CN214959454U - Multiple negative feedback circuit - Google Patents
Multiple negative feedback circuit Download PDFInfo
- Publication number
- CN214959454U CN214959454U CN202120540759.4U CN202120540759U CN214959454U CN 214959454 U CN214959454 U CN 214959454U CN 202120540759 U CN202120540759 U CN 202120540759U CN 214959454 U CN214959454 U CN 214959454U
- Authority
- CN
- China
- Prior art keywords
- operational amplifier
- resistor
- feedback branch
- circuit
- capacitor
- 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.)
- Active
Links
Images
Landscapes
- Amplifiers (AREA)
Abstract
The utility model relates to the technical field of feedback circuits, and discloses a multiple negative feedback circuit with reduced distortion and wider bandwidth, which comprises an operational amplifier, an output circuit, an amplifier, a first level feedback branch and an alternating current loop feedback branch, wherein one end of the direct current loop feedback branch is connected with the output end of the output circuit and is used for acquiring one path of electric signal amplified by the output circuit, and the direct current loop feedback branch feeds back the other path of electric signal to the inverting end of the operational amplifier; the alternating current loop feedback branch feeds back the other path of electric signal to the inverting terminal of the operational amplifier; the first current-stage feedback branch, the direct current loop feedback branch and the alternating current loop feedback branch are used for feeding back electric signals, so that the overall gain and distortion of the operational amplifier are reduced.
Description
Technical Field
The utility model relates to a feedback circuit technical field, more specifically say, relate to a multiple negative feedback circuit.
Background
Negative feedback, that is, taking out a part of the output signal of the amplifier, and returning it to the input end opposite to the output signal in a certain way, so as to produce a difference with the input end, weaken the strength of the original input signal, and reduce the gain of the amplifier. At present, a feedback circuit of an existing amplifier is generally unipolar feedback, only one feedback signal is transmitted to an input end, and when the amplifier is actually used, the bandwidth of the amplifier is narrow, and the effect of reducing distortion is not ideal.
Therefore, how to increase the effective operating bandwidth of the amplifier and reduce the signal distortion of the amplifier circuit is a technical problem that needs to be solved by those skilled in the art to achieve the above practical effects.
Disclosure of Invention
The to-be-solved technical problem of the utility model lies in, the feedback circuit to the above-mentioned existing amplifier of prior art generally is monopole feedback, only transmits a feedback signal to input, and in the time of in-service use, the bandwidth of ubiquitous amplifier is too narrow, and reduces the not good defect of effect of distortion, the utility model provides a reduce the multiple negative feedback circuit of the good and effective work bandwidth broad of distortion effect.
The utility model provides a technical scheme that its technical problem adopted is: a multiple negative feedback circuit is constructed, comprising:
the operational amplifier receives an externally input electric signal at a non-inverting end thereof and gains the electric signal;
one end of the output circuit is connected with the output end of the operational amplifier and is used for acquiring the other path of electric signal gained by the operational amplifier and amplifying the other path of electric signal;
the input end of the amplifier is connected with the output end of the operational amplifier, and the output end of the operational amplifier is coupled with the output end of the output circuit;
a first local feedback branch, one end of which is connected to the output end of the operational amplifier and is used for obtaining another electric signal gained by the operational amplifier, and the other end of which is coupled to the inverting end of the operational amplifier, wherein the first local feedback branch feeds back the electric signal to the inverting end of the operational amplifier;
one end of the direct current loop feedback branch is connected with the output end of the output circuit and used for acquiring the other path of the electric signal amplified by the output circuit, the other end of the direct current loop feedback branch is coupled with the inverting end of the operational amplifier, and the direct current loop feedback branch feeds the other path of the electric signal back to the inverting end of the operational amplifier;
one end of the alternating current loop feedback branch is connected with the output end of the output circuit and used for acquiring another path of electric signal gained by the operational amplifier, the other end of the alternating current loop feedback branch is coupled with the inverting end of the operational amplifier, and the other path of electric signal is fed back to the inverting end of the operational amplifier by the alternating current loop feedback branch;
and the overall gain and distortion of the operational amplifier are reduced through the electric signals fed back by the first current-stage feedback branch, the direct current loop feedback branch and the alternating current loop feedback branch.
In some embodiments, the first current stage feedback branch comprises a third capacitor, one end of the third capacitor is connected with the output end of the operational amplifier,
the other end of the third capacitor is coupled to the inverting terminal of the operational amplifier.
In some embodiments, the amplifier is provided with a second and a third present-stage feedback branch,
the input end of the third current-stage feedback branch circuit is connected with the output end of the operational amplifier;
the input end of the second current-stage feedback branch circuit is connected with the output end of the third current-stage feedback branch circuit,
the output end of the second current-stage feedback branch is coupled to the inverting end of the operational amplifier.
In some embodiments, the output circuit includes a first transistor and a second transistor,
the base electrodes of the first triode and the second triode are respectively connected with the output end of the operational amplifier,
the emitter of the first triode is connected with the emitter of the second triode,
the collector of the first triode is connected with the positive electrode of the power supply,
and the collector of the second triode is connected with the negative electrode of the power supply.
In some embodiments, the dc loop feedback branch comprises a first resistor, one end of the first resistor is connected to the emitter of the first transistor and the emitter of the second transistor respectively,
the other end of the first resistor is coupled to the inverting terminal of the operational amplifier.
In some embodiments, the dc loop feedback branch further comprises a sixth resistor, a seventh resistor and a fifth capacitor connected in series,
one end of the sixth resistor is connected with one end of the fifth resistor,
one end of the seventh resistor is connected with the negative electrode of the power supply,
one end of the fifth capacitor is connected with one end of the sixth resistor and one end of the seventh resistor respectively,
the other end of the fifth capacitor is connected with one end of the first resistor.
In some embodiments, the ac loop feedback branch comprises a fourth resistor, a fifth resistor and a fourth capacitor,
the fourth resistor is connected in series with the fifth resistor, the fourth capacitor is connected in parallel with the fourth resistor and the fifth resistor which are connected in series,
one end of the fourth resistor is connected with the output end of the operational amplifier, the other end of the fourth resistor and one end of the fifth resistor are respectively connected with the base electrode of the amplifier,
the other end of the fifth resistor and the emitter of the amplifier are connected with the base of the second triode.
In some embodiments, the first transistor is an NPN transistor,
the second triode is a PNP triode.
In some embodiments, the circuit further comprises a cross-loop feedback branch, the cross-loop feedback branch comprises a first capacitor, a second capacitor and a second resistor,
one end of the first capacitor is coupled to the non-inverting terminal of the operational amplifier,
the other end of the first capacitor is connected with one end of the second capacitor,
one end of the second resistor is connected with the other end of the second capacitor,
the other end of the second resistor is coupled to the output end of the operational amplifier.
Multiple negative feedback circuit in, including operational amplifier, first this level feedback branch road, output circuit, direct current loop feedback branch road and interchange loop feedback branch road, wherein, the signal of telecommunication of external input is received to operational amplifier's homophase end to carry out the gain to the signal of telecommunication, first this level feedback branch road, direct current loop feedback branch road and interchange loop feedback branch road feed back the signal of telecommunication of operational amplifier output to its inverting terminal respectively, with whole gain and the distortion that reduces operational amplifier. Compared with the prior art, the gain stability and the pass band broadening of the operational amplifier can be improved on one hand by adopting multiple voltage negative feedback and current negative feedback; on the other hand, negative feedback is introduced to control the amplitude of the input AC signal so as to avoid distortion of the signal waveform.
Drawings
The invention will be further explained with reference to the drawings and examples, wherein:
fig. 1 is a schematic circuit diagram of an embodiment of the multiple negative feedback circuit provided by the present invention.
Detailed Description
In order to clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
As shown in fig. 1, in the first embodiment of the multiple negative feedback circuit of the present invention, the multiple negative feedback circuit 100 includes an operational amplifier a101, a first current stage feedback branch 101, a dc loop feedback branch 102, an ac loop feedback branch 105, and an output circuit 107.
Specifically, the operational amplifier a101 may amplify by increasing or decreasing the analog input signal, and may perform operations such as addition and subtraction and calculus, which have a high-gain amplification effect.
The feedback circuit is configured to feed back a part or all of an electric signal (a voltage signal or a current signal) output from the operational amplifier a101 to an input terminal of the operational amplifier a101 to compare (add or subtract) the input signal with the input signal, and to control an output using a valid input signal obtained by the comparison.
Further, the non-inverting terminal (corresponding to the 2-pin) of the operational amplifier a101 receives an electrical signal (corresponding to a voltage signal or a current signal) Input by an external circuit (corresponding to Input), performs gain on the electrical signal, and then outputs the electrical signal to the amplifier VT103, the first current-stage feedback branch 101, the ac loop feedback branch 102, and the output circuit 107.
One end of the output circuit 107 is connected to the output end of the operational amplifier a101, and is configured to obtain a path of electric signal gained by the operational amplifier a101 and amplify the path of electric signal;
the amplifier VT103, wherein the amplifier VT103 in the present case mainly acts as a bias.
Further, an input terminal (corresponding to a base terminal) of the amplifier VT103 is connected to an output terminal of the operational amplifier a101, and an output terminal of the operational amplifier a101 is coupled to an output terminal of the output circuit 107.
Wherein, the amplifier VT103 is provided with a second current-stage feedback branch and a third current-stage feedback branch,
the second current-stage feedback branch has the function of dynamic bias;
the third present-stage feedback branch has the function of static bias.
The input end of the third current-stage feedback branch is connected with the output end of the operational amplifier A101;
the input end of the second current-stage feedback branch circuit is connected with the output end of the third current-stage feedback branch circuit,
the output end of the second present-stage feedback branch is coupled to the inverting end (corresponding to pin 3) of the operational amplifier a 101.
It should be noted that the second feedback branch includes a fourth capacitor C104, and a fourth resistor R104 and a fifth resistor R105 connected in series, where a connection end of the fourth resistor R104 and the fifth resistor R105 is connected to an input end of the amplifier VT103, so as to perform a static bias function on the amplifier VT 103.
The third feedback branch comprises a sixth resistor R106, a seventh resistor R107 and a fifth capacitor C105 which are connected in series, and plays a role of dynamically biasing the amplifier VT 103.
Furthermore, one end of the first local feedback branch 101 is connected to the output end (corresponding to 4 pins) of the operational amplifier a101, and is configured to obtain another electric signal gained by the operational amplifier a101, the other end of the first local feedback branch 101 is connected to the inverting end (corresponding to 3 pins) of the operational amplifier a101, and the first local feedback branch 101 feeds back the electric signal to the inverting end of the operational amplifier a101, introduces voltage negative feedback, and can stabilize the output signal voltage of the operational amplifier a101, so as to reduce the output impedance of the feedback circuit.
It should be noted that the feedback signal acquisition point of the first current-stage feedback branch 101 is at the output end of the operational amplifier a101, and therefore, the first current-stage feedback branch 101 is a voltage feedback loop.
Further, one end of the output circuit 107 is connected to the output end of the operational amplifier a101, and is configured to obtain another electric signal gained by the operational amplifier a101, amplify the another electric signal, and output a part or all of the amplified electric signal to the dc loop feedback branch 102 and the ac loop feedback branch 105 at an output node of the output circuit 107.
One end of the dc loop feedback branch 102 is connected to the output end of the output circuit 107, and is configured to obtain another electrical signal amplified by the output circuit 107, the other end of the dc loop feedback branch 102 is coupled to the inverting terminal (corresponding to 3 pins) of the operational amplifier a101, the dc loop feedback branch 102 feeds back the another electrical signal to the inverting terminal (corresponding to 3 pins) of the operational amplifier a101, and the dc signal fed back by the dc loop feedback branch 102 is used to stabilize the dc operating state (or stabilize the static operating point) of the operational amplifier a101, so as to improve the stability of the gain of the operational amplifier a101 and the pass band broadening.
Note that the feedback signal acquisition point of the dc loop feedback branch 102 is at the output node of the output circuit 107, and the dc loop feedback branch 102 has no bypass capacitor, so the dc loop feedback branch 102 is a dc feedback loop.
Further, one end of the ac loop feedback branch 105 is connected to the output end of the output circuit 107, and is configured to obtain another electric signal after being gained by the operational amplifier a101, the other end of the ac loop feedback branch 105 is connected to the inverting terminal (corresponding to 3 pins) of the operational amplifier a101, and the ac loop feedback branch 105 feeds back the another electric signal to the inverting terminal (corresponding to 3 pins) of the operational amplifier a 101.
Specifically, the amplitude of the input ac signal is limited or weakened by the ac loop feedback branch 105 to avoid the operational amplifier a101 entering a saturation or cutoff state, so that the output signal is distorted by clipping, and the amplitude of the input ac signal is controlled by introducing an ac negative feedback, so as to avoid the distortion.
The first current-stage feedback branch 101, the dc-loop feedback branch 102 and the ac-loop feedback branch 105 feed back the electric signals (voltage signal, dc signal and ac signal) to reduce the overall gain and distortion of the operational amplifier a 101.
In the technical scheme, on one hand, the three-stage feedback branch is used for expanding wider effective working bandwidth and introducing negative feedback to control the amplitude of an input alternating current signal so as to avoid distortion of a signal waveform; on the other hand, the net input signal of the basic operational amplifier a101 is changed in the increasing direction, thereby compensating for the tendency that it originally decreases with the increase in frequency, preventing the output signal from decreasing, and expanding the frequency response.
In some embodiments, in order to improve the stability of the negative feedback signal, a third capacitor C103 may be disposed in the first current stage feedback branch 101, and serves as a feedback capacitor, and functions to block ac and dc.
Specifically, one end of the third capacitor C103 is connected to the output end (corresponding to 4 pins) of the operational amplifier a101, and the other end of the third capacitor C103 is connected to the inverting end (corresponding to 3 pins) of the operational amplifier a 101.
The voltage signal output by the operational amplifier a101 is fed back to the inverting terminal (corresponding to pin 3) of the operational amplifier a101 through the third capacitor C103, and the third capacitor C103 introduces voltage negative feedback, so that the voltage of the output signal of the operational amplifier a101 can be stabilized, and the output impedance of the feedback circuit can be reduced.
In some embodiments, in order to increase the current amplification factor of the output signal, a first transistor VT101 and a second transistor VT102 may be disposed in the output circuit 107, wherein the first transistor VT101 is an NPN transistor, and the second transistor VT102 is a PNP transistor, which has switching and amplifying functions.
Specifically, the bases of the first transistor VT101 and the second transistor VT102 are respectively connected to the output terminal (corresponding to 4 pins) of the operational amplifier a101, wherein the base of the second transistor VT102 is connected to the output terminal (corresponding to 4 pins) of the operational amplifier a101 through the fourth capacitor C104.
The first transistor VT101 and the second transistor VT102 respectively receive the electric signals after being gained by the operational amplifier a 101.
Further, the emitter of the first transistor VT101 is connected to the emitter of the second transistor VT102 through an eighth resistor R108 and a ninth resistor R109 connected in series, wherein a connection point of the eighth resistor R108 and the ninth resistor R109 serves as an output terminal of the output circuit 107.
The collector of the first transistor VT101 is connected to the positive power supply (VCC), and the collector of the second transistor VT102 is connected to the negative power supply (VEE).
Specifically, when the electrical signal (bias voltage) input to the base of the first transistor VT101 by the operational amplifier a101 is greater than 0.7V, a forward voltage is applied to the collector of the first transistor VT101, at this time, the first transistor VT101 is triggered and turned on, the electrical signal (voltage or current signal) Output by the operational amplifier a101 after gain flows through the eighth resistor R108, and then is divided into two branches to be Output, one branch is fed back to the ac loop feedback branch 105, and then is input to the inverting terminal (corresponding to pin 3) of the operational amplifier a101, and the other branch is Output (corresponding to Output) through the tenth resistor R110 and the first inductor L101 which are connected in parallel.
The first inductor L101 serves as a shunt element, and has functions of screening signals, filtering noise, and stabilizing current.
In some embodiments, in order to improve the dc operating state of the operational amplifier a101, a first resistor R101 may be disposed in the dc loop feedback branch 102, wherein the first resistor R101 is a dc degeneration resistor.
Specifically, one end of the first resistor R101 is connected to the emitter of the first transistor VT101 and the emitter of the second transistor VT102, specifically, one end of the first resistor R101 is connected to the connection ends of the eighth resistor R108 and the ninth resistor R109, respectively, and is configured to obtain an electrical signal flowing through the eighth resistor R108.
The other end of the first resistor R101 is connected to the inverting terminal (corresponding to pin 3) of the operational amplifier a101, and the obtained electrical signal is input to the inverting terminal (corresponding to pin 3) of the operational amplifier a101, so as to weaken the input current and stabilize the dc operating state of the operational amplifier a 101.
Of course, if the dc operation of the operational amplifier a101 is stabilized, the ac operation state thereof is stabilized, so the primary purpose of the dc negative feedback is to stabilize the ac operation state of the operational amplifier a 101.
In some embodiments, in order to improve the performance of the feedback circuit, an ac loop feedback branch 102 may be provided in the circuit, and specifically, an input end of the ac loop feedback branch 102 is connected to an output end (corresponding to 4 pins) of the operational amplifier a101, and an output end of the ac loop feedback branch 102 is connected to an output end of the output circuit 107.
Further, the ac loop feedback branch 102 includes a fourth capacitor C104, a fourth resistor R104, a fifth resistor R105, and an amplifier VT103, wherein the amplifier VT103 is an NPN-type transistor and has a signal amplification function.
It should be noted that the ac loop feedback branch 102 has a static bias function in this embodiment.
Specifically, the fourth resistor R104 is connected in series with the fifth resistor R105, wherein the fourth capacitor C104 is connected in parallel with the series connection of the fourth resistor R104 and the fifth resistor R105.
One end of the fourth resistor R104 is connected to the output end (corresponding to 4 pins) of the operational amplifier a101, the other end of the fourth resistor R104 and one end of the fifth resistor R105 are respectively connected to the base of the amplifier VT103, and the other end of the fifth resistor R105 and the emitter of the amplifier VT103 are connected to the base of the second transistor VT 102.
In some embodiments, in order to improve the stability of the ac loop feedback branch 102, a sixth resistor R106 and a seventh resistor R107 may be disposed in the circuit, wherein the sixth resistor R106 and the seventh resistor R107 are connected in series.
Specifically, one end of the sixth resistor R106 is connected to one end of the fifth resistor R105, and one end of the seventh resistor R107 is connected to the negative electrode (corresponding to VEE) of the power supply.
In some embodiments, in order to reduce the distortion of the feedback signal, a cross-loop feedback branch (formed by connecting the first current-stage feedback branch 101, the feedback branch 103, and the feedback branch 104) may be provided in the circuit.
A second resistor R102 and a second capacitor C102 are disposed in the cross-loop feedback branch, wherein the second resistor R102 is an ac feedback resistor, and the second capacitor C102 is a feedback capacitor.
The second resistor R102 is used to control the magnitude of the negative feedback quantity, and the smaller the resistance value is, the smaller the ac negative feedback quantity of the operational amplifier a101 is, the larger the closed-loop amplification factor of the operational amplifier a101 is, and vice versa.
The second capacitor C102 functions as an ac blocking circuit for preventing the dc component from passing through, so as to obtain strong ac negative feedback to stabilize the ac operating state of the operational amplifier a 101.
Specifically, one end of the first capacitor C101 is coupled to the non-inverting terminal of the operational amplifier a101, and the other end of the first capacitor C101 is connected to one end of the second capacitor C102.
One end of the second resistor R102 is connected to the other end of the second capacitor C102, and the other end of the second resistor R102 is coupled to the output end of the operational amplifier a 101.
Two ends of the second resistor R102 are respectively connected to the emitter of the first transistor VT101 and the emitter of the second transistor VT102, specifically, one end of the second resistor R102 is respectively connected to the connection ends of the eighth resistor R108 and the ninth resistor R109, and is configured to obtain an electrical signal flowing through the eighth resistor R108.
The other end of the second resistor R102 is connected to one end of the second capacitor C102, and the other end of the second capacitor C102 is coupled to the inverting terminal (corresponding to pin 3) of the operational amplifier a 101. One end of the second capacitor C102 is connected to the common terminal through the third resistor R103.
The second resistor R102 and the second capacitor C102 input the obtained electrical signal to the inverting terminal (corresponding to 3 pins) of the operational amplifier a101, so as to weaken the input current, thereby improving the ac operating state of the operational amplifier a101, improving the quality of the output signal of the operational amplifier a101, further limiting the operating frequency band, and reducing the distortion.
In the technical scheme, a plurality of nodes are electrically connected to the signal input end of the operational amplifier A101, and each node respectively realizes direct current feedback and alternating current feedback, so that triple feedback is realized, and the operational amplifier A101 has the following effects:
on one hand, the three-level feedback branch is used for expanding wider bandwidth and reducing signal distortion;
on the other hand, the net input signal of the operational amplifier A101 is changed towards the increasing direction, so that the original trend of descending along with the frequency rising is compensated, the output signal is prevented from being reduced, and the frequency response is expanded.
The embodiments of the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the above-mentioned embodiments, which are only illustrative and not restrictive, and those skilled in the art can make many forms without departing from the spirit and scope of the present invention, which is within the protection scope of the present invention.
Claims (9)
1. A multiple negative feedback circuit is provided with:
the operational amplifier receives an externally input electric signal at a non-inverting end thereof and gains the electric signal;
one end of the output circuit is connected with the output end of the operational amplifier and is used for acquiring one path of electric signals gained by the operational amplifier and amplifying one path of electric signals;
the input end of the amplifier is connected with the output end of the operational amplifier, and the output end of the operational amplifier is coupled with the output end of the output circuit;
a first local feedback branch, one end of which is connected to the output end of the operational amplifier and is used for obtaining another path of electric signal gained by the operational amplifier, and the other end of which is coupled to the inverting end of the operational amplifier, wherein the first local feedback branch feeds back the other path of electric signal to the inverting end of the operational amplifier;
one end of the direct current loop feedback branch is connected with the output end of the output circuit and used for acquiring the other path of the electric signal amplified by the output circuit, the other end of the direct current loop feedback branch is coupled with the inverting end of the operational amplifier, and the direct current loop feedback branch feeds the other path of the electric signal back to the inverting end of the operational amplifier;
one end of the alternating current loop feedback branch is connected with the output end of the output circuit and used for acquiring another path of electric signal gained by the operational amplifier, the other end of the alternating current loop feedback branch is coupled with the inverting end of the operational amplifier, and the other path of electric signal is fed back to the inverting end of the operational amplifier by the alternating current loop feedback branch;
and the overall gain and distortion of the operational amplifier are reduced through the electric signals fed back by the first current-stage feedback branch, the direct current loop feedback branch and the alternating current loop feedback branch.
2. The multiple negative feedback circuit of claim 1,
the first current-stage feedback branch comprises a third capacitor, one end of the third capacitor is connected with the output end of the operational amplifier,
the other end of the third capacitor is coupled to the inverting terminal of the operational amplifier.
3. The multiple negative feedback circuit of claim 1,
the amplifier is provided with a second current-stage feedback branch and a third current-stage feedback branch,
the input end of the third current-stage feedback branch circuit is connected with the output end of the operational amplifier;
the input end of the second current-stage feedback branch circuit is connected with the output end of the third current-stage feedback branch circuit,
the output end of the second current-stage feedback branch is coupled to the inverting end of the operational amplifier.
4. The multiple negative feedback circuit of claim 1,
the output circuit comprises a first triode and a second triode,
the base electrodes of the first triode and the second triode are respectively connected with the output end of the operational amplifier,
the emitter of the first triode is connected with the emitter of the second triode,
the collector of the first triode is connected with the positive electrode of the power supply,
and the collector of the second triode is connected with the negative electrode of the power supply.
5. The multiple negative feedback circuit of claim 4,
the direct current loop feedback branch circuit comprises a first resistor, one end of the first resistor is respectively connected with the emitter of the first triode and the emitter of the second triode,
the other end of the first resistor is coupled to the inverting terminal of the operational amplifier.
6. The multiple negative feedback circuit of claim 5,
the direct current loop feedback branch circuit also comprises a sixth resistor, a seventh resistor and a fifth capacitor which are connected in series,
one end of the sixth resistor is connected with one end of the fifth resistor,
one end of the seventh resistor is connected with the negative electrode of the power supply,
one end of the fifth capacitor is connected with one end of the sixth resistor and one end of the seventh resistor respectively,
the other end of the fifth capacitor is connected with one end of the first resistor.
7. The multiple negative feedback circuit of claim 6,
the alternating current loop feedback branch circuit comprises a fourth resistor, a fifth resistor and a fourth capacitor,
the fourth resistor is connected in series with the fifth resistor, the fourth capacitor is connected in parallel with the fourth resistor and the fifth resistor which are connected in series,
one end of the fourth resistor is connected with the output end of the operational amplifier, the other end of the fourth resistor and one end of the fifth resistor are respectively connected with the base electrode of the amplifier,
the other end of the fifth resistor and the emitter of the amplifier are connected with the base of the second triode.
8. The multiple negative feedback circuit of claim 5 or 6,
the first triode is an NPN type triode,
the second triode is a PNP triode.
9. The multiple negative feedback circuit of claim 1,
the circuit also comprises a cross loop feedback branch circuit, the cross loop feedback branch circuit comprises a first capacitor, a second capacitor and a second resistor,
one end of the first capacitor is coupled to the non-inverting terminal of the operational amplifier,
the other end of the first capacitor is connected with one end of the second capacitor,
one end of the second resistor is connected with the other end of the second capacitor,
the other end of the second resistor is coupled to the output end of the operational amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120540759.4U CN214959454U (en) | 2021-03-16 | 2021-03-16 | Multiple negative feedback circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120540759.4U CN214959454U (en) | 2021-03-16 | 2021-03-16 | Multiple negative feedback circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN214959454U true CN214959454U (en) | 2021-11-30 |
Family
ID=79040609
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202120540759.4U Active CN214959454U (en) | 2021-03-16 | 2021-03-16 | Multiple negative feedback circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN214959454U (en) |
-
2021
- 2021-03-16 CN CN202120540759.4U patent/CN214959454U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4589665B2 (en) | Amplifier and high-frequency power amplifier using the same | |
| US7843263B2 (en) | Power amplifier with noise shaping function | |
| JP2010124433A (en) | High-frequency power amplifier | |
| US7719361B2 (en) | Differential amplifier with current source controlled through differential feedback | |
| CN211149306U (en) | Low-noise wide-bandwidth L DO circuit structure | |
| CN104348431B (en) | Common-mode feedback differential amplification circuit, method and integrated circuit | |
| CN214959454U (en) | Multiple negative feedback circuit | |
| CN203457116U (en) | CMFB differential amplification circuit and integrated circuit | |
| DE102013109957B4 (en) | Circuit for preventing load-induced non-linearity in operational amplifiers | |
| CN116232241B (en) | Instrument amplifying circuit and current monitor | |
| CN112953410A (en) | Multiple negative feedback circuit | |
| CN110557098A (en) | positive feedback transimpedance amplification circuit and adjustment method | |
| CN116404993A (en) | DC offset eliminating circuit and driving chip | |
| US4739280A (en) | Amplifier circuit having reduced crossover distortion | |
| US11444587B2 (en) | Multiple feedback filter | |
| CN210183292U (en) | Follower circuit structure with built-in negative feedback | |
| EP0410536B1 (en) | Combined current differencing and operational amplifier circuit | |
| KR20220082048A (en) | Digital Audio Power Amplifiers and Power Amplifier Loops | |
| US9065408B2 (en) | Voltage controlled amplifier and method of using the same | |
| CN218416350U (en) | Circuit for converting double-end signal into single-end signal | |
| JPS5840370B2 (en) | Zoufuku Cairo | |
| CN108123688A (en) | For the promotion circuit of power amplifier | |
| KR20130061614A (en) | Power amplifier | |
| JP2737718B2 (en) | Optical receiving circuit | |
| CN215912030U (en) | Practical pre-load circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |