circuit design: signal center point tracking migration locking circuit
FIG. 5 shows a signal center point tracking transition locking circuit.
The circuit does not change the amplitude of the signal, but only shifts and locks the signal center point at a certain reference voltage position.
As shown in fig. 5
● Single-ended ground-to-ground voltage input signal VINIs connected to a resistor R0 as a signal VA, is connected to the negative phase input end of the operational amplifier AZ through a resistor R0 and then is connected to the negative phase input end of the operational amplifier AZ through a resistor RZConnected to the output of the operational amplifier RZ. Resistance R0 and resistance R hereZThe same resistance value is taken.
● Single-ended ground-to-ground voltage input signal VINAfter passing through a signal follower circuit A1, the signal follower circuit is connected to an integrating circuit R1C1 to obtain VINVoltage V at center point of signalCenter of a ship. Connected to a resistor R4 via a signal follower circuit A3 to be connected to a reference voltage VREFAnd carrying out partial pressure operation.
● the power voltage is divided by two resistors R2 and R3 to obtain the reference voltage VREF，VREFOr can be directly arranged from the outside, VREFAfter passing through the signal follower circuit A2, the signal follower circuit A is connected to a resistor R5;
● center point voltage VCenter of a shipAnd a reference voltage VREFThe voltage is divided by two equivalent resistors R4 and R5 to obtain a signal (V)Center of a ship+VREF) The/2 is connected to the positive phase input end of the operational amplifier AZ of the amplifying circuit;
one path of signal VA is represented as: VA is VCenter of a ship+VExchange of electricity。
The other signal VB is represented as: VB ═ VCenter of a ship+VREF)/2。
Substituting into the signal relation formula of the amplifying circuit:
VOUT＝VB-(Rz/R0)*(VA-VB)
it is possible to obtain:
VOUT＝VREF-Vexchange of electricity
Comparing input signals
VIN＝VA＝VCenter of a ship+VExchange of electricity。
It can be found that the shift of the center point of the AC signal is locked at VREFa.C. signal component VExchange of electricityThe amplitude is unchanged but inverted.
The signal center point tracking migration locking circuit shown in fig. 5 can be directly connected with the circuit shown in fig. 3 or fig. 4, so that the position of the amplified signal center point is locked to VREFWhen the resistance values of the resistor R2 and the resistor R3 are equal,
VREF＝(1/2)*VCC。
that is, the signal center point tracking transition locking circuit shown in fig. 5 can lock the position of the center point of the input signal to one-half of the power supply voltage, which is the signal center point setting position required by many conventional amplifying circuits.
Other application circuit design techniques
With the development-use general-purpose basic reference circuit of fig. 2, it is possible to design a variety of functional circuits by flexible design and operational combination of two reserved signal processing units.
For example:
● various functional circuits are constructed by additional signal circuits or some signal generating circuits such as modulation signals, comparison signals, latch signals, slice signals, etc.
● the particular signal generator circuit may be implemented using a combination of various signal sources.
● and other circuit processing methods capable of forming a predictable result between two signals.
Disclosure of Invention
Fig. 1 is a functional block diagram of a general circuit scheme and an implementation method for direct selection and amplification of weak signals in a complex signal environment.
The circuit consists of three functional circuits: the constant amplitude signal generating circuit, the amplitude difference signal generating circuit and the signal selective amplification processing circuit.
Wherein:
● constant amplitude signal generating circuit:
the device consists of two parallel signal input units which can be omitted conditionally, and can also be combined into a signal input module;
the functional characteristics are as follows: processing the single-ended input signal into two paths of signals with the same signal content and the same signal amplitude; the content of the signal is the same or closely related to the input signal.
Input connection: single ended input signal VINThe input ends of two signal input units or the input ends of the signal input modules are connected simultaneously:
and (3) output connection: two paths of signals with the same content, namely constant amplitude signals, are generated and are connected with an amplitude difference signal generating circuit.
● amplitude difference signal generating circuit:
the direct connection is also in a special signal processing unit form;
the functional characteristics are as follows: respectively carrying out asymmetric operation on specific signal components of the two paths of input constant-amplitude signals through the two signal processing units, and generating amplitude difference signals corresponding to the signal components in the two paths of signals output by the two signal processing units;
input connection: two paths of signals from the constant amplitude signal generating circuit, wherein each path of signal is respectively connected to the input end of a signal processing unit;
and (3) output connection: the two signal processing units output two paths of signals and are connected to the signal selective amplification processing circuit.
● Signal selective amplification processing circuit:
selecting or designing double-end input and single-end output, wherein the amplification functional characteristic meets the requirement of effectively amplifying an amplitude difference signal, a circuit unit for passing the amplitude difference signal is kept, and a signal input unit is additionally arranged at an input end if necessary;
the functional characteristics are as follows: effectively amplifying a part with signal amplitude difference between two input signals, namely an amplitude difference signal part, and outputting a part with the same amplitude and a part with the same amplitude in a single-ended signal form after the part with the same amplitude and the part are superposed;
input connection: two paths of signals from the amplitude difference signal generating circuit, and a signal input unit is arranged at an input end if necessary;
and (3) outputting: and outputting in the form of a single-ended voltage-to-ground signal.
The signal processing flow comprises the following steps:
● after a single-end voltage-to-ground input signal VIN is processed by a constant amplitude signal generating circuit, two paths of signals with the same content and amplitude are formed, each path is processed by a signal processing unit independently, and the two signal processing units A and B are total.
● the two signal processing units A, B form an amplitude difference signal generating circuit, and the two signal processing units A, B make the amplitudes of the corresponding signals in the outputs of the two signal processing units A, B generate difference by performing asymmetric processing on the signal amplitudes of partial signal components.
● signal selective amplification processing circuit amplifies the instantaneous voltage amplitude difference part of the two received signals effectively; the parts with the same instantaneous voltage amplitude of the two paths of signals are not amplified and pass through; the two are superposed and output in the form of single-end voltage to ground.
The circuit implementation method comprises the following steps:
● constant amplitude signal generating circuit
Circuits that are capable of generating two identical signals and that contain the signal components required for amplification and transmission are suitable.
For example, the method is realized by adopting two parallel signal input units, wherein the input ends of the two parallel signal input units are connected with input signals and are both single-ended input and single-ended output; or the signal input unit is adopted and then the signal copying unit is adopted to realize the operation; the method can also be realized in a signal distribution mode; the method is not limited thereto.
● amplitude difference signal generating circuit
The two-path signal processing unit circuit can be realized by selecting or redesigning the relevant circuit unit, and the through connection can also be regarded as a special signal processing unit.
How to select and process the signals and how to match between the two signal processing units requires design.
The technical method of outputting two paths of differential mode signals comprising amplified signal components is applicable.
The signal component, which is processed into an amplitude difference signal, will be amplified.
● Signal selective amplification processing circuit
This can be achieved by selecting or designing a corresponding circuit unit that satisfies the requirements of the amplification characteristics.
The input terminal is provided with a signal input unit as necessary to avoid mutual influence between adjacent circuit units, device parameters and signal characteristics.
In order to better illustrate the scheme of the general circuit for direct selection and amplification of weak signals in a complex signal environment and part of the method and the skill in the circuit implementation in the implementation method in fig. 1, the present specification further describes how to build a general basic circuit for development and how to design some common functional circuits, and provides several practical circuits.
The proposed development uses a generic basic circuit:
for convenience of illustration and understanding, a number of circuit implementation examples in this specification have been illustrated using operational amplifiers and circuit elements thereof, but this should not unduly limit the main technical features of this patent.
Meanwhile, it is needless to say that all signals processed by the circuits are within the power supply range of the operational amplifier and the performance support range of the device.
All operational amplifiers are supplied by a single power supply and are sometimes referred to as operational amplifiers for short.
Fig. 2 shows a schematic circuit of a universal basic reference circuit for development:
in the circuit shown in fig. 2, two well-known circuit units are used, and two design positions of the signal processing unit are reserved:
● single-operational-amplifier signal follower circuit
In fig. 2, the operational amplifiers a1, a2 and A3 respectively form signal follower circuits a1, a2 and A3.
Each signal follower circuit is formed by directly connecting the negative phase input end and the output end of the operational amplifier.
The positive phase input end of the operational amplifier is the input end of the signal following circuit, and the output end of the operational amplifier is the output end of the signal following circuit.
The single operational amplifier signal following circuit has high input impedance, good signal transmission performance and strong output load driving capability.
● Signal Selective amplification Unit
In FIG. 2, the operational amplifier AZ and the resistor R0, the resistor RZConstitute a signal selective amplification processing unit.
The signal selective amplification processing unit is in a double-end input single-end output interface form.
Wherein, an input signal at one end is connected to a resistor R0 as VA, is connected to the negative phase input end of the operational amplifier AZ through a resistor R0 and then is connected to the negative phase input end of the operational amplifier AZ through a resistor RZIs connected to the output of the operational amplifier AZ.
And the other end of the input signal VB is connected to the non-inverting input end of the operational amplifier AZ.
The output end of the operational amplifier AZ is the output end of the signal selective amplification unit, and the output signal is a single-ended pairGround voltage signal VOUT。
The signal relation of the signal selective amplification unit is as follows:
VOUT＝VB-(Rz/R0)*(VA-VB)
● in the circuit shown in fig. 2, two signal processing units are also reserved for the design positions.
The signal processing flow of the circuit shown in fig. 2 is as follows:
● Single-ended input Signal VINWhile being connected to the inputs of the signal follower circuits A1, A2, the outputs of the follower circuits A1, A2 will simultaneously obtain the input signal VINThe same signal;
● reservation signal processing circuit A, B input end signal and input signal VINThe same;
the output of the reserved signal processing circuit a reaches the VA input signal position of the amplifying circuit unit after passing through the signal follower circuit a 3.
The output of the reserved signal processing circuit B reaches the VB input signal position of the amplifying circuit unit.
The signal follower circuit a3 is arranged to make the output end of the reserved signal processing unit a directly connected to the input end of the operational amplifier, and the output load environment is symmetrical to the reserved signal processing unit B.
● according to the signal amplification relation of the signal selective amplification processing circuit:
VOUT＝VB-(Rz/R0)*(VA-VB)
shows that:
■, if the reserved signal processing units a, B do not generate a new amplitude difference signal component, (VA-VB) is 0;
VOUT＝VB
■ if the signal processing circuits A and B are reserved and new amplitude difference signal components are generated, then (VA-VB) < > 0
VOUT＝VB-(Rz/R0)*(VA-VB)
From the above analysis, it can be seen that a functional circuit for amplifying a corresponding signal can be designed as long as an amplitude difference signal of some signal components is generated by the matching design of the reserved signal processing units a and B.
The combination of the two reserved signal processing units a, B processing different signal components is:
●, reserving signal components which are not processed by the signal processing units at two sides, keeping the two paths of signals the same, representing the corresponding signal components as constant amplitude signals, and not amplifying the corresponding signal components;
● only one side signal processing unit changes signal amplitude for some signal components to obtain corresponding amplitude difference signal;
●, the signal processing units on both sides carry out the symmetry operation of changing the signal amplitude for some signal components, and corresponding quasi-constant amplitude signals are obtained;
●, the signal processing units on both sides carry out asymmetric operation of changing signal amplitude on certain signal components, and corresponding amplitude difference signals are obtained;
the amplitude difference signal part is effectively amplified, and the constant amplitude signal part is not amplified and is kept to pass through.
On the basis of the development general basic reference circuit shown in fig. 2, a functional circuit for amplifying a specific signal component can be obtained by further designing the two reserved signal processing units a and B.
On the basis, a set of implementation example circuits which are further designed and completed are given:
the device comprises a band-pass amplifying circuit, a high-pass (alternating current) amplifying circuit and a signal center point tracking and shifting locking circuit.
Circuit one of the implementation example: band-pass amplifying circuit
Fig. 3 shows a schematic diagram of a circuit band-pass amplifying circuit according to an embodiment, and comparing fig. 2 shows that:
an RC low-pass filter circuit R1C1 formed by a resistor R1 and a capacitor C1 replaces the reserved signal processing unit A;
an RC low-pass filter circuit R2C2 formed by a resistor R2 and a capacitor C2 replaces the reserved signal processing unit B;
the cutoff frequency of the low-pass filter R1C1 is denoted as F1, and the cutoff frequency of the low-pass filter circuit R2C2 is denoted as F2.
In the bandpass amplifying circuit shown in figure 3,
● Single-ended ground-to-ground voltage input signal VINAfter passing through signal follower circuits A1 and A2 composed of operational amplifiers A1 and A2, the signals respectively reach the input ends of low-pass filter circuits R1C1 and R2C2, and the signals are all equal to VINThe same is true.
● the output signal of the low-pass filter circuit R1C1 reaches VA of the signal selective amplification processing circuit after passing through the follower circuit A3; the output signal of the low-pass filter circuit R2C2 directly reaches VB of the signal selective amplification processing circuit, i.e. the non-inverting input terminal of the power amplifier AZ.
The arrangement of the follower circuit a3 can have two roles:
■ isolating the cross influence of the component parameters between the low-pass filter circuit R1C1 and the signal selective amplification processing unit;
■ the output of the low pass filter circuit R1C1 is connected to the input of the operational amplifier, which is loaded the same as the output of the low pass filter circuit R2C 2.
● VA is input signal VINThe result of the low-pass filter circuit R1C1 is the input signal V at VBINThe result after being processed by a low-pass filter circuit R2C 2;
● the processing results of the two low-pass filters R1C1 and R2C2 for the input signals of different frequency ranges are:
■ when the signal frequency is lower than F1 and the signal frequency is lower than F2, the outputs of the two low-pass filter circuits are both conducting signals, the difference amplitude is small, and the signals are quasi-constant amplitude signals.
■ when the signal frequency is higher than F1 and the signal frequency is higher than F2, the output of the two low-pass filter circuits are both cut-off signals, the phase difference amplitude is small, and the signals are quasi-constant amplitude signals.
■ when the frequency of the signal is between F1 and F2, one of the two low-pass filter circuits is in the cut-off state, the other is in the conducting state, the amplitude difference between the two signals is large, and the amplitude difference signal almost similar to the input signal can be obtained.
● is processed by the signal selective amplifying circuit, according to the signal amplifying relation:
VOUT＝VB-(Rz/R0)*(VA-VB)
it can be known that the signal processing characteristics of the bandpass amplifying circuit of fig. 3 are:
the signal amplitude of the signal with the signal frequency between F1 and F2 is effectively amplified by the sum of (R)Z/R0).
Circuit two of the implementation example: high-pass (AC) amplifying circuit
Fig. 4 shows a schematic diagram of a high-pass (ac) amplifier circuit of an embodiment.
The circuit of fig. 4 can be said to be a typical example of the pursuit of circuit simplification, and can be directly used for simple processing of the electret microphone signal.
The circuit comprises a capacitor C1, two operational amplifiers A1, AZ, and three resistors R1, R0, RZComposition is carried out;
the core circuit is an operational amplifier AZ, a resistor R0 and a resistor RZThe performance characteristics of the formed signal selective amplification processing unit are as described above.
Single end to ground voltage input signal VINOne signal VA directly serving as the signal selective amplification processing unit is connected to the resistor R0.
Simultaneous input signal VINThe signal follower circuit a1 formed by the operational amplifier a1 is connected to a signal VB of the selective amplification processing unit, that is, the non-inverting input terminal of the operational amplifier AZ, through the low-pass filter unit R1C1 (or the integrating circuit R1C1, depending on the values of the resistor R1 and the capacitor C1).
Assume that the cutoff frequency of the low-pass filter unit R1C1 composed of the resistor R1 and the capacitor C1 is F1.
● when the frequency of the input signal is lower than F1, the amplitude of the amplitude difference signal received by the selective amplification processing unit VA, VB is the amplitude difference between the original signal and the conducting signal of the filter circuit, and is small and can be regarded as a quasi-constant amplitude signal.
● when the frequency of the input signal is higher than F1, the amplitude of the amplitude difference signal received at the selective amplifying circuit unit VA, VB is the amplitude difference between the original signal and the cut-off signal of the filter circuit, and can be regarded as the amplitude difference signal.
According to the signal amplification relation of the signal selective amplification processing unit obtained by the analysis, the following steps are carried out:
VOUT＝VB-(Rz/R0)*(VA-VB)
the signal processing characteristics of the high-pass amplification circuit of fig. 4 can be known as follows:
the signal with the frequency higher than F1 is effectively amplified by the sum of the amplification factor and (R)Z/R0).
The circuit now behaves as a high-pass amplification circuit.
When the resistor R1 and the capacitor C1 form an integral circuit by selecting values, the output can be approximately regarded as the voltage of the signal center point, namely
VB＝VCenter of a ship。
If the signal VA is expressed as: VA is VCenter of a ship+VExchange of electricity. Substituting the correlation equation can obtain:
VOUT＝Vcenter of a ship-(Rz/R0)*VExchange of electricity
Under the condition that the central point of the signal is unchanged, the alternating current signal component is effectively amplified, and the amplification ratio is equal to (R)Z/R0).
At this time, the circuit shown in fig. 4 behaves as an ac signal amplifying circuit.
Circuit three of the implementation example: signal center point tracking migration locking circuit
FIG. 5 shows a signal center point tracking transition locking circuit.
The core circuit is an operational amplifier AZ, a resistor R0 and a resistor RZThe signal selective amplification processing unit is analyzed and introduced.
Single end to ground voltage input signal VINOne signal VA directly serving as the signal selective amplification processing unit is connected to the resistor R0.
The signal VA is expressed as: VA is VCenter of a ship+VExchange of electricity。
At this time, VCenter of a shipIs varied with the variation of the center point of the input signal, there may be many influencing factors that cause VCenter of a shipIs fluctuating.
Input signal VINThe signal follower circuit A1 is connected to the integrator circuit R1C1 to obtain the signal center point voltage V of the input signalCenter of a ship. Then the voltage is connected to a resistor R4, namely a VC position after passing through a signal following circuit A3, and the signal at the VC position is VCenter of a ship。
The circuit of FIG. 5 uses resistor R2 and resistor R3 to obtain a reference voltage V for power supply voltage divisionREF，VREFOr can be input from outside the circuit, VREFThe signal is transmitted to a resistor R5, namely VD, through a following circuit A2, and the signal at VD is VREF。
The resistor R4 and the resistor R5 have the same resistance value for V at VCCenter of a shipAnd V at VDREFVoltage division operation is carried out, and a voltage division signal (V) is obtained at the connection part of the resistors R4 and R5Center of a ship+VREF)/2。
Dividing the voltage signals (V) of the resistors R4 and R5Center of a ship+VREF) And/2 is connected to a signal VB of the selective amplification processing unit, namely the non-inverting input end of the operational amplifier AZ.
In this case, VB is (V)Center of a ship+VREF)/2
And VA is equal to VCenter of a ship+VExchange of electricitySignal relation expression substituted into signal selective amplification processing unit together
VOUT＝VB-(Rz/R0)*(VA-VB)
Obtaining: vOUT＝(VCenter of a ship+VREF)/2-(Rz/R0)*((VCenter of a ship+VExchange of electricity)-(VCenter of a ship+VREF)/2)
When the resistance R isZWhen the resistance R0 has the same resistance value, (Rz/R0) is 1, the result is obtained:
VOUT＝VREF-Vexchange of electricity
This means that the signal center point of the alternating signal component in the output signal has been shifted from V, which floats with the original input signalCenter of a shipMigrate to a fixed VREF. The alternating signal component is inverted.
The circuit shown in fig. 5 has a further feature:
except that the resistor R1 needs to be independently valued to obtain better integration circuit characteristics by matching with the capacitor C1, if all other resistors take the same value, the circuit can lock the signal center point to the position of one half of the power supply voltage.
Fig. 5 is a circuit for tracking and shifting a signal center point, which can be directly connected to the amplifying circuits shown in fig. 3 and fig. 4, respectively, to stabilize the signal center point.
Thereby, a large number of processing operations for signal stabilization, operating point stabilization and signal zero point stabilization can be omitted.
Description of the drawings:
the specification has a total of 8 figures, wherein:
fig. 1 is a schematic functional block diagram of a general circuit scheme for direct-selection amplification of weak signals in a complex signal environment and an implementation method.
FIG. 2 is a functional schematic diagram of a general basic circuit for development including a portion of the proposed circuit cells.
Fig. 3 is a schematic diagram of a bandpass amplifying circuit.
Fig. 4 is a schematic diagram of a high-pass (ac) amplifier circuit.
FIG. 5 is a schematic diagram of a signal center point tracking migration locking circuit
Fig. 6 is a circuit diagram of an example implementation of a bandpass amplifying circuit.
Fig. 7 is a circuit diagram of an embodiment of a high-pass amplifying circuit.
FIG. 8 is a circuit diagram of an exemplary embodiment of a signal center point tracking shift locking circuit
Examples
The operational amplifiers used by the following circuits are all general operational amplifiers powered by a single power supply, so that specific models are not specified to avoid misleading.
1. Band pass amplification circuit example
Figure 6 is a circuit diagram of an instantiation of the parameters of the bandpass amplification circuit of figure 3, the theoretical value of the bandpass amplification range of the circuit being 72.4-1592.4 HZ.
The method is suitable for amplifying the voice range audio signal of the electret microphone signal.
2. High pass amplification circuit example
Fig. 7 is a circuit diagram of an instantiated parameter of the high-pass (ac) amplifier circuit of fig. 4, where the theoretical value of the high-pass cutoff frequency of the circuit is 33.9HZ according to the value of the parameter of the high-pass amplifier circuit.
The electret microphone audio amplifier is suitable for audio signal amplification of electret microphone signals under general requirements.
3. Signal center point tracking migration locking circuit example
Fig. 8 is a circuit diagram of parameter instantiation of the signal center point tracking and shifting locking circuit in fig. 5, and finally the signal center point will be locked at one-half of the power voltage, and the circuit has a resistance of 100K in common, except that the resistance R1 in the integrating circuit has a value of 10K, which is for convenience of implementation and also for power saving.
For the sake of brevity, the present disclosure is not intended to be exhaustive, and various functional circuits may be designed in accordance with the principles, basic frames, and methods of this patent, such as a high-pass filter circuit unit instead of the low-pass filter circuit in this example, a modulation signal circuit, a comparison circuit, a limiting circuit, a locking circuit, etc., which are not necessarily limited to one.
Also, the technical features of this patent are not limited to only the technology and functional circuit types used by the above circuits.
The creativity, the novelty and the practicability of the patent are respectively highlighted as follows:
● it uses some amplifying circuits to make the amplitude difference signal (differential mode signal) of the two-way input signal equivalent to have "amplifying process channel", and the equivalent amplitude signal (common mode signal) equivalent to have "bypass channel", by processing each signal component in the input signal partially into equal amplitude signal, directly passing through the "bypass channel", and partially into amplitude difference signal, effectively amplifying and processing by the "amplifying process channel";
●, corresponding circuit structure and technical method for generating constant amplitude signal and amplitude difference signal respectively;
● provides a basic circuit and a development method which can be used for developing various functional circuits;
● show several example circuits.
In addition, there may be many existing circuits, which may have the technical features given in this patent in the form of specific examples and example circuits, and this should not affect the features of this patent as a generic technical solution, nor the unique technical features of various implementation example circuits in terms of design methods and specific circuits, and if the specific implementation details conflict with the existing patents, the specific implementation details can be avoided by changing the expression or technical implementation methods.
This patent does not intend to claim existing circuits, nor does it accept specific circuits to negate the common usage of this patent.

Claims (5)

1. A general circuit scheme for direct selection and amplification of weak signals in a complex signal environment and a realization method thereof,
● signal processing flow technical characteristics:
i. single end to ground voltage input signal VINIs processed into two paths of signals with the same signal content and signal amplitude;
each path of signal is processed by an independent signal processing unit respectively, and has two paths, and the through connection can be regarded as a special form of the signal processing unit;
the signal amplitude of a specific signal component between two paths of signals is correspondingly different and changed by carrying out asymmetric processing on the signal amplitude of some signal components in the two paths of signals or triggering some additional signals or even newly added modulation signals under conditions;
the two paths of signals are simultaneously transmitted to an amplification processing circuit;
the amplification processing circuit effectively amplifies a part (hereinafter referred to as an amplitude difference signal) of the signal amplitude difference between the two received signals, keeps the part (hereinafter referred to as a constant amplitude signal) with the same signal amplitude between the two signals unchanged, and outputs the part (hereinafter referred to as a constant amplitude signal) in a single-end voltage-to-ground signal form after the two signals are superposed;
and iii, designing a specific signal processing unit (group) to perform various forms of asymmetric processing operations on different signal contents in the two paths of signals, so as to realize a functional circuit for selectively amplifying and processing the different signal contents.
The signal processing flows and the signal characteristics have relevance, the signal processing process has integral integrity, and the signal processing process is comprehensive technical characteristics and is not suitable for segmentation judgment;
● technical characteristics of circuit constitution:
according to the functional division, the circuit comprises three parts, namely a constant amplitude signal generating circuit, an amplitude difference signal generating circuit and a signal selective amplification processing circuit;
wherein:
i. constant amplitude signal generation circuit:
the functional characteristics are as follows:
processing a single-end voltage-to-ground voltage input signal into two paths of signals with the same or closely related signal content and equal signal amplitude, namely constant amplitude signals;
the circuit is formed as follows:
the device consists of two parallel signal input units which can be omitted conditionally or an independent signal input module;
input connection:
single end to ground voltage input signal VINThe input ends of the two signal input units or the input ends of the signal input modules are connected simultaneously;
and (3) output connection:
the two paths of signals with the same content and the same signal amplitude, namely constant amplitude signals, are connected to an amplitude difference signal generating circuit;
an amplitude difference signal generation circuit:
the functional characteristics are as follows:
the signal processing units are respectively arranged for each path of signal output by the constant amplitude signal generating circuit, and the two mutually independent signal processing units carry out asymmetric processing and certain necessary symmetric processing on the signal amplitude of the selected signal component, namely, the signal amplitudes of the two paths of signals are different and changed to generate an amplitude difference signal or a quasi-constant amplitude signal of the corresponding signal component;
some additional signals can be generated in a condition triggering or signal self-generating mode to generate amplitude difference signals in various forms;
the circuit is formed as follows:
the device comprises two independent signal processing units with single-ended input and single-ended output interfaces, wherein each signal processing unit processes an output signal of a constant amplitude signal generating circuit;
a through connection is also a special form of signal processing unit;
input connection:
receiving two paths of signals from a constant amplitude signal generating circuit, wherein each path of signal is connected with the input end of a signal processing unit;
and (3) output connection:
two single-ended signals output by the two signal processing units are connected to the signal selective amplification processing circuit;
signal selective amplification processing circuit
The functional characteristics are as follows:
the two single-ended signals processed by the constant amplitude signal generating circuit and the amplitude difference signal generating circuit are input, and an amplitude difference signal part, namely a part with signal amplitude difference between the two signals, is effectively amplified and then is superposed on a passing constant amplitude signal part, namely a part with the same amplitude of the two signals, and is output in a single-ended voltage-to-ground voltage signal form;
the circuit is formed as follows:
the amplifier circuit unit comprises a double-end input single-end output circuit, wherein the signal amplification property meets the requirement of effectively amplifying amplitude difference signals (namely differential mode signals), the amplitude difference signals (namely common mode signals) are kept to pass through, and the amplitude difference signals and the common mode signals are superposed to be output by a single-end signal;
necessary signal input units can be arranged in front of the two input ends according to requirements;
input connection:
receiving two paths of signals from an amplitude difference signal generating circuit, wherein each path of signal is connected to a signal input unit which can be omitted conditionally before a signal input end;
and (3) output connection:
output in the form of single-ended voltage-to-ground signal with output signal VOUT；
The functional characteristics of the circuits of the above parts have relevance and integral integrity;
the circuit is simply recombined and formally divided, and the establishment of comprehensive technical characteristics is not influenced;
the realization of each functional circuit in the scheme and the realization method of the direct-selection amplification universal circuit for weak signals in complex signal environments can be realized by adopting various mature technologies or newly developed technologies as long as the characteristic requirements of signal processing are met.
2. According to the solution of claim 1, a universal base reference circuit for development is given:
an operational amplifier (hereinafter referred to as operational amplifier) technology is selected, an exemplary design of a part of circuits is carried out, all operational amplifiers are supplied with power by a single power supply, and the design positions of two signal processing units are reserved, so that the circuit can be used for further design of various actual functional circuits;
the development of a universal base reference circuit uses the following well-known basic circuit elements:
● signal follower circuit formed by single operational amplifier:
the positive phase input end of the operational amplifier inputs; the output end of the operational amplifier outputs;
the negative phase input end and the output end of the operational amplifier are directly connected;
three signal follower circuit units, signal follower circuits a1, a2, A3;
● Signal Selective Amplifier Circuit Unit:
from an operational amplifier AZ and a resistor R0, RZThe two paths of signals are input and output at a single end;
the two paths of signal input signals are marked as VA and VB respectively;
wherein:
■ A path of input signal VA is connected to the resistor R0, connected to the negative phase input end of the operational amplifier AZ through the resistor R0, and connected to the negative phase input end of the operational amplifier AZ through the resistor RZIs connected with the output end of the operational amplifier AZ;
■, one input signal VB is connected to the positive phase input end of the operational amplifier AZ;
the output end of the ■ operational amplifier AZ is used as the output end of the circuit;
the approximate signal amplification relation of the signal selective amplification circuit unit is as follows: vOUT＝VB+(RZ/R0)*(VB-VA)；
● the two signal processing units reserved each have the functional characteristics of:
■ single-ended input single-ended output;
■ can select certain signal components passing through to process the signal amplitude; some additional signals may also be generated autonomously or conditionally;
■ through connections can also be considered as a special form of signal processing unit;
the design positions of two signal processing units are reserved, namely a reserved signal processing unit A and a reserved signal processing unit B;
the circuit is characterized in that:
i. single end to ground voltage input signal VINAt the same time, the input ends of the signal follower circuits A1 and A2 are connected, so that the output end signals of the signal follower circuits A1 and A2 are all equal to VINThe same;
the output of the signal follower circuit a1 is connected to the reservation signal processing unit a,
the output of the signal follower circuit a2 is connected to the reserved signal processing unit B;
the output of the reserved signal processing unit A is connected to the VA input end of the signal selective amplifying circuit, namely a resistor R0 after passing through a signal following circuit A3; is connected to the negative phase input end of the operational amplifier AZ through a resistor R0 and then is connected to the negative phase input end of the operational amplifier AZ through a resistor RZIs connected with the output end of the operational amplifier AZ;
v. the output of the reserved signal processing unit B is connected to the VB input end of the signal selective amplifying circuit, namely the positive phase input end of the operational amplifier AZ;
vi, the output end of the operational amplifier AZ is a circuit output end, single-end voltage to ground is output in a mode of outputting, and an output signal is VOUT。
In the circuit, the same input signal and similar external circuit environment are prepared for reserving the signal processing units A and B;
on the basis of the constant-amplitude signals, the design of various signal processing amplifying circuits can be further completed only by selecting or designing a signal processing unit group capable of forming specific signal component amplitude difference signals;
the claims use of operational amplifier technology and sophisticated circuitry as technical implementation features, and the technology and implementation circuitry used should not be unduly limited to the scope of the other features of the patent.
3. According to claims 1-2, a band-pass amplifying circuit is provided;
the band-pass amplifying circuit replaces the reserved signal processing units A and B with two RC low-pass filter circuit actual circuits under the framework of the development universal basic reference circuit given by claim 2;
the band-pass amplifying circuit shares:
the 4 operational amplifier units powered by the single power supply are respectively operational amplifiers A1, A2, A3 and AZ;
the 4 resistors are respectively resistors R1, R2, R0 and RZ；
The 2 capacitors are capacitors C1, C2, respectively;
the technical characteristics of the connection relation of the components of the band-pass amplifying circuit are as follows:
i. single end to ground voltage input signal VINThe non-inverting input ends of the operational amplifier A1 and the operational amplifier A2 are connected simultaneously;
after the inverting input terminal of the operational amplifier a1 is connected to the output terminal of the operational amplifier a1, the inverting input terminal of the operational amplifier a 3526 is connected to the non-inverting input terminal of the operational amplifier A3 through the resistor R1, and the capacitor C1 is connected between the non-inverting input terminal of the operational amplifier A3 and the power ground:
iii, the inverting input end of the operational amplifier A3 is connected to the output end of the operational amplifier A3, then connected to the negative input end of the operational amplifier AZ through a resistor R0, and then connected to the negative input end of the operational amplifier AZ through a resistor RZThe output end is connected to the operational amplifier AZ;
after the inverting input end of the operational amplifier A2 is connected to the output end of the operational amplifier A2, the inverting input end of the operational amplifier A2 is connected to the positive phase input end of the operational amplifier AZ through a resistor R2, and the capacitor C2 is connected between the positive phase input end of the operational amplifier AZ and the power ground;
v. the output end of the operational amplifier AZ is the output end of the circuit, and the output signal is a single-end voltage signal V to earthOUT；
When the resistor R1 and the capacitor C1 form a low-pass filter circuit, the cut-off frequency is F1;
the cut-off frequency of a low-pass filter circuit consisting of the resistor R2 and the capacitor C2 is F2;
the signal processing characteristics of the band-pass amplifying circuit are as follows:
the signals with the signal frequency between F1 and F2 are effectively amplified, and the amplification ratio is equal to (R)Z/R0);
meanwhile, amplification processing of other signal components is inhibited;
the techniques and example circuits used in the claims are intended to be exemplary of techniques for implementing the functions of the circuit in question using operational amplifier techniques and sophisticated circuitry, and are not intended to unduly limit the scope of the claims and their technical features.
4. According to claims 1-2, a high-pass (ac) amplifying circuit is provided;
the circuit comprises a capacitor C1, two operational amplifiers A1, AZ, and three resistors R1, R0, RZComposition is carried out;
the main technical characteristics of the connection relation of the components are as follows:
i. single end to ground voltage input signal VINIs connected to a resistor R0, is connected to the negative phase input end of the operational amplifier AZ after passing through a resistor R0, and then passes through a resistor RZThe output end is connected to the operational amplifier AZ;
ii single-ended input signal VINThe negative phase input end of the operational amplifier A1 is connected to the output end of the operational amplifier A1 and then connected to a resistor R1, and is connected to the positive phase input end of the operational amplifier AZ through a resistor R1, and a capacitor C1 is connected between the positive phase input end of the operational amplifier AZ and the ground;
iii, the output end of the operational amplifier AZ is a circuit output end, and the output signal is a single-ended voltage signal V to groundOUT；
The circuit is a high-pass amplifying circuit, and the cut-off frequency of the circuit is the same as that of a low-pass filter circuit consisting of a resistor R1 and a capacitor C1;
when the resistor R1 and the capacitor C1 form an integrating circuit, the circuit can be regarded as an alternating current signal amplifying circuit;
circuit amplification factor and (R)Z/R0);
the techniques and example circuits used in the claims are intended to be exemplary of techniques for implementing the functions of the circuit in question using operational amplifier techniques and sophisticated circuitry, and are not intended to unduly limit the scope of the claims and their technical features.
5. According to the contents of claims 1-2, a signal center point tracking transition locking circuit is given;
the circuit consists of an integrating circuit unit, a signal amplifying unit, a plurality of signal following circuits and a resistance voltage dividing circuit;
wherein:
the signal amplifying unit consists of an operational amplifier AZ and resistors R0, RZIn the circuit, resistors R0, RZThe resistance values are equal;
the integrating circuit unit consists of a resistor R1 and a capacitor C1;
the signal following circuit consists of operational amplifiers A1, A2 and A3;
two component voltage resistors: resistors R2, R3 and resistors R4, R5;
the operational amplifier is powered by a single power supply;
the technical characteristics of the circuit are as follows:
single end to ground voltage input signal VINSimultaneously to two signal processing channels, wherein:
i.VINone path of resistor R0 connected to the amplifying circuit unit is connected to the negative phase input end of the operational amplifier AZ through R0 and then through the resistor RZThe output end is connected to the operational amplifier AZ;
ii.VINthe other path is connected to the positive input end of an operational amplifier A1, the negative input end and the output end of the operational amplifier A1 are connected to form a signal follower circuit, the output end of the operational amplifier A1 is connected to a resistor R1, the negative input end and the output end of the operational amplifier A1 are connected to the positive input end of an operational amplifier A3 through a resistor R1, and a capacitor C1 is connected between the positive input end of the operational amplifier A3 and the power groundThe resistor R1 and the capacitor C1 form an integrating circuit to obtain a signal VINI.e. the signal center point level VCenter of a shipThe positive phase input end of the operational amplifier A3 is VCenter of a shipThe negative phase input end and the output end of the operational amplifier A3 are connected to form a signal following circuit, and a signal V is obtained at the output end of the operational amplifier A3Center of a ship；
The voltage of the power supply is divided by two resistors R2 and R3 to obtain VREF，VREFOr directly connected from outside, and connected to the positive input terminal of the operational amplifier A2, the negative input terminal and the output terminal of the operational amplifier A2 are directly connected to form a signal follower circuit, and the output terminal of the operational amplifier A2 obtains the signal VREF；
Signal V at the output of signal follower circuit a3Center of a shipAnd the output end signal V of the signal following circuit A2REFAfter voltage division by equivalent resistors R4 and R5, a signal (V) is obtained at the connection point of the resistors R4 and R5Center of a ship+VREF) The/2 is connected to the positive phase input end of the operational amplifier AZ of the amplifying circuit;
v. obtaining output signal at output end of operational amplifier AZ of amplifying circuit, which is single end voltage signal V to groundOUT；
The circuit can lock the signal center point of the output signal at VREFAt least one of (1) and (b);
the present circuit is a specific example, and the technology and circuit type used should not be unduly limited to the technical features of other claims of this patent.
CN202010370267.5A 2020-04-29 2020-04-29 Direct-selection amplification universal circuit scheme for weak signals in complex signal environment and implementation method Pending CN111654784A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010370267.5A CN111654784A (en) 2020-04-29 2020-04-29 Direct-selection amplification universal circuit scheme for weak signals in complex signal environment and implementation method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010370267.5A CN111654784A (en) 2020-04-29 2020-04-29 Direct-selection amplification universal circuit scheme for weak signals in complex signal environment and implementation method

Publications (1)

Publication Number Publication Date
CN111654784A true CN111654784A (en) 2020-09-11

Family

ID=72348244

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010370267.5A Pending CN111654784A (en) 2020-04-29 2020-04-29 Direct-selection amplification universal circuit scheme for weak signals in complex signal environment and implementation method

Country Status (1)

Country Link
CN (1) CN111654784A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112910431A (en) * 2021-01-20 2021-06-04 四川湖山电器股份有限公司 Audio frequency amplitude limiting circuit and equipment with power supply rail tracking characteristic based on single power supply

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101599766A (en) * 2009-06-09 2009-12-09 上海华魏光纤传感技术有限公司 The differential-mode component extraction method of light signal and device thereof
CN101820256A (en) * 2010-04-21 2010-09-01 无锡伯顿电子科技有限公司 Sensor signal amplifying and conditioning circuit
CN202051701U (en) * 2011-04-15 2011-11-30 北京正业德盈科技有限公司 Physiological signal collecting electrode and collecting amplifying circuit
CN104348431A (en) * 2013-07-31 2015-02-11 快捷半导体(苏州)有限公司 Common-mode feedback differential amplification circuit, method and integrated circuit
US20150087250A1 (en) * 2013-09-23 2015-03-26 Asustek Computer Inc. Radio frequency communication system and noise isolation method applied thereto
CN205665382U (en) * 2016-04-28 2016-10-26 哈尔滨理工大学 Enlarged circuit that draws of difference mode signal
WO2018047437A1 (en) * 2016-09-08 2018-03-15 株式会社ソシオネクスト Audio signal processing device

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101599766A (en) * 2009-06-09 2009-12-09 上海华魏光纤传感技术有限公司 The differential-mode component extraction method of light signal and device thereof
CN101820256A (en) * 2010-04-21 2010-09-01 无锡伯顿电子科技有限公司 Sensor signal amplifying and conditioning circuit
CN202051701U (en) * 2011-04-15 2011-11-30 北京正业德盈科技有限公司 Physiological signal collecting electrode and collecting amplifying circuit
CN104348431A (en) * 2013-07-31 2015-02-11 快捷半导体(苏州)有限公司 Common-mode feedback differential amplification circuit, method and integrated circuit
US20150087250A1 (en) * 2013-09-23 2015-03-26 Asustek Computer Inc. Radio frequency communication system and noise isolation method applied thereto
CN205665382U (en) * 2016-04-28 2016-10-26 哈尔滨理工大学 Enlarged circuit that draws of difference mode signal
WO2018047437A1 (en) * 2016-09-08 2018-03-15 株式会社ソシオネクスト Audio signal processing device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112910431A (en) * 2021-01-20 2021-06-04 四川湖山电器股份有限公司 Audio frequency amplitude limiting circuit and equipment with power supply rail tracking characteristic based on single power supply
CN112910431B (en) * 2021-01-20 2022-12-30 四川湖山电器股份有限公司 Audio frequency amplitude limiting circuit and equipment with power supply rail tracking characteristic based on single power supply

Similar Documents

Publication Publication Date Title
CN103414442B (en) High accuracy fully-differential amplifier based on wave chopping technology
CN210142143U (en) High-precision current sampling circuit
CN105182061B (en) A kind of AC current collecting circuit that ceramic machinery equipment uses
CN102769435A (en) Differential amplifying circuit capable of automatically adjusting amplification factor
CN103236864B (en) The accepted theory that a kind of chip area reduces
CN113922776B (en) C/V conversion circuit based on switched capacitor type common mode feedback charge amplifier
US7408392B2 (en) PWM-to-voltage converter circuit and method
CN111654784A (en) Direct-selection amplification universal circuit scheme for weak signals in complex signal environment and implementation method
US7417439B2 (en) Impedance conversion circuit and integrated circuit including thereof
Tangsrirat Simple BiCMOS realization of full balanced voltage differencing buffered amplifier
CN214412583U (en) Power supply current equalizing circuit, power supply module, power supply system and computer equipment
CN107070426A (en) A kind of amplifier and its implementation
CN114400977A (en) Analog signal processing circuit and DC offset voltage elimination method
CN103427771A (en) Balanced transformer less (BTL) differential type audio power amplification circuit
KR20030053492A (en) Universal instrumentation amplifier
Ferreira et al. Analog integrated lock-in amplifier for optical sensors
CN112821741A (en) Power supply current equalizing circuit, power supply module, power supply system and computer equipment
CN106505985A (en) Single-ended to differential conversion circuit and signal processing module
RU2394364C1 (en) Two-channel controlled alternating current amplifier
CN102710239B (en) Broadband orthogonal signal generator
CN208461799U (en) A kind of amplifying circuit
CN109672423A (en) Integrated state variable filter
CN109115849A (en) electrochemical sensor circuit
EP4329194A1 (en) Fully differential amplifier
CN103414439B (en) A kind of fully differential power current amplifier with noise-cancellation circuit

Legal Events

Date Code Title Description
DD01 Delivery of document by public notice

Addressee: Bai Jianmin

Document name: Notification to Make Rectification

DD01 Delivery of document by public notice
PB01 Publication
PB01 Publication
DD01 Delivery of document by public notice

Addressee: Bai Jianmin

Document name: Notification of passing the preliminary examination of patent application for invention

DD01 Delivery of document by public notice
DD01 Delivery of document by public notice

Addressee: Bai Jianmin

Document name: Notice of publication of application for patent for invention

DD01 Delivery of document by public notice
DD01 Delivery of document by public notice

Addressee: Bai Jianmin

Document name: Notification before the expiration of the request period for substantive examination of an invention patent application

DD01 Delivery of document by public notice
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
DD01 Delivery of document by public notice

Addressee: Bai Jianmin

Document name: Notice of First Examination Opinion