CN101964641A - Double secondary-ring tracking band-pass integration circuit based on pulse width modulation and control method thereof - Google Patents

Abstract

The invention discloses a double secondary-ring tracking band-pass integration circuit based on pulse width modulation and a control method thereof, comprising an integration element and an inverse proportion element, wherein the integration element comprises a first operational amplifier. The double secondary-ring tracking band-pass integration circuit comprises a third operational amplifier of which the output end is connected with the integration element, and a first resistor and a first capacitor forming a second feedback loop are connected between an inverse input end and an output end; the output end of the first operational amplifier is connected with the inverse proportion element; and the output end of the inverse proportion element is connected with the inverse input end of the third operational amplifier by a third resistor. The invention also comprises feedback loop analog electronic switches and a second analog electronic switch, wherein the feedback loop analog electronic switches receive the signal of the same control end, and are connected between one connected end of the first resistor and the third resistor and the inverse input end of the third operational amplifier in series or are respectively connected to a first resistor branch and a third resistor branch in series, and the second analog electronic switch is connected with the second resistor in series. The invention combines a frequency tracking filter function with an integration function and has simple circuit structure.

Description

Biquadratic ring track band general integral circuit and control method thereof based on pulse-width modulation

Technical field

The present invention relates to a kind of integrating circuit and control method thereof, relate in particular to a kind of biquadratic ring track band general integral circuit and control method thereof based on pulse-width modulation.

Background technology

Bandwidth-limited circuit and integrating circuit are used very extensive in practice, bandwidth-limited circuit has the effect of the unwanted interference signal of filtering, and integrating circuit is not only as integral operation, and utilizes its charge and discharge process can also realize time-delay, regularly and produce various waveforms.

In actual applications, need circuit to reach a kind of like this function sometimes: should carry out frequency-tracking filtering to a certain processed frequency signal, also require simultaneously requiring the Frequency point place to carry out integration to this signal.General implementation is that frequency-tracking filter function and integrating function are separately realized, promptly to integration after the first filtering of processed signal, filtering behind the perhaps first integration.The shortcoming of this scheme is that circuit structure complexity, design and manufacturing cost are higher.

Summary of the invention

The objective of the invention is to overcome the defective of prior art, and a kind of biquadratic ring track band general integral circuit and control method thereof based on pulse-width modulation is provided, it unites two into one the realization of frequency-tracking filter function and integrating function, and circuit structure is simple.

The technical scheme that realizes above-mentioned purpose is:

A kind of biquadratic ring track band general integral circuit based on pulse-width modulation of one of the present invention comprises integral element and anti-phase proportional component, and described integral element includes one first operational amplifier, wherein,

Described biquadratic ring track band general integral circuit comprises one the 3rd operational amplifier, the in-phase input end ground connection of the 3rd operational amplifier, inverting input is by one the 4th resistance receiving inputted signal, its output links to each other with described integral element, first resistance that also is connected with one first electric capacity between the inverting input of described the 3rd operational amplifier and the output and is connected in parallel with this first electric capacity, the output of described the 3rd operational amplifier links to each other to constitute second feedback loop with the inverting input of described the 3rd operational amplifier with first electric capacity through first resistance;

The in-phase input end ground connection of first operational amplifier in the described integral element, inverting input links to each other with the output of described the 3rd operational amplifier by one second resistance, output links to each other with the input of described anti-phase proportional component, also is connected with one second electric capacity between the inverting input of described first operational amplifier and the output;

Described anti-phase proportional component receives the signal of described integral element output, and the output of this anti-phase proportional component links to each other to constitute first feedback loop with the inverting input of described the 3rd operational amplifier by one the 3rd resistance;

Described biquadratic ring track band general integral circuit also comprises the feedback loop simulant electronic switch and second simulant electronic switch, the described feedback loop simulant electronic switch and second analog switch receive the pulse-width signal of same control end output, described second analog switch is connected with described second resistance, described feedback loop simulant electronic switch is serially connected with between the inverting input of interconnective end of first and third resistance and the 3rd operational amplifier, perhaps is serially connected with respectively on the branch road at first and third resistance place.

The above-mentioned biquadratic ring track band general integral circuit based on pulse-width modulation, wherein, described feedback loop simulant electronic switch is serially connected with between the inverting input of the interconnective end to the of first and third resistance three operational amplifiers.

The above-mentioned biquadratic ring track band general integral circuit based on pulse-width modulation, wherein, described feedback loop simulant electronic switch is two, is serially connected with respectively on the branch road at the branch road at the described first resistance place and the second resistance place.

Above-mentioned biquadratic ring track band general integral circuit based on pulse-width modulation, wherein, a described feedback loop simulant electronic switch is connected between the inverting input of described the 3rd resistance and the 3rd operational amplifier or is connected between the output of described the 3rd resistance and anti-phase proportional component; Described another feedback loop simulant electronic switch is connected between the inverting input of described first resistance and the 3rd operational amplifier or is connected between the output of described first resistance and described the 3rd operational amplifier.

Above-mentioned biquadratic ring track band general integral circuit based on pulse-width modulation, wherein, described second simulant electronic switch is connected between the output of described the 3rd operational amplifier and second resistance or is connected between the inverting input of described second resistance and first operational amplifier.

The control method of a kind of biquadratic ring track band general integral circuit based on pulse-width modulation of two of the present invention, wherein,

In the control end input cycle is the pulse-width modulation control signal of T, and the time of simulant electronic switch closure is T in one-period _T, wherein:

The period T of described pulse-width modulation control signal determines according to being integrated signal frequency f, Described switch closure time T _TBe that ON time is

N be pulse-width modulation control signal frequency be integrated the multiple of signal frequency, n is more than or equal to 100, f _TBe full turn-on frequency.

The invention has the beneficial effects as follows: circuit of the present invention has the logical tracking filter function of band, and also has the function of centre frequency place signal being carried out integration simultaneously, the present invention is suitable for that requirement is carried out integration to a certain frequency signal and this signal is mixed with the occasion of other frequency interferences signals, have simple in structure, design advantage easily.

Description of drawings

Fig. 1 is one of the present invention's the circuit diagram based on first embodiment of the biquadratic ring track band general integral circuit of pulse-width modulation;

Fig. 2 is one of the present invention's the circuit diagram based on second embodiment of the biquadratic ring track band general integral circuit of pulse-width modulation.

Embodiment

The invention will be further described below in conjunction with accompanying drawing.

See also Fig. 1 and Fig. 2, there is shown a kind of biquadratic ring track band general integral circuit based on pulse-width modulation of one of the present invention, comprise integral element 1 and anti-phase proportional component 2, integral element 1 includes one first operational amplifier 3, wherein:

Biquadratic ring track band general integral circuit comprises the in-phase input end ground connection of one the 3rd operational amplifier, 4, the three operational amplifiers 4, and inverting input is by one the 4th resistance R ₄Receiving inputted signal, its output links to each other with integral element 1, also is connected with one first capacitor C between the inverting input of the 3rd operational amplifier 4 and the output ₁And with this first capacitor C ₁First resistance R that is connected in parallel ₁, the output of the 3rd operational amplifier 4 is through first resistance R ₁With first capacitor C ₁Link to each other to constitute second feedback loop 6 with the inverting input of the 3rd operational amplifier 1;

The in-phase input end ground connection of first operational amplifier 3 in the integral element 1, inverting input is by one second resistance R ₂Link to each other with the output of the 3rd operational amplifier 4, output links to each other with the input of anti-phase proportional component 2, also is connected with one second capacitor C between the inverting input of first operational amplifier 1 and the output ₂

Anti-phase proportional component 2 receives the signal of integral element 1 output, and the output of this anti-phase proportional component 2 is by one the 3rd resistance R ₃Link to each other to constitute first feedback loop 5 with the inverting input of the 3rd operational amplifier 4;

Biquadratic ring track band general integral circuit also comprises the feedback loop simulant electronic switch and the second simulation electronic S2 switch, the feedback loop simulant electronic switch and the second analog switch S2 receive the pulse-width signal of same control end C output, the second analog switch S2 and second resistance R ₂Series connection, the feedback loop simulant electronic switch is serially connected with first and third resistance R ₁, R ₃Between the inverting input of an interconnective end and the 3rd operational amplifier 4, perhaps be serially connected with first and third resistance R respectively ₁, R ₃On the branch road at place.

The second simulant electronic switch S2 is connected in the output and second resistance R of the 3rd operational amplifier 4 ₂Between or be connected in second resistance R ₂And between the inverting input of first operational amplifier 3.

See also Fig. 1, among this embodiment, the feedback loop simulant electronic switch is one, i.e. feedback loop simulant electronic switch S1, and this switch series is connected to first and third resistance R ₁, R ₃Between the inverting input of an interconnective end and the 3rd operational amplifier 4.

See also Fig. 2, be the second embodiment of the present invention, in this embodiment, the feedback loop simulant electronic switch is two, is respectively S1 and S3, and these two switches are serially connected with first and third resistance R respectively ₁, R ₃On the branch road at place, wherein:

A feedback loop simulant electronic switch S3 is connected in the 3rd resistance R ₃And between the inverting input of the 3rd operational amplifier 4 or the 3rd resistance R that is connected in ₃And between the output of anti-phase proportional component 2; Another feedback loop simulant electronic switch S1 is connected in first resistance R ₁And between the inverting input of the 3rd operational amplifier 4 or be connected in first resistance R ₁And between the output of the 3rd operational amplifier 4.

Circuit of the present invention has been rabbeted the feedback loop simulant electronic switch and the second simulation electronic S2 in biquadratic ring endless belt pass filter circuit.The feedback loop simulant electronic switch and the second simulation electronic S2 can open or closure by controlling it in control end C adding control signal.In the present invention, suppose at C termination logic high, the feedback loop simulant electronic switch and the second simulation electronic S2 closure, and at C termination logic low, the feedback loop simulant electronic switch and the second simulation electronic S2 disconnect.

The control method of a kind of biquadratic ring track band general integral circuit based on pulse-width modulation of two of the present invention comprises the steps:

In the control end input cycle is the pulse-width modulation control signal of T, and the time of simulant electronic switch closure is T in one-period _T, wherein:

The period T of pulse-width modulation control signal determines according to being integrated signal frequency f,

The switch closure time T _TBe that ON time is

N be pulse-width modulation control signal frequency be integrated the multiple of signal frequency, n is more than or equal to 100, f _TBe full turn-on frequency.

Operation principle:

The present invention is by importing suitable pulse-width signal at control end C, the break-make of the Control and Feedback loop simulant electronic switch and the second simulation electronic S2, the equivalence value of change resistance, i.e. first resistance R ₁, second resistance R ₂, the 3rd resistance R ₃Equivalence value, thereby change the input-output characteristic of circuit.In the C end input cycle is the control signal of T, and the time of switch closure is T in one-period _T, T _TBe the fixed value that designs as required, then first resistance R in period T ₁Equivalent mean value be

$R_{1e}=\frac{T}{{\mathrm{<figure-callout\; id="1"\; label="T\; T\; R"\; filenames="HDA0000027769210000011.png,HDA0000027769210000012.png"\; state="\{\{state\}\}">T</figure-callout>}}_T}{R}_{}{}_1;---\left(1\right)$

In the formula, T _TFor switch control ON time, be fixed value; T is the cycle of switch controlling signal.Constant as far as possible for making at the equivalence value of one-period T internal feedback resistance, the frequency of desirable switch controlling signal be integrated signal frequency n doubly, according to result of the test, generally get n＞100.Then have

$R_{1e}=\frac{T}{{\mathrm{<figure-callout\; id="1"\; label="T\; T\; R"\; filenames="HDA0000027769210000011.png,HDA0000027769210000012.png"\; state="\{\{state\}\}">T</figure-callout>}}_T}{R}_{}{}_1=\frac{n/T_T}{n/\mathrm{<figure-callout\; id="1"\; label="T\; R"\; filenames="HDA0000027769210000011.png,HDA0000027769210000012.png"\; state="\{\{state\}\}">T</figure-callout>}}{R}_{}{}_1=\frac{f_{\mathrm{<figure-callout\; id="1"\; label="T\; f\; R"\; filenames="HDA0000027769210000011.png,HDA0000027769210000012.png"\; state="\{\{state\}\}">T</figure-callout>}}}{f}{R}_{}{}_1=\frac{{\mathrm{\&omega;}}_T}{\mathrm{\&omega;}}{R}_1---\left(2\right)$

In the formula, f is for being integrated signal frequency, and ω is for being integrated signal angular frequency, f _T, ω _TBe called full turn-on frequency, full angle of flow frequency, be fixed value.Obviously, when signal frequency be f _TThe time, R _1eBe R ₁

Similarly, R ₂, R ₃Equivalent mean value be

$R_{2e}=\frac{{\mathrm{\&omega;}}_T}{\mathrm{\&omega;}}{\mathrm{<figure-callout\; id="3"\; label="R"\; filenames="HDA0000027769210000011.png,HDA0000027769210000012.png"\; state="\{\{state\}\}">R</figure-callout>}}_3,R_{3e}=\frac{{\mathrm{\&omega;}}_T}{\mathrm{\&omega;}}{R}_3---\left(3\right)$

The input-output characteristic that can be got Fig. 1 circuit by last surface analysis is

$H\left(s\right)=\frac{U_o\left(s\right)}{U_i\left(s\right)}=-\frac{\frac{1}{R_4{C}_1}\mathrm{<figure-callout\; id="2"\; label="s\; s"\; filenames="HDA0000027769210000011.png,HDA0000027769210000012.png"\; state="\{\{state\}\}">s</figure-callout>}}{s^{}}=-\frac{H{\mathrm{\&omega;}}_0\mathrm{<figure-callout\; id="2"\; label="s\; s"\; filenames="HDA0000027769210000011.png,HDA0000027769210000012.png"\; state="\{\{state\}\}">s</figure-callout>}}{s^{}}---\left(4\right)$

By formula (4) as can be known, Fig. 1 circuit has bandpass characteristics, and centre frequency is

${\mathrm{\&omega;}}_0=\sqrt{\frac{1}{R_{2e}{R}_{3e}{C}_1{\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA0000027769210000011.png,HDA0000027769210000012.png"\; state="\{\{state\}\}">C</figure-callout>}}_2}}=\frac{\mathrm{\&omega;}}{{\mathrm{\&omega;}}_T}\sqrt{\frac{1}{R_2{R}_3{C}_1{C}_2}}---\left(5\right)$

Quality factor are

$Q=\sqrt{\frac{R_{1e}^2{C}_1}{R_{2e}{R}_{3e}{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HDA0000027769210000011.png,HDA0000027769210000012.png"\; state="\{\{state\}\}">C</figure-callout>}}_1}}=\sqrt{\frac{R_1^2{C}_1}{R_2{R}_3{C}_2}}---\left(6\right)$

The multiplication factor at centre frequency place is

$A=\mathrm{HQ}=\frac{{\mathrm{\&omega;}}_T}{\mathrm{\&omega;}}\frac{R}{R_4}---\left(7\right)$

If get

Then there is centre frequency to be

ω ₀＝ω (8)

The multiplication factor at centre frequency place is

$A=\frac{1}{\mathrm{\&omega;}}\frac{R_2}{{\mathrm{<figure-callout\; id="4"\; label="R"\; filenames="HDA0000027769210000011.png"\; state="\{\{state\}\}">R</figure-callout>}}_4}\sqrt{\frac{1}{R_1{R}_3{C}_1{C}_2}}---\left(9\right)$

By formula (9) as can be known, the multiplication factor A at the logical centre frequency place of the band of Fig. 1 circuit be integrated signal frequency ω and be inverse relation, so function of the existing bandpass filtering of Fig. 1 circuit has pair signal to carry out the function of integration again.

Circuit method to set up of the present invention:

(1) selected parameter n determines full turn-on frequency or full angle of flow frequency f _T, ω _TFull turn-on frequency has determined the working range of circuit.

(2) according to being integrated the period T that signal frequency f determines pulse-width modulation control signal.The cycle of pulse-width modulation control signal

Wherein ON time is

(3) determine the model of amplifier, select suitable amplifier according to the purposes of using, its alternation rule can adopt general amplifier selective rule.Determine each electric capacity and each resistance value, make the requirement of satisfying formula (6)～(9) defined.

(4) carrying out circuit performance according to formula (6)～(9) adjusts.

To illustrate below:

The band general integral circuit that pilot production can be worked below 159.155Hz with circuit design of the present invention, design objective is: centre frequency changes with being integrated signal frequency, and quality factor are 10, and the multiplication factor at centre frequency place is

Design: (1) gets n=100, f _T=159.155Hz, then

ω _T=2 π f _T=1000rad/s, the conducting width of pulse-width modulation control signal is 62.8 μ s, is fixed value.

(2) selected amplifier model is AD711, gets C ₁=C ₂=0.1 μ F, by Desirable R ₂=R ₃=10k Ω.By Q=10, R ₁=100k Ω.Get R ₄=100k Ω.

(3) cycle of pulse-width modulation control signal

For example, carry out integral operation to the sine wave of 50Hz, then the cycle of pulse-width modulation control signal is 200 μ s.

(4) through calculating, designed circuit meets the demands.

Behind the selected component parameter of the method according to this invention, can directly implement according to the circuit diagram among the present invention.

The control signal of simulation electronic control switch involved in the present invention can adopt general circuit hardware to realize, also can adopt microprocessor to implement by the method for software programming.

Above embodiment is only for the usefulness that the present invention is described, but not limitation of the present invention, person skilled in the relevant technique, under the situation that does not break away from the spirit and scope of the present invention, can also make various conversion or modification, therefore all technical schemes that are equal to also should belong to category of the present invention, should be limited by each claim.

Claims (6)

1. the biquadratic ring track band general integral circuit based on pulse-width modulation comprises integral element and anti-phase proportional component, and described integral element includes one first operational amplifier, it is characterized in that,

Described biquadratic ring track band general integral circuit comprises one the 3rd operational amplifier, the in-phase input end ground connection of the 3rd operational amplifier, inverting input is by one the 4th resistance receiving inputted signal, its output links to each other with described integral element, first resistance that also is connected with one first electric capacity between the inverting input of described the 3rd operational amplifier and the output and is connected in parallel with this first electric capacity, the output of described the 3rd operational amplifier links to each other to constitute second feedback loop with the inverting input of described the 3rd operational amplifier with first electric capacity through first resistance;

The in-phase input end ground connection of first operational amplifier in the described integral element, inverting input links to each other with the output of described the 3rd operational amplifier by one second resistance, output links to each other with the input of described anti-phase proportional component, also is connected with one second electric capacity between the inverting input of described first operational amplifier and the output;

Described anti-phase proportional component receives the signal of described integral element output, and the output of this anti-phase proportional component links to each other to constitute first feedback loop with the inverting input of described the 3rd operational amplifier by one the 3rd resistance;

Described biquadratic ring track band general integral circuit also comprises the feedback loop simulant electronic switch and second simulant electronic switch, the described feedback loop simulant electronic switch and second analog switch receive the pulse-width signal of same control end output, described second analog switch is connected with described second resistance, described feedback loop simulant electronic switch is serially connected with between the inverting input of interconnective end of first and third resistance and the 3rd operational amplifier, perhaps is serially connected with respectively on the branch road at first and third resistance place.

2. the biquadratic ring track band general integral circuit based on pulse-width modulation according to claim 1, it is characterized in that described feedback loop simulant electronic switch is serially connected with between the inverting input of the interconnective end to the of first and third resistance three operational amplifiers.

3. the biquadratic ring track band general integral circuit based on pulse-width modulation according to claim 1, it is characterized in that, described feedback loop simulant electronic switch is two, is serially connected with respectively on the branch road at the branch road at the described first resistance place and the second resistance place.

4. the biquadratic ring track band general integral circuit based on pulse-width modulation according to claim 3, it is characterized in that a described feedback loop simulant electronic switch is connected between the inverting input of described the 3rd resistance and the 3rd operational amplifier or is connected between the output of described the 3rd resistance and anti-phase proportional component; Described another feedback loop simulant electronic switch is connected between the inverting input of described first resistance and the 3rd operational amplifier or is connected between the output of described first resistance and described the 3rd operational amplifier.

5. the biquadratic ring track band general integral circuit based on pulse-width modulation according to claim 1, it is characterized in that described second simulant electronic switch is connected between the output of described the 3rd operational amplifier and second resistance or is connected between the inverting input of described second resistance and first operational amplifier.

6. the control method based on the biquadratic ring track band general integral circuit of pulse-width modulation based on claim 1 is characterized in that,

In the control end input cycle is the pulse-width modulation control signal of T, and the time of simulant electronic switch closure is T in one-period _T, wherein:

The period T of described pulse-width modulation control signal determines according to being integrated signal frequency f, Described switch closure time T _TBe that ON time is

N be pulse-width modulation control signal frequency be integrated the multiple of signal frequency, n is more than or equal to 100, f _TBe full turn-on frequency.

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