阅读说明：本技术 一种自归零电流型高精度可编程增益放大器及方法 (Self-zeroing current type high-precision programmable gain amplifier and method ) 是由 刘若曦 田泽 余立宁 邵刚 刘敏侠 于 2020-12-05 设计创作，主要内容包括：本发明涉及一种自归零电流型高精度可编程增益放大器及方法。本发明包括自动调零运放A1、调零运放A2和二级调零运放A3,自动调零运放A1的输出端接一级输出管P1,一级输出管P1的源端上拉转换电阻R2,漏端接可变电阻阵列R1,可变电阻阵列R1的可变量程端接自动调零运放A1的负输入端,满量程端接调零运放A2的负输入端和输出端,上拉转换电阻R2与一级输出管P1连接处为二级输入信号,接二级调零运放A3,二级调零运放A3的输出端分别接二级输出管P2和二级输出管P3的栅端,二级输出管P2的源端接上拉转换电阻R3,二级输出管P3的源端接上拉转换电阻Ros,二级输出管P2的漏端为输出端口。本发明可以将传感器输入信号精确按比例放大,并可对传感器零点进行调零,同时对输出信号的幅度进行控制。(The invention relates to a self-zeroing current type high-precision programmable gain amplifier and a method. The invention comprises an automatic zero-setting operational amplifier A1, a zero-setting operational amplifier A2 and a secondary zero-setting operational amplifier A3, wherein the output end of the automatic zero-setting operational amplifier A1 is connected with a primary output tube P1, the source end of the primary output tube P1 is connected with a pull-up conversion resistor R2, the drain end of the automatic zero-setting operational amplifier A3 is connected with a variable range end of a variable resistor array R1 is connected with the negative input end of the automatic zero-setting operational amplifier A1, the full range end of the automatic zero-setting operational amplifier is connected with the negative input end and the output end of the zero-setting operational amplifier A2, the connection position of the pull-up conversion resistor R2 and the primary output tube P1 is a secondary input signal and is connected with a secondary zero-setting operational amplifier A3, the output end of the secondary zero-setting operational amplifier A3 is respectively connected with the gate ends of a secondary output tube P2 and a secondary output tube P3, the pull-up conversion resistor R3 of the secondary source end of the output tube. The invention can amplify the input signal of the sensor accurately in proportion, zero-set the zero point of the sensor and control the amplitude of the output signal.)

1. A self-zeroing current type high-precision programmable gain amplifier is characterized in that: the amplifier comprises an auto-zero operational amplifier A1, a zero-setting operational amplifier A2 and a secondary zero-setting operational amplifier A3, wherein the output end of the auto-zero operational amplifier A1 is connected with a primary output tube P1, the source end of the primary output tube P1 is connected with a pull-up conversion resistor R2, the drain end of the auto-zero operational amplifier A is connected with a variable resistor array R1, the variable range end of the variable resistor array R1 is connected with the negative input end of the auto-zero operational amplifier A1, the full range end of the auto-zero operational amplifier A5966 is connected with the negative input end and the output end of the zero-setting operational amplifier A2, zero-setting current Izero flows in or out from the connection position of the primary output tube P1 and the resistor array R1, the connection position of the pull-up conversion resistor R2 and the primary output tube P1 is a secondary input signal and is connected with the secondary zero-setting operational amplifier A3, the output end of the secondary zero-setting operational amplifier A3 is respectively connected with the gate ends of a secondary output tube P2 and a secondary output tube P3, the pull, the junction of the secondary output tube P2 and the conversion resistor R3 is a junction point X, the junction of the secondary output tube P3 and the pull-up conversion resistor Ros is a point Y, the junction point X is connected to the negative input end of the secondary zeroing operational amplifier A3 and the source end of the ground pass tube N2, the drain end of the ground pass tube N2 is grounded, the gate end is connected to the drain end of the secondary output tube P3, and simultaneously, an overvoltage control current Iover is output from the drain end of the secondary output tube P3 and loaded to the gate end of the ground pass tube N1 and the gate end of the ground pass tube N2, the source end of the ground pass tube N1 is connected to the junction point Y, the drain end is grounded, the drain end of the secondary output tube P2 is an output port, and simultaneously, an undervoltage compensation current Iunder flows in from the output port.

2. The self-zeroing current mode high accuracy programmable gain amplifier of claim 1, wherein: the output port is connected with a conversion resistor R4, and the other end of the conversion resistor R4 is grounded.

3. A method of implementing a self-zeroing current mode high accuracy programmable gain amplifier of claim 1, characterized by: the method comprises the following steps:

1) converting the input voltage difference into current through a programmable resistor R1 by the input stage of an automatic zero-setting operational amplifier A1;

2) when the sensor conditioning circuit is applied, after the programmable resistor R1 is converted into current, zero adjustment current Izero is introduced to perform zero adjustment control on the differential voltage when the sensor is subjected to zero input;

3) at the output stage of the two-stage zero-setting operational amplifier A3, converting the previous-stage input voltage into current through a conversion resistor R3;

5) when the output voltage does not meet the minimum requirement, the input is raised through injecting current by the undervoltage compensation current Iunder;

6) when the output voltage is greater than the required voltage, outputting overvoltage control current Iover to inject into a conversion resistor Ros, opening a grounding passage pipe N1 and a grounding passage pipe N2, and discharging redundant current to the ground to ensure the satisfaction; and outputting voltage limitation.

4. The method of self-zeroing current mode high accuracy programmable gain amplifier of claim 3, characterized by: the zero point adjusting current Izero in the step 2) is realized by injecting current and drawing current.

5. The method of self-zeroing current mode high accuracy programmable gain amplifier of claim 4, characterized by: in the step 4), the sizes of the conversion resistor R3, the conversion resistor Ros and the secondary output tube P2 and the secondary output tube P3 are designed in proportion to ensure that the voltages VX and VY are always equal.

Technical Field

The invention relates to the fields of aviation, navigation, aerospace and the like, in particular to a self-zeroing current type high-precision programmable gain amplifier and a method.

Background

The existing gain amplifier adopts an instrumentation amplifier with a three-operational amplifier structure, is in a voltage mode, and has the disadvantages that in the practical application process, the voltage is parasitic in the long-distance transmission process, the precision error caused by the long-distance transmission can seriously affect the precision of signal amplification, and the determination of poor expansibility exists.

Disclosure of Invention

The present invention provides a self-zeroing current type high-precision programmable gain amplifier and method for solving the above-mentioned technical problems in the background art, which can amplify the input signal of the sensor accurately in proportion, zero-adjust the zero point of the sensor, and control the amplitude of the output signal.

The technical solution of the invention is as follows: the invention relates to a self-zeroing current type high-precision programmable gain amplifier, which is characterized in that: the amplifier comprises an auto-zero operational amplifier A1, a zero-setting operational amplifier A2 and a secondary zero-setting operational amplifier A3, wherein the output end of the auto-zero operational amplifier A1 is connected with a primary output tube P1, the source end of the primary output tube P1 is connected with a pull-up conversion resistor R2, the drain end of the auto-zero operational amplifier A6329 is connected with a variable resistor array R1, the variable range end of the variable resistor array R1 is connected with the negative input end of the auto-zero operational amplifier A1, the full range end of the auto-zero operational amplifier A2 is connected with the negative input end and the output end of the zero-setting operational amplifier A2, zero-setting current Izero flows in or out from the connection position of the primary output tube P1 and the resistor array R1, the pull-up conversion resistor R2 is connected with the primary output tube P1 as a secondary input signal, the second-zero operational amplifier A3 is connected with the output tube A3, the output end of the secondary zero-setting operational amplifier end A3 is respectively connected with the gate ends of the secondary output tube P2 and the secondary output tube P3, the output tube P2 is connected with, the junction of the second-stage output tube P3 and the pull-up conversion resistor Ros is a Y point, a junction X is connected with the negative input end of the second-stage zero-setting operational amplifier A3 and the source end of the grounding path tube N2, the drain end of the grounding path tube N2 is grounded, the grid end is connected with the drain end of the second-stage output tube P3, meanwhile, an overvoltage control current Iover is output from the drain end of the second-stage output tube P3 and is input and loaded at the grid end of the grounding path tube N1 and the grid end of the grounding path tube N2, the source end of the grounding path tube N1 is connected with the junction Y, the drain end is grounded, the drain end of the second-stage output tube P2 is an output port, and meanwhile, an undervoltage compensating current Iende.

Preferably, the output port is connected with the conversion resistor R4, and the other end of the conversion resistor R4 is grounded.

A method for realizing the self-zeroing current type high-precision programmable gain amplifier is characterized in that: the method comprises the following steps:

1) converting the input voltage difference into current through a programmable resistor R1 by the input stage of an automatic zero-setting operational amplifier A1;

2) when the sensor conditioning circuit is applied, after the programmable resistor R1 is converted into current, zero adjustment control can be carried out on the differential voltage when the sensor is subjected to zero input by introducing Izero current, and the zero drift of the sensor is corrected;

3) at the output stage of the two-stage zero-setting operational amplifier A3, converting the previous-stage input voltage into current through a conversion resistor R3;

5) when the output voltage does not meet the minimum requirement, current is injected through the Iuder current, and the input is raised;

6) when the output voltage is greater than the required voltage, Iover current is injected into a conversion resistor Ros, an earth passage tube N1 and an earth passage tube N2 are opened, and redundant current is discharged to the earth to ensure the satisfaction; and outputting voltage limitation.

Preferably, the Izero current in step 2) is realized by injecting current and extracting current.

Preferably, the sizes of the conversion resistor R3 and the conversion resistor Ros in the step 4), and the secondary output tube P2 and the secondary output tube P3 are proportionally designed to ensure that the voltages VX and VY are always equal.

The invention provides a self-zeroing current type high-precision programmable gain amplifier and a method, wherein the amplifier comprises an automatic zeroing operational amplifier, a programmable resistor array, a zeroing current, an under-voltage current and an overvoltage current-pumping. The Iuder current and the Iover current are added into an output stage and an output feedback loop to control the upper limit and the lower limit of output voltage, the 3 kinds of control current can adopt a simple current mirror mode, and the currents with different sizes are selected to be suitable for different sensor requirements, so that the input signals of the sensor can be accurately amplified, zeroed and the upper limit and the lower limit of the output can be controlled. Therefore, the invention has the following advantages:

1) the invention can amplify the input signal of the sensor accurately in proportion by matching the automatic zero-setting operational amplifier, the programmable resistor and various pumping and filling circuits, zero-setting the zero point of the sensor and controlling the amplitude of the output signal.

2) The invention adopts a current mode to control and output the pumping and filling of current, and has simple structure, convenient operation and strong anti-interference capability.

3) The invention adopts the current form to avoid the precision error caused by long-distance transmission, and can simply use the current pumping and current filling forms to limit the amplitude of the amplified output signal, so that the output signal is suitable for various devices at the later stage.

Drawings

Fig. 1 is a schematic circuit diagram of the present invention.

Detailed Description

The technical solution of the present invention is further described in detail with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1, the structure of the embodiment of the present invention includes an auto-zero operational amplifier a1, a zero-setting operational amplifier a2, and a secondary zero-setting operational amplifier A3, where an input signal VIN1 is connected to the positive input terminal of the auto-zero operational amplifier a1, the output terminal of the auto-zero operational amplifier a1 is connected to a primary output tube P1, the source terminal of the primary output tube P1 is pulled up by a transfer resistor R2, the drain terminal is connected to a variable resistor array R1, the variable magnitude terminal of the variable resistor array R1 is connected to the negative input terminal of the auto-zero operational amplifier a1, the full-range terminal is connected to the negative input terminal and the output terminal of the zero-setting operational amplifier a2, a VIN2 signal is connected to the positive input terminal of the zero-setting operational amplifier a2, a zero-setting current Izero flows in or out from the connection between the primary output tube P1 and the resistor array R1, a connection point of the pull-up transfer resistor R2 and the primary output tube P1 is connected to a secondary input signal, and a 599 of the secondary output tube P5928, the source end of a secondary output tube P2 is connected with a pull-up conversion resistor R3, the source end of a secondary output tube P3 is connected with a pull-up conversion resistor Ros, the joint of the secondary output tube P2 and the conversion resistor R3 is a junction X, the joint of the secondary output tube P3 and the pull-up conversion resistor Ros is a Y point, the junction X is connected with the negative input end of a secondary zeroing operational amplifier A3 and the source end of a grounding path tube N2, the drain end of the grounding path tube N2 is grounded, the gate end is connected with the drain end of a secondary output tube P3, an overvoltage control current Iover is output from the drain end of a secondary output tube P3 and is loaded at the gate end of the grounding path tube N1 and the gate end of the grounding path tube N2, the source end of the grounding path tube N1 is connected with the junction Y, the drain end is grounded, the drain end of the secondary output tube P2 is an output port, and an under-voltage compensation current Iender flows into the output port, the output port is connected.

The circuit of the invention adopts the automatic zero-setting operational amplifier A1 as a basic unit, and the circuit can greatly reduce the input offset voltage through the sampling capacitor and the switch;

the invention also provides a method for realizing the self-zeroing current type high-precision programmable gain amplifier, which comprises the following steps:

1) converting the input voltage difference into current through a programmable resistor R1 by the input stage of an automatic zero-setting operational amplifier A1;

2) when the sensor conditioning circuit is applied, after the programmable resistor R1 is converted into current, zero adjustment current Izero is introduced to perform zero adjustment control on the differential voltage when the sensor is subjected to zero input, and the zero drift of the sensor is corrected;

3) at the output stage of the second-stage zero-setting operational amplifier A3, converting the front-stage input voltage into current through a conversion resistor R3, and proportionally designing the sizes of the conversion resistor R3, the conversion resistor Ros and a second-stage output tube P2 and a second-stage output tube P3 to ensure that the voltages VX and VY are always equal;

5) when the output voltage does not meet the minimum requirement, the input is raised through injecting current by the undervoltage compensation current Iunder;

6) when the output voltage is greater than the required voltage, outputting overvoltage control current Iover to inject into a conversion resistor Ros, opening a grounding passage pipe N1 and a grounding passage pipe N2, and discharging redundant current to the ground to ensure the satisfaction; and outputting voltage limitation.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.