CN220121244U - Analog multiplier - Google Patents

Abstract

The utility model relates to the technical field of circuits, in particular to an analog multiplier, which comprises a current-voltage conversion module, an amplifying module and a voltage-current conversion module; the current-voltage conversion module comprises a first triode, a second triode and a third triode, converts input current into input voltage and sends the input voltage to the amplification module, and the amplification module comprises a feedback unit, an amplifier and a feedback triode and is used for amplifying the input voltage and sending the amplified input voltage to the voltage-current conversion module; the voltage-current conversion module is composed of a first field effect transistor, converts the received amplified voltage into a current signal and sends the current signal to a later stage load, and the later stage load is set through a current mirror load formed by mirror connection of two field effect transistors and is used for receiving and adjusting the current signal and outputting a current mirror; the multiplier is compatible with the CMOS process by adjusting the circuit design, has stronger large-signal processing capacity, and can also consider the overall cost on the premise of keeping stable signal transmission.

Description

Analog multiplier

Technical Field

The utility model relates to the technical field of circuits, in particular to an analog multiplier.

Background

In modern electronic systems, multipliers are very important functional modules, and are widely used in the fields of digital signal processing, mixing, power detection, etc.; the prior art multiplier is based on a transconductance linear circuit (translinear circuit) of a triode (bipolar) which can convert an input signal into an output current, the output current of the transconductance linear circuit is proportional to the product of the input voltage, the output current of the transconductance linear circuit is not affected by a voltage source, and the multiplier has the capability of processing a large signal, but the transconductance linear circuit based on the triode is not compatible with a low-cost CMOS (complementary metal oxide semiconductor) process, so the requirement of low-cost application cannot be met.

It can be seen that the prior art multipliers have the problem that they do not meet both the capability of processing large signals and compatibility with low cost cmos processes.

Disclosure of Invention

The utility model aims to overcome the defects of the prior art, provides an analog multiplier, and aims to solve the problems of insufficient large signal processing capacity and high use cost of the prior multiplier.

The aim of the utility model is realized by the following technical scheme: an analog multiplier comprises a current-voltage conversion module, an amplifying module and a voltage-current conversion module;

the input end of the current-voltage conversion module is used for receiving a first input current, a second input current and a current source current, the output end of the current-voltage conversion module is connected with the amplifying module and is used for converting a first input voltage, a second input voltage and a third input voltage according to the received first input current, the received second input current and the received current source current, and the current-voltage conversion module is also used for sending the first input voltage, the received second input voltage and the received third input voltage to the amplifying module;

the amplifying module is connected with the current-voltage conversion module and is used for amplifying and outputting a target amplified voltage according to the received first input voltage, the second output voltage and the third input voltage sent by the current-voltage conversion module and sending the target amplified voltage to the voltage-current conversion module;

the voltage-current conversion module is connected with an external post-stage load and used for converting the received target amplified voltage into target current and sending the target current to the target post-stage load.

Preferably, the amplifying module includes: the feedback unit, the amplifier and the feedback triode; the feedback unit includes: the input end is connected with the current-voltage conversion module and is used for receiving the first input voltage, the second input voltage and the third input voltage, converting the first input voltage and the second input voltage into first output voltage and converting the third input voltage into second output voltage; the non-inverting input end and the inverting input end of the amplifier are respectively connected with the output end of the feedback unit, the output end of the amplifier is connected with the voltage-current conversion module, the non-inverting input end of the amplifier is used for receiving the first output voltage, the inverting input end of the amplifier is used for receiving the second output voltage, and the amplifier is used for outputting target amplified voltage according to the first output voltage and the second output voltage; the emitter of the feedback triode is respectively connected with the voltage-current conversion module and the feedback input end of the feedback unit, the base electrode and the collector electrode of the feedback triode are grounded and used for sending target amplified voltage to the feedback unit, so that the feedback unit regulates the inverting input end of the amplifier.

Preferably, the current-voltage conversion module includes: the first triode, the second triode and the third triode; the base electrode of the first triode is grounded, the collector electrode of the first triode is grounded, and the emitter electrode of the first triode is connected with the first input end of the feedback unit; the base electrode of the second triode is grounded, the collector electrode of the first triode is grounded, and the emitter electrode of the first triode is connected with the second input end of the feedback unit; the base electrode of the third triode is grounded, the collector electrode of the third triode is grounded, and the emitter electrode of the first triode is connected with the third input end of the feedback unit.

Preferably, the feedback unit includes: a resistor network.

Preferably, the resistor network comprises: a first resistor, a second resistor, a third resistor and a fourth resistor; the first end of the first resistor is connected with the first output end of the current-voltage conversion module, and the second end of the first resistor is connected with the non-inverting input end of the amplifier; the first end of the second resistor is connected with the second output end of the current-voltage conversion module, and the second end of the second resistor is connected with the non-inverting input end of the amplifier; the first end of the third resistor is connected with the third output end of the current-voltage conversion module, and the second end of the third resistor is connected with the inverting input end of the amplifier; the first end of the fourth resistor is connected with the inverting input end of the amplifier, and the second end of the fourth resistor is connected with the emitter of the feedback triode.

Preferably, the feedback unit includes: a switched capacitor network.

Preferably, the switched capacitor network comprises: a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a first capacitor and a second capacitor; the first end of the first switch is connected with the first output end of the current-voltage conversion module, the second end of the first switch is connected with the first end of the first capacitor, and the second end of the first capacitor is connected with the first end of the fourth switch and then is also connected with the non-inverting input end of the amplifier; the first end of the second switch is connected with the second output end of the current-voltage conversion module, and the second end of the second switch is connected with the first end of the second capacitor and then is also connected with the first end of the fifth switch; the second end of the second capacitor is connected with the first end of the sixth switch and then is also connected with the inverting input end of the amplifier; the second end of the fifth switch is connected with the second end of the sixth switch together and then connected with the emitter of the feedback triode; the first end of the third switch is connected with the third output end of the current-voltage conversion module, and the second end of the third switch is connected with the first end of the first capacitor.

Preferably, the amplifier is a chopper amplifier or a zeroing amplifier.

Preferably, the voltage-current conversion module includes: a first field effect transistor; the grid electrode of the first field effect tube is connected with the output end of the amplifier, the source electrode of the first field effect tube is connected with the emitter electrode of the feedback triode, and the drain electrode of the first field effect tube is connected with the rear-stage load and used for converting amplified voltage sent by the amplifier into current and sending the current to the rear-stage load for output.

The utility model also provides a rear-stage load, which comprises a current receiving unit, wherein the current receiving unit comprises: the second field effect transistor and the third field effect transistor; the grid electrode of the second field effect tube is respectively connected with the drain electrode and the grid electrode of the third field effect tube, the source electrode of the second field effect tube is respectively connected with the anode of an external power supply and the source electrode of the third field effect tube, and the drain electrode of the second field effect tube is connected with the output end of the voltage-current conversion module; the drain electrode of the third field effect transistor is used as a current output end for providing electric energy for a subsequent load.

The beneficial effects of the utility model are as follows: the current-voltage conversion module performs current-voltage conversion on an input current signal and outputs a corresponding signal to the amplification module, the amplification module amplifies and feeds back and adjusts the voltage, noise and errors in a transmission signal can be greatly reduced, the voltage-current module converts the amplified voltage to a later-stage load, and the characteristics of high input impedance and low output impedance of the voltage-current module can further improve the large signal processing capacity of the multiplier and keep the accuracy and stability of signal transmission; in summary, the analog multiplier provided by the utility model has high signal processing capability and is compatible with a low-cost CMOS (complementary metal oxide semiconductor) process while ensuring signal transmission precision, so that the analog multiplier can be widely used in practical application.

Drawings

FIG. 1 is a schematic diagram of an analog multiplier according to an embodiment of the present utility model;

FIG. 2 is a circuit diagram of an analog multiplier provided in an embodiment of the present utility model;

fig. 3 is a circuit diagram of a resistor network and a current receiving unit provided in an embodiment of the present utility model;

FIG. 4 is a circuit diagram of a switched capacitor network provided in an embodiment of the present utility model;

fig. 5 is a schematic diagram of a switch control signal of a switched capacitor network according to an embodiment of the present utility model.

Detailed Description

The technical solution of the present utility model will be described in further detail with reference to the accompanying drawings, but the scope of the present utility model is not limited to the following description.

For the purpose of making the technical solution and advantages of the present utility model more apparent, the present utility model will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the particular embodiments described herein are illustrative only and are not intended to limit the utility model, i.e., the embodiments described are merely some, but not all, of the embodiments of the utility model. The components of the embodiments of the present utility model generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the utility model, as presented in the figures, is not intended to limit the scope of the utility model, as claimed, but is merely representative of selected embodiments of the utility model. All other embodiments, which can be made by a person skilled in the art without making any inventive effort, are intended to be within the scope of the present utility model. It is noted that relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises the element.

The features and capabilities of the present utility model are described in further detail below in connection with the examples.

Example 1

Fig. 1 is a schematic circuit diagram of an analog multiplier according to an embodiment of the present utility model, as shown in fig. 1, the analog multiplier includes a current-to-voltage conversion module 100, an amplifying module 200, and a voltage-to-current conversion module 300;

the input end of the current-voltage conversion module 100 is used for receiving a first input current, a second input current and a current source current, the output end of the current-voltage conversion module 100 is connected with the amplifying module and is used for converting a first input voltage, a second input voltage and a third input voltage according to the received first input current, the received second input current and the received current source current, and is also used for sending the first input voltage, the received second input voltage and the received third input voltage to the amplifying module;

the amplifying module 200 is connected to the current-voltage converting module 100, and is configured to amplify and output a target amplified voltage according to the received first input voltage, the second output voltage, and the third input voltage sent by the current-voltage converting module 100, and send the target amplified voltage to the voltage-current converting module 300;

the voltage-current conversion module 300 is connected to the external post-stage load 400, and is configured to convert the received target amplified voltage into a target current and send the target current to the target post-stage load 400.

The working principle of the embodiment is as follows: the current-voltage conversion module 100 respectively converts the input three paths of current signals into voltage signals and outputs the voltage signals, the amplifying module 200 amplifies and feeds back the voltage signals to be regulated and sends the voltage signals to the voltage-current conversion module 300, the voltage-current conversion module 300 converts the received amplified voltage into current signals and transmits the current signals to the rear-stage load 400, and the rear-stage load 400 controls the magnitude of output current so that the current can be converted into the expected voltage or the current magnitude to be output to the next-stage circuit, and the accuracy and the stability of signal transmission are ensured.

Example two

FIG. 2 is a circuit diagram of an analog multiplier provided in an embodiment of the present utility model; as shown in fig. 2, the amplifying module 200 includes: a feedback unit 500, an amplifier U1 and a feedback transistor Q4;

the feedback unit 500 includes: the input end is connected with the current-voltage conversion module 100 and is used for receiving the first input voltage, the second input voltage and the third input voltage, converting the first input voltage and the second input voltage into a first output voltage according to the first input voltage and the second input voltage and converting the third input voltage into a second output voltage; the non-inverting input end and the inverting input end of the amplifier U1 are respectively connected with the output end of the feedback unit 200, the output end of the amplifier U1 is connected with the voltage-current conversion module 300, the non-inverting input end of the amplifier U1 is used for receiving the first output voltage, the inverting input end of the amplifier U1 is used for receiving the second output voltage, and the amplifier U1 is used for outputting a target amplified voltage according to the first output voltage and the second output voltage; the emitter of the feedback triode Q4 is connected to the feedback input ends of the voltage-current conversion module 300 and the feedback unit 500, and the base and collector of the feedback triode Q4 are grounded, so that the target amplified voltage is sent to the feedback unit 200, and the feedback unit 200 adjusts the inverting input end of the amplifier U1.

The current-voltage conversion module 100 includes: a first transistor Q1, a second transistor Q2, and a third transistor Q3; the base electrode of the first triode Q1 is grounded, the collector electrode of the first triode Q1 is grounded, and the emitter electrode of the first triode Q1 is connected with the first input end of the feedback unit 500; the base electrode of the second triode Q2 is grounded, the collector electrode of the second triode Q2 is grounded, and the emitter electrode of the second triode Q2 is connected with the second input end of the feedback unit 500; the base electrode of the third triode Q3 is grounded, the collector electrode of the third triode Q3 is grounded, and the emitter electrode of the third triode Q3 is connected with the third input end of the feedback unit 500.

The voltage-to-current conversion module 300 includes: a first field effect transistor M1; the grid electrode of the first field effect tube M1 is connected with the output end of the amplifier U1, the source electrode of the first field effect tube M1 is connected with the emitter electrode of the feedback triode Q4, and the drain electrode of the first field effect tube M1 is connected with the rear-stage load 400 and used for converting amplified voltage sent by the amplifier U1 into current and sending the current to the rear-stage load 400 for output.

The amplifier U1 is either a chopper amplifier or a zeroing amplifier.

It should be noted that, the current-voltage conversion module 100 selects three PNP transistors matched with each other, and may, but not limited to, select transistors with identical size designs to achieve the best matching effect; in a specific case, we select three transistors with identical dimensions, where emitters of the first transistor Q1, the second transistor Q2, and the third transistor Q3 are used as input terminals, and correspondingly receive two first input currents I1 and second input currents I2 that need to be multiplied and a constant current source current Ic, respectively, and convert the three input currents into vbe voltages of the transistors by using characteristics that vbe voltages and currents of the transistors are in an exponential relationship, and send the vbe voltages to the amplifying module 200, and the amplifying module 200 amplifies and feeds back a target voltage signal, optimizes transmission accuracy of the multiplier, and finally transmits the target voltage signal to the first field-effect transistor M1 to convert the voltage current and output the target current Io to the target post load 400.

In the feedback unit 500, the voltage at the first input of the feedback unit 500 is denoted by V1, where V1: the voltage at the second input end of the feedback unit 500 is represented by a first triode Q1, the voltage at the third input end of the feedback unit 500 is represented by V3, the voltage at the feedback input end of the feedback unit 500 is represented by V4, and the voltage at the first output end of the feedback unit 500 is represented by Vp; the voltage at the second output of the feedback unit 500 is denoted by Vn;

the feedback unit 500 receives the first input voltage, the second input voltage and the third input voltage converted by the current-voltage conversion module 100, and sends the first input voltage, the second input voltage and the third input voltage to the amplifier U1 through the non-inverting input end to amplify the signal, and the amplified signal is converted into voltage and current through the first field effect transistor M1; the emitter of the feedback triode Q4 receives the current Io output by the first field effect transistor M1, the output current Io is converted into feedback voltage by utilizing the characteristic of the relation between the voltage of the triode vbe and the current index and is sent to the feedback unit 500, the feedback triode Q4 feeds back a feedback voltage signal to the feedback unit 500 again, the feedback unit 500 regulates the amplifier U1, and the performance of the amplifier is influenced and optimized by reinjecting an input signal to the inverting input end of the amplifier U1;

the closed-loop control circuit consisting of the feedback unit 500, the amplifier U1, the feedback triode Q4 and the rear-stage load 500 ensures the precision and stability of the circuit, so that the two input voltages of the stabilized amplifier U1 are almost equal, and the larger the gain of the amplifier U1 is, the smaller the error of the two voltages is;

v1, V2, V3 and V4 are satisfied by the connection structure of the closed-loop control circuit:

v1+v2+vos=v3+v4 (formula 1)

Where Vos is the equivalent input offset voltage of amplifier U1,

in this embodiment, we choose the zeroing amplifier to set so that Vos is much smaller than V1, V2, V3, and V4, so that equation 1 can be approximated as:

v1+v2=v3+v4 (formula 2)

Meanwhile, four triodes with identical dimensions are selected, and according to the relation of the voltage of the emitter and the base of the triodes, the following formula 1 can be adopted:

i1.i2=ic.io (formula 3)

In equation 3, ic is a constant current source, I1 and I2 are two input current signals to be multiplied, and the output current Io is proportional to the product of the two input current signals.

Example III

Fig. 3 is a circuit diagram of a resistor network and a current receiving unit according to an embodiment of the present utility model, and as shown in fig. 3, the feedback unit 500 includes: a resistor network.

The resistor network includes: a first resistor R1, a second resistor R2, a third resistor R3 and a fourth resistor R4; a first end of the first resistor R1 is connected to a first output end of the current-voltage conversion module 100, and a second end of the first resistor R1 is connected to a non-inverting input end of the amplifier U1; the first end of the second resistor R2 is connected to the second output end of the current-voltage conversion module 100, and the second end of the second resistor R2 is connected to the non-inverting input end of the amplifier U1; the first end of the third resistor R3 is connected to the third output end of the current-voltage conversion module 100, and the second end of the third resistor R3 is connected to the inverting input end of the amplifier U1; the first end of the fourth resistor R4 is connected to the inverting input terminal of the amplifier U1, and the second end of the fourth resistor R4 is connected to the emitter of the feedback triode Q4.

A rear stage load 400 comprising a current receiving unit 400, the current receiving unit 400 comprising: a second field effect transistor M2 and a third field effect transistor M3; the grid electrode of the second field effect tube M2 is respectively connected with the drain electrode and the grid electrode of the third field effect tube M3, the source electrode of the second field effect tube M2 is respectively connected with the anode of an external power supply and the source electrode of the third field effect tube, and the drain electrode of the second field effect tube M2 is connected with the output end of the voltage-current conversion module 300; the drain electrode of the third field effect transistor M3 is used as a current output end for providing electric energy for the subsequent stage load.

It should be noted that the resistors in the resistor network may be used to control the gain and the frequency response of the feedback unit 500, so as to realize accurate adjustment of the performance of the amplifier, and in a specific case, we select 4 resistors with the same resistance and larger resistance: the resistors with larger resistance values are selected for setting to realize current feedback, so that the current flowing through the resistors is far smaller than I1, I2, ic and Io, namely, errors generated by the current flowing through the resistors can be ignored, and the stability and the precision of the circuit are improved;

the first field effect transistor M1 converts the amplified voltage output by the amplifier U1 into a current signal Io, the current signal Io is sent to the current receiving unit 400 for output, the current receiving unit 400 is a current mirror formed by mirror image connection of the second field effect transistor M2 and the third field effect transistor M3, the current mirror converts the received current signal Io into an output current Iout for mirror image output, the output current is controlled by setting the proportion of the second field effect transistor M2 and the third field effect transistor M3, the conversion of the input current is realized, the current can be converted into the expected voltage or current through the current mirror and is output to a next-stage circuit, the accuracy and the stability of signal transmission are maintained, and the flexible use of the next-stage circuit is facilitated.

Example IV

Fig. 4 is a circuit diagram of a switched capacitor network according to an embodiment of the present utility model, and as shown in fig. 4, a feedback unit includes: a switched capacitor network.

The switched capacitor network comprises: a first switch SW1, a second switch SW2, a third switch SW3, a fourth switch SW4, a fifth switch SW5, a sixth switch SW6, a first capacitor C1 and a second capacitor C2;

the first end of the first switch SW1 is connected to the first output end of the current-voltage conversion module 100, the second end of the first switch SW1 is connected to the first end of the first capacitor C1, and the second end of the first capacitor C1 is connected to the first end of the fourth switch SW4 and then is connected to the non-inverting input end of the amplifier U1; the first end of the second switch SW2 is connected to the second output end of the current-voltage conversion module 100, and the second end of the second switch SW2 is connected to the first end of the second capacitor C2 and then is further connected to the first end of the fifth switch SW 5; the second end of the second capacitor C2 is connected to the first end of the sixth switch SW6 and then further connected to the inverting input end of the amplifier U1; the second end of the fifth switch SW5 is connected with the second end of the sixth switch SW6 and then connected with the emitter of the feedback triode Q4; a first end of the third switch SW3 is connected to the third output end of the current-voltage conversion module 100, and a second end of the third switch SW3 is connected to the first end of the first capacitor C1.

Fig. 5 is a schematic diagram of a switch control signal of a switched capacitor network.

It should be noted that, the capacitor network is a switched capacitor type self-zeroing circuit, which is easy to realize self-zeroing, thus avoiding error caused by amplifier offset voltage, the switched capacitor is controlled by three switch control time sequences, and the control of switch opening and closing is realized by adjusting the high and low level states of the control signals; wherein,is a second switch SControl signals for W2 and third switch SW3, ">For the control signals of the first switch and the fifth switch SW5,/for the control signals of the first switch and the fifth switch SW5>Control signals for the fourth switch SW4 and the sixth switch SW 6;

when (when)When high, V3 is connected to the lower plate of the first capacitor C1, and V2 is connected to the lower plate of the second capacitor C2;

when (when)When high, the non-inverting input terminal of the amplifier U1 is connected to V1 or other bias voltage of suitable magnitude, the inverting input terminal of the amplifier U1 is connected to the second output terminal of the feedback unit 500, and thus the offset voltage of the amplifier U1 is collected onto the second capacitor C2;

when (when)After jumping to a low level, the non-inverting input end and the inverting input end of the amplifier U1 enter a suspension state at the same time;

thereafterThen jump to low level, turn off V2, V3;

thereafterJump to high level, V1 is connected to the lower electrode plate of the first capacitor C1, and V4 is connected to the lower electrode plate of the second capacitor C2;

the circuit can be obtained according to the principle of conservation of charge, and after the circuit is stabilized:

v4=v1+v2-V3 (formula 4)

The foregoing is merely a preferred embodiment of the utility model, and it is to be understood that the utility model is not limited to the form disclosed herein but is not to be construed as excluding other embodiments, but is capable of numerous other combinations, modifications and environments and is capable of modifications within the scope of the inventive concept, either as taught or as a matter of routine skill or knowledge in the relevant art. And that modifications and variations which do not depart from the spirit and scope of the utility model are intended to be within the scope of the appended claims.

Claims (10)

1. An analog multiplier is characterized by comprising a current-voltage conversion module, an amplifying module and a voltage-current conversion module;

the input end of the current-voltage conversion module is used for receiving a first input current, a second input current and a current source current, the output end of the current-voltage conversion module is connected with the amplifying module and is used for converting a first input voltage, a second input voltage and a third input voltage according to the received first input current, the received second input current and the received current source current, and the current-voltage conversion module is also used for sending the first input voltage, the received second input voltage and the received third input voltage to the amplifying module;

the amplifying module is connected with the current-voltage conversion module and is used for amplifying and outputting a target amplifying voltage according to the received first input voltage, the second output voltage and the third input voltage sent by the current-voltage conversion module, and sending the target amplifying voltage to the voltage-current conversion module;

the voltage-current conversion module is connected with an external post-stage load and is used for converting the received target amplified voltage into target current and sending the target current to the external post-stage load.

2. An analog multiplier according to claim 1, wherein said amplifying module comprises: the feedback unit, the amplifier and the feedback triode;

the feedback unit includes: the input end is connected with the current-voltage conversion module and is used for receiving the first input voltage, the second input voltage and the third input voltage, converting the first input voltage and the second input voltage into first output voltage according to the first input voltage and the second input voltage and converting the third input voltage into second output voltage;

the non-inverting input end and the inverting input end of the amplifier are respectively connected with the output end of the feedback unit, the output end of the amplifier is connected with the voltage-current conversion module, the non-inverting input end of the amplifier is used for receiving the first output voltage, the inverting input end of the amplifier is used for receiving the second output voltage, and the amplifier is used for outputting target amplified voltage according to the first output voltage and the second output voltage;

the emitter of the feedback triode is respectively connected with the voltage-current conversion module and the feedback input end of the feedback unit, and the base electrode and the collector electrode of the feedback triode are grounded and used for sending the target amplified voltage to the feedback unit so that the feedback unit can regulate the inverting input end of the amplifier.

3. An analog multiplier according to claim 2, wherein said current-to-voltage conversion module comprises: the first triode, the second triode and the third triode;

the base electrode of the first triode is grounded, the collector electrode of the first triode is grounded, and the emitter electrode of the first triode is connected with the first input end of the feedback unit;

the base electrode of the second triode is grounded, the collector electrode of the second triode is grounded, and the emitter electrode of the second triode is connected with the second input end of the feedback unit;

the base electrode of the third triode is grounded, the collector electrode of the third triode is grounded, and the emitter electrode of the third triode is connected with the third input end of the feedback unit.

4. An analog multiplier according to claim 2, wherein said feedback unit comprises: a resistor network.

5. An analog multiplier as claimed in claim 4, in which the resistor network comprises: a first resistor, a second resistor, a third resistor and a fourth resistor;

the first end of the first resistor is connected with the first output end of the current-voltage conversion module, and the second end of the first resistor is connected with the non-inverting input end of the amplifier;

the first end of the second resistor is connected with the second output end of the current-voltage conversion module, and the second end of the second resistor is connected with the non-inverting input end of the amplifier;

the first end of the third resistor is connected with the third output end of the current-voltage conversion module, and the second end of the third resistor is connected with the inverting input end of the amplifier;

the first end of the fourth resistor is connected with the inverting input end of the amplifier, and the second end of the fourth resistor is connected with the emitter of the feedback triode.

6. An analog multiplier according to claim 2, wherein said feedback unit comprises: a switched capacitor network.

7. An analog multiplier as claimed in claim 6, in which the switched capacitor network comprises: a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a first capacitor and a second capacitor;

the first end of the first switch is connected with the first output end of the current-voltage conversion module, the second end of the first switch is connected with the first end of the first capacitor, and the second end of the first capacitor is connected with the first end of the fourth switch and then is connected with the non-inverting input end of the amplifier;

the first end of the second switch is connected with the second output end of the current-voltage conversion module, and the second end of the second switch is connected with the first end of the second capacitor and then is also connected with the first end of the fifth switch; the second end of the second capacitor is connected with the first end of the sixth switch and then is also connected with the inverting input end of the amplifier; the second end of the fifth switch is connected with the second end of the sixth switch together and then connected with the emitter of the feedback triode;

the first end of the third switch is connected with the third output end of the current-voltage conversion module, and the second end of the third switch is connected with the first end of the first capacitor.

8. An analog multiplier according to claim 2, in which the amplifier is a chopper or zeroing amplifier.

9. An analog multiplier according to claim 2, wherein said voltage to current conversion module comprises: a first field effect transistor;

the grid electrode of the first field effect tube is connected with the output end of the amplifier, the source electrode of the first field effect tube is connected with the emitter electrode of the feedback triode, and the drain electrode of the first field effect tube is connected with the external post-stage load and used for converting amplified voltage sent by the amplifier into current and sending the current to the external post-stage load for output.

10. An analog multiplier according to claim 1, wherein said external post-load comprises a current receiving unit comprising: the second field effect transistor and the third field effect transistor;

the grid electrode of the second field effect tube is respectively connected with the drain electrode and the grid electrode of the third field effect tube, the source electrode of the second field effect tube is respectively connected with the anode of an external power supply and the source electrode of the third field effect tube, and the drain electrode of the second field effect tube is connected with the output end of the voltage-current conversion module;

and the drain electrode of the third field effect transistor is used as a current output end and is used for providing electric energy for the external post-stage load.