Auto-zero amplifier and ripple elimination method

Abstract

The present invention relates to an auto-zero amplifier and a ripple elimination method. The amplifier comprises a fully differential input stage and a second amplifier stage; and further comprises a dynamic common-mode feedback module adaptively connected to the second amplifier stage and the two auto-zero input stages within the fully differential input stage. When any auto-zero input stage within the fully differential input stage is in an amplifying operating state, the operating state common-mode feedback unit generates an amplifying operating common-mode feedback control signal, so that the auto-zero input stage in the amplifying operating state outputs a constant auto-zero amplifying common-mode voltage in response to a received differential input voltage and the amplifying operating common-mode feedback control signal. This constant auto-zero amplifying common-mode voltage ensures that the differential common-mode voltage received by the second amplifier stage remains constant. The present invention prevents the common-mode voltage output by the fully differential input stage from experiencing a jump process, thereby eliminating ripple in the output signal caused by common-mode voltage jumps.

Description

Technical Field

[0001] The present invention relates to an amplifier and a self-stabilizing method, in particular to an auto-zero amplifier and a self-stabilizing method. Background Art

[0002] The positive and negative inputs of an ideal operational amplifier exhibit a "virtual short" characteristic, meaning they are at the same potential. However, due to factors such as semiconductor device mismatch, the actual circuitry within an operational amplifier is not completely symmetrical, resulting in a millivolt-level voltage difference between the positive and negative inputs. This voltage is called offset voltage.

[0003] Auto-zero operational amplifiers dynamically correct the offset voltage to reduce it to the microvolt level and significantly reduce offset voltage drift due to factors such as temperature and time. Auto-zero operational amplifiers typically employ a two-stage or higher structure, in which a fully differential input stage is used to dynamically correct the input offset voltage. The fully differential input stage requires a common-mode feedback circuit to stabilize the output common-mode voltage. However, the two fully differential input stages of existing auto-zero amplifiers struggle to achieve complete matching of the output common-mode voltage. This results in the common-mode voltage output by the fully differential input stages also needing to switch alternately when the two fully differential input stages operate alternately, which in turn causes periodic ripple in the output signal of the entire auto-zero operational amplifier. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide an auto-zero amplifier and a ripple elimination method, which prevent the common-mode voltage output by the fully differential input stage from undergoing a jump process and eliminate the ripple of the output signal caused by the common-mode voltage jump.

[0005] According to the technical solution provided by the present invention, the auto-zero amplifier includes a fully differential input stage and a second amplifying stage adaptively connected to the fully differential input stage. The fully differential input stage includes two zero-stabilizing input stages connected in parallel. When one zero-stabilizing input stage in the fully differential input stage is configured to be in an amplifying working state, the other zero-stabilizing input stage of the fully differential input stage is configured to be in a zero-stabilizing calibration working state, and the fully differential output end of the zero-stabilizing input stage configured only in the amplifying working state is adaptively connected to the fully differential input end of the second amplifying stage.

[0006] It also includes a dynamic common-mode feedback module adaptively connected to the second amplification stage and the two zero-stabilizing input stages in the fully differential input stage, wherein the dynamic common-mode feedback module includes a working state common-mode feedback part and a zero-stabilizing calibration common-mode feedback part;

[0007] When any zero-stabilizing input stage in the fully differential input stage is in a zero-stabilizing calibration working state, the zero-stabilizing input stage in the zero-stabilizing calibration working state is adaptively connected to the zero-stabilizing input stage via a zero-stabilizing calibration common-mode feedback portion, and the zero-stabilizing calibration common-mode feedback portion is used to stabilize the zero-stabilizing calibration common-mode voltage output by the connected zero-stabilizing input stage;

[0008] When any stable zero input stage in the fully differential input stage is configured to be in an amplifying working state, the stable zero input stage in the amplifying working state is adaptively connected to the working state common-mode feedback unit. For the stable zero input stage in the amplifying working state, the working state common-mode feedback unit generates an amplifying working common-mode feedback control signal according to the common-mode voltage at the fully differential output end of the stable zero input stage in the amplifying working state, and loads the generated amplifying working common-mode feedback control signal to the common-mode feedback control end of the stable zero input stage in the amplifying working state, so that the stable zero input stage in the amplifying working state outputs a constant stable zero amplifying common-mode voltage under the received differential input voltage and the amplifying working common-mode feedback control signal, and the differential common-mode voltage received by the second amplifying stage is made constant by the constant stable zero amplifying common-mode voltage.

[0009] The working state common mode feedback unit includes a working state common mode feedback sub-circuit and a working common mode feedback switching switch group adapted to the working state common mode feedback sub-circuit;

[0010] When any zero-stabilizing input stage in the fully differential input stage is configured to be in the amplifying working state, the working state of the switch in the working common-mode feedback switching switch group is configured at the same time, so that the working state common-mode feedback sub-circuit is adaptively connected to the zero-stabilizing input stage in the amplifying working state.

[0011] The zero-stabilization calibration common-mode feedback unit includes a zero-stabilization calibration common-mode feedback sub-circuit and a first zero-stabilization calibration switching switch group adapted to the zero-stabilization calibration common-mode feedback sub-circuit;

[0012] When any zero-stabilizing input stage in the fully differential input stage is configured to be in the zero-stabilizing calibration working state, the working state of the switching switch in the zero-stabilizing calibration switching switch group is configured at the same time, so that the zero-stabilizing calibration common-mode feedback sub-circuit is adaptively connected to the zero-stabilizing input stage in the zero-stabilizing calibration working state, and the zero-stabilizing calibration common-mode feedback sub-circuit is used to stabilize the zero-stabilizing calibration common-mode voltage output by the connected zero-stabilizing input stage.

[0013] The zero-stabilization calibration common-mode feedback section includes two zero-stabilization calibration common-mode feedback sub-circuits and a second zero-stabilization calibration switching switch group adapted to the zero-stabilization calibration common-mode feedback sub-circuits, wherein the zero-stabilization calibration common-mode feedback sub-circuits are in one-to-one correspondence with the zero-stabilization input stages;

[0014] When any zero-stable input stage in the fully differential input stage is configured to be in the zero-stable calibration working state, the working state of the switch in the second zero-stable calibration switch group is also configured so that the zero-stable input stage is adaptively connected to the corresponding zero-stable calibration common-mode feedback sub-circuit.

[0015] For the two zero-stable input stages in the fully differential input stage, the differential output end of one zero-stable input stage is adaptively connected to the corresponding differential input end of the second amplifier stage via the switching switch S1 and the switching switch S2, respectively, and the differential output end of the other zero-stable input stage is adaptively connected to the corresponding differential input end of the second amplifier stage via the switching switch S3 and the switching switch S4, respectively.

[0016] When the switch S1 and the switch S2 are both closed, the switch S3 and the switch S4 are both open, the zero-stabilizing input stage connected to the switch S1 and the switch S2 is configured to be in the amplification working state, and the zero-stabilizing input stage connected to the switch S3 and the switch S4 is configured to be in the zero-stabilizing calibration working state;

[0017] When the switching switch S3 and the switching switch S4 are both in the closed state, the switching switch S1 and the switching switch S2 are in the open state, the stable zero input stage adapted to be connected to the switching switch S1 and the switching switch S2 is configured to be in the stable zero calibration working state, and the stable zero input stage adapted to be connected to the switching switch S3 and the switching switch S4 is configured to be in the amplification working state.

[0018] The working common-mode feedback switching switch group includes a switching switch S13 and a switching switch S14, wherein one end of the switching switch S13 and one end of the switching switch S14 are connected to the output end of the working state common-mode feedback sub-circuit, the other end of the switching switch S13 is connected to the common-mode feedback control end of a stable zero input stage, and the other end of the switching switch S14 is connected to the common-mode feedback control end of another stable zero input stage.

[0019] A method for eliminating ripple in an auto-zero amplifier is provided, wherein the auto-zero amplifier includes a fully differential input stage and a second amplifying stage adaptively connected to the fully differential input stage, the fully differential input stage including two zero-stabilizing input stages connected in parallel, when one zero-stabilizing input stage in the fully differential input stage is configured to be in an amplifying working state, the other zero-stabilizing input stage in the fully differential input stage is configured to be in a zero-stabilizing calibration working state, and the fully differential output end of the zero-stabilizing input stage configured only in the amplifying working state is adaptively connected to the fully differential input end of the second amplifying stage;

[0020] It also includes a dynamic common-mode feedback module adaptively connected to the second amplification stage and the two zero-stabilizing input stages in the fully differential input stage, wherein the dynamic common-mode feedback module includes a working state common-mode feedback part and a zero-stabilizing calibration common-mode feedback part;

[0021] When any zero-stabilizing input stage in the fully differential input stage is in a zero-stabilizing calibration working state, the zero-stabilizing input stage in the zero-stabilizing calibration working state is adaptively connected to the zero-stabilizing input stage via a zero-stabilizing calibration common-mode feedback portion, and the zero-stabilizing calibration common-mode feedback portion is used to stabilize the zero-stabilizing calibration common-mode voltage output by the connected zero-stabilizing input stage;

[0022] When any stable zero input stage in the fully differential input stage is configured to be in an amplifying working state, the stable zero input stage in the amplifying working state is adaptively connected to the working state common-mode feedback unit. For the stable zero input stage in the amplifying working state, the working state common-mode feedback unit generates an amplifying working common-mode feedback control signal according to the common-mode voltage at the fully differential output end of the stable zero input stage in the amplifying working state, and loads the generated amplifying working common-mode feedback control signal to the common-mode feedback control end of the stable zero input stage in the amplifying working state, so that the stable zero input stage in the amplifying working state outputs a constant stable zero amplifying common-mode voltage under the received differential input voltage and the amplifying working common-mode feedback control signal, and the differential common-mode voltage received by the second amplifying stage is made constant by the constant stable zero amplifying common-mode voltage.

[0023] The working state common mode feedback unit includes a working state common mode feedback sub-circuit and a working common mode feedback switching switch group adapted to the working state common mode feedback sub-circuit;

[0024] When any zero-stabilizing input stage in the fully differential input stage is configured to be in the amplifying working state, the working state of the switch in the working common-mode feedback switching switch group is configured at the same time, so that the working state common-mode feedback sub-circuit is adaptively connected to the zero-stabilizing input stage in the amplifying working state.

[0025] The zero-stabilization calibration common-mode feedback unit includes a zero-stabilization calibration common-mode feedback sub-circuit and a first zero-stabilization calibration switching switch group adapted to the zero-stabilization calibration common-mode feedback sub-circuit;

[0026] When any zero-stabilizing input stage in the fully differential input stage is configured to be in the zero-stabilizing calibration working state, the working state of the switching switch in the zero-stabilizing calibration switching switch group is configured at the same time, so that the zero-stabilizing calibration common-mode feedback sub-circuit is adaptively connected to the zero-stabilizing input stage in the zero-stabilizing calibration working state, and the zero-stabilizing calibration common-mode feedback sub-circuit is used to stabilize the zero-stabilizing calibration common-mode voltage output by the connected zero-stabilizing input stage.

[0027] The zero-stabilization calibration common-mode feedback section includes two zero-stabilization calibration common-mode feedback sub-circuits and a second zero-stabilization calibration switching switch group adapted to the zero-stabilization calibration common-mode feedback sub-circuits, wherein the zero-stabilization calibration common-mode feedback sub-circuits are in one-to-one correspondence with the zero-stabilization input stages;

[0028] When any zero-stable input stage in the fully differential input stage is configured to be in the zero-stable calibration working state, the working state of the switch in the second zero-stable calibration switch group is also configured at the same time, so that the zero-stable input stage is adaptively connected to the corresponding zero-stable calibration common-mode feedback sub-circuit.

[0029] The advantages of the present invention are as follows: when any zero-stable input stage in the fully differential input stage is configured to be in an amplifying working state, the zero-stable input stage in the amplifying working state is adaptively connected to the working state common-mode feedback unit, and the working state common-mode feedback unit generates an amplifying working common-mode feedback control signal, and loads the generated amplifying working common-mode feedback control signal to the common-mode feedback control end of the zero-stable input stage in the amplifying working state, so that the zero-stable input stage in the amplifying working state outputs a constant zero-stable amplifying common-mode voltage under the received differential input voltage and the amplifying working common-mode feedback control signal. The constant zero-stable amplifying common-mode voltage makes the differential common-mode voltage received by the second amplifying stage constant, thereby avoiding the common-mode voltage output by the fully differential input stage from undergoing a jump process, and eliminating the ripple of the output signal caused by the common-mode voltage jump. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a principle block diagram of the present invention.

[0031] Figure 2 1 is a timing diagram of the clock signal Φ1 and the clock signal Φ2 of the present invention.

[0032] Figure 3 Schematic diagram of the first embodiment of the present invention.

[0033] Figure 4 Schematic diagram of a second embodiment of the present invention.

[0034] Figure 5 Schematic diagram of a third embodiment of the present invention.

[0035] Explanation of the figure numbers: 1-dynamic common-mode feedback module, 2-first zero-stabilization calibration common-mode feedback sub-circuit, 3-second zero-stabilization calibration common-mode feedback sub-circuit, 4-first working state common-mode feedback sub-circuit, 5-third zero-stabilization calibration common-mode feedback sub-circuit, 6-second working state common-mode feedback sub-circuit, 7-fourth zero-stabilization calibration common-mode feedback sub-circuit and 8-third working state common-mode feedback sub-circuit. DETAILED DESCRIPTION

[0036] The present invention will be further described below with reference to specific drawings and embodiments.

[0037] In order to prevent the common-mode voltage output by the fully differential input stage from experiencing a jump process and eliminate the ripple of the output signal caused by the common-mode voltage jump, the present invention includes a fully differential input stage and a second amplifier stage adaptively connected to the fully differential input stage. The fully differential input stage includes two zero-stabilizing input stages connected in parallel. When one of the zero-stabilizing input stages in the fully differential input stage is configured to be in an amplifying working state, the other zero-stabilizing input stage of the fully differential input stage is configured to be in a zero-stabilizing calibration working state, and the fully differential output end of the zero-stabilizing input stage configured only in the amplifying working state is adaptively connected to the fully differential input end of the second amplifier stage.

[0038] It also includes a dynamic common-mode feedback module 1 adaptively connected to the second amplification stage and the two zero-stabilizing input stages in the fully differential input stage, wherein the dynamic common-mode feedback module 1 includes a working state common-mode feedback part and a zero-stabilizing calibration common-mode feedback part;

[0039] When any zero-stable input stage in the fully differential input stage is in the zero-stable calibration working state, the zero-stable input stage in the zero-stable calibration working state is fed back through the zero-stable calibration common mode feedback unit. and The zero-stabilizing input stage is adaptively connected, and the zero-stabilizing calibration common-mode feedback part is used to stabilize the zero-stabilizing calibration state common-mode voltage output by the connected zero-stabilizing input stage;

[0040] When any stable zero input stage in the fully differential input stage is configured to be in an amplifying working state, the stable zero input stage in the amplifying working state is adaptively connected to the working state common-mode feedback unit. For the stable zero input stage in the amplifying working state, the working state common-mode feedback unit generates an amplifying working common-mode feedback control signal according to the common-mode voltage at the fully differential output end of the stable zero input stage in the amplifying working state, and loads the generated amplifying working common-mode feedback control signal to the common-mode feedback control end of the stable zero input stage in the amplifying working state, so that the stable zero input stage in the amplifying working state outputs a constant stable zero amplifying common-mode voltage under the received differential input voltage and the amplifying working common-mode feedback control signal, and the differential common-mode voltage received by the second amplifying stage is made constant by the constant stable zero amplifying common-mode voltage.

[0041] Specifically, Figure 1 The schematic diagram of the auto-zero amplifier of the present invention is shown in FIG. The main structure of the auto-zero amplifier of the present invention is similar to the existing one, that is, it includes a fully differential input stage and a second amplification stage. Both the fully differential input stage and the second amplification stage can adopt the existing commonly used forms, and can be selected according to specific needs.

[0042] For two parallel-connected zero-stabilizing input stages within a fully differential input stage, when one of the zero-stabilizing input stages is configured to be in an amplifying state, the other zero-stabilizing input stage is configured to be in a zero-stabilizing calibration state, and only the fully differential output terminal of the zero-stabilizing input stage configured to be in the amplifying state is adaptively connected to the fully differential input terminal of the second amplifying stage. Specifically, Figure 1 In the embodiment, the two parallel-connected stable zero input stages are respectively the stable zero input stage A and the stable zero input stage B. The specific working process of the stable zero input stage A, the stable zero input stage B and the second amplifier stage in the fully differential input stage is consistent with the existing one. For example, if the stable zero input stage A is configured in the amplification working state, the stable zero input stage B is automatically configured in the stable zero calibration working state; similarly, when the stable zero input stage B is configured in the amplification working state, the stable zero input stage A is automatically configured in the stable zero calibration working state. Only the stable zero input stage A in the amplification working mode or the stable zero input stage B in the amplification working mode can be adaptively connected to the fully differential input end of the second amplifier stage. The stable zero input stage B in the stable zero calibration working state or the stable zero input stage A in the stable zero calibration working state is disconnected from the fully differential input end of the second amplifier stage.

[0043] In an embodiment of the present invention, a dynamic common-mode feedback module 1 is adaptively connected with the second amplifier stage, the zero-stabilizing input stage A, and the zero-stabilizing input stage B, wherein the dynamic common-mode feedback module 1 includes a working state common-mode feedback unit and a zero-stabilizing calibration common-mode feedback unit; the working state common-mode feedback unit and the zero-stabilizing calibration common-mode feedback unit in the dynamic common-mode feedback module 1 are dynamically connected and coordinated with the zero-stabilizing input stage A and the zero-stabilizing input stage B, so that the differential common-mode voltage received by the second amplifier stage is constant, thereby eliminating the ripple of the output signal caused by the common-mode voltage jump.

[0044] When any stable zero input stage in the fully differential input stage is configured to be in a stable zero calibration working state, the stable zero input stage in the stable zero calibration working state is adaptively connected to the stable zero input stage through the stable zero calibration common-mode feedback part, so that the stable zero input stage in the stable zero calibration working state works under the stable zero calibration common-mode feedback part, the stable zero calibration common-mode feedback part obtains the common-mode voltage of the fully differential output end of the connected stable zero input stage, and generates a stable zero calibration common-mode feedback control signal, and loads the generated stable zero calibration common-mode feedback control signal to the common-mode feedback control end of the connected stable zero input stage, that is, the stable zero calibration common-mode feedback part is used to stabilize the stable zero calibration common-mode voltage output by the connected stable zero input stage, thereby ensuring that the stable zero input stage in the stable zero calibration working state remains in the current working state.

[0045] The zero-stabilizing input stage in the zero-stabilizing calibration working state can output a zero-stabilizing calibration common-mode voltage under the zero-stabilizing calibration common-mode feedback control signal. The zero-stabilizing calibration common-mode voltage is generally matched with the constant zero-stabilizing amplification common-mode voltage output by the zero-stabilizing input stage currently in the amplification working state, that is, the zero-stabilizing calibration common-mode voltage is equal to the constant zero-stabilizing amplification common-mode voltage, or the difference between the two is within an allowable range, which is consistent with the existing and is well known to people in this technical field, and will not be repeated here.

[0046] In a specific implementation, when any zero-stabilizing input stage within the fully differential input stage is configured to be in an amplifying operating state, the zero-stabilizing input stage in the amplifying operating state can be adaptively connected to the working state common-mode feedback unit. For the zero-stabilizing input stage in the amplifying operating state, the working state common-mode feedback unit can generate an amplifying common-mode feedback control signal based on the common-mode voltage at the fully differential output terminal of the zero-stabilizing input stage in the amplifying operating state, and apply the generated amplifying common-mode feedback control signal to the common-mode feedback control terminal of the zero-stabilizing input stage in the amplifying operating state. In other words, the zero-stabilizing input stage in the amplifying operating state cooperates with the working state common-mode feedback unit to operate in a negative feedback closed-loop state, so that the zero-stabilizing input stage in the amplifying operating state outputs a constant zero-stabilizing amplified common-mode voltage in response to the received differential input voltage and the amplifying common-mode feedback control signal. When the zero-stabilizing amplified common-mode voltage is applied to the fully differential input terminal of the second amplifying stage, the differential common-mode voltage received by the second amplifying stage can be kept constant by the constant zero-stabilizing amplifying common-mode voltage.

[0047] In an embodiment of the present invention, the working state common-mode feedback unit can adopt the existing commonly used common-mode feedback circuit form. The working state common-mode feedback unit can generate an amplified working common-mode feedback control signal according to the common-mode voltage of the fully differential output terminal of the stable zero input stage in the amplified working state, and load it to the common-mode feedback control terminal of the stable zero input stage in the amplified working state. The specific situation of the amplified working common-mode feedback control signal output by the working state common-mode feedback unit is related to the common-mode voltage of the fully differential output terminal of the stable zero input stage obtained, and is specifically consistent with the existing ones, well known to those in this technical field, and will not be repeated here. When the differential input voltage is stable, the output common-mode voltage of the stable zero input stage in the amplified working state can be adjusted or controlled by the amplified working common-mode feedback control signal, so that the stable zero amplified common-mode voltage output by the stable zero input stage remains constant. For the differential input voltage, that is Figure 1 The voltage difference between the INP terminal and the INN terminal is consistent with the existing one.

[0048] In summary, for the two zero-stabilizing input stages within the fully differential input stage, when either zero-stabilizing input stage is in the amplifying operating mode, the same working state common-mode feedback section is used to obtain a corresponding amplifying operating common-mode feedback control signal. Compared to the prior art in which the two zero-stabilizing input stages utilize two different common-mode feedback circuits to cooperate in common-mode feedback closed-loop control when in the amplifying operating mode, since the same working state common-mode feedback section is used, a corresponding amplifying operating common-mode feedback control signal can be obtained based on the common-mode voltage at the fully differential output end of the zero-stabilizing input stage in the amplifying operating mode. This ensures that either zero-stabilizing input stage can output the same zero-stabilizing amplified common-mode voltage when in the amplifying operating mode. The zero-stabilizing amplified common-mode voltage is the differential common-mode voltage applied to the second amplifying stage, thereby ensuring that the differential common-mode voltage received by the second amplifying stage is constant. This avoids incomplete matching of the different common-mode feedback circuits when each zero-stabilizing input stage utilizes different common-mode feedback circuits to implement common-mode feedback closed-loop control. This further prevents the common-mode voltage output by the fully differential input stage from experiencing a jump process, thereby eliminating ripple in the output signal caused by the common-mode voltage jump.

[0049] like Figure 1 、 Figure 3 、 Figure 4 and Figure 5 As shown, for the two zero-stable input stages in the fully differential input stage, the differential output end of one zero-stable input stage is adaptively connected to the corresponding differential input end of the second amplifier stage via the switching switch S1 and the switching switch S2, respectively, and the differential output end of the other zero-stable input stage is adaptively connected to the corresponding differential input end of the second amplifier stage via the switching switch S3 and the switching switch S4, respectively.

[0050] When the switch S1 and the switch S2 are both closed, the switch S3 and the switch S4 are both open, the zero-stabilizing input stage connected to the switch S1 and the switch S2 is configured to be in the amplification working state, and the zero-stabilizing input stage connected to the switch S3 and the switch S4 is configured to be in the zero-stabilizing calibration working state;

[0051] When the switching switch S3 and the switching switch S4 are both in the closed state, the switching switch S1 and the switching switch S2 are in the open state, the stable zero input stage adapted to be connected to the switching switch S1 and the switching switch S2 is configured to be in the stable zero calibration working state, and the stable zero input stage adapted to be connected to the switching switch S3 and the switching switch S4 is configured to be in the amplification working state.

[0052] In a specific implementation, the stable zero input stage adapted to be connected to the switching switch S1 and the switching switch S2 is the stable zero input stage A, and the stable zero input stage adapted to be connected to the switching switch S3 and the switching switch S4 is the stable zero input stage B. The switching switch S1, the switching switch S2, the switching switch S3 and the switching switch S4 can use the existing commonly used controllable switch form, and the specific type can be selected and determined according to actual needs, which is well known to personnel in this technical field.

[0053] In a specific implementation, the switches S1, S2, S3 and S4 are controlled by a timing sequence, wherein the switches S1 and S2 are controlled by a clock signal Φ1. Switch S3 and switch S4 are controlled by clock signal Φ2. Clock signal Φ1 and clock signal Φ2 are non-overlapping clock signals. Figure 2 As shown, the clock signal Φ1 and the clock signal Φ2 are both high level valid. When the clock signal Φ1 is in the valid state, the clock signal Φ2 is in the invalid state, or when the clock signal Φ2 is in the valid state, the clock signal Φ1 is in the valid state. Figure 2 It can be seen that the clock signal Φ1 and the clock signal Φ2 can be in the invalid state at the same time.

[0054] Specifically, when clock signal Φ1 is valid, switches S1 and S2 are both in the on-closed state, while switches S3 and S4 are in the off-state. At this point, stable zero input stage A is in the amplification state, while stable zero input stage B is in the zero calibration state. When clock signal Φ2 is valid, switches S1 and S2 are both in the off-state, while switches S3 and S4 are in the on-closed state. At this point, stable zero input stage A is configured in the zero calibration state, while stable zero input stage B is configured in the amplification state. Therefore, by using clock signals Φ1 and Φ2, stable zero input stage A and stable zero input stage B can be effectively configured to enter their respective operating states. The specific methods and processes for configuring stable zero input stage A and stable zero input stage B to enter their respective operating states are consistent with existing knowledge and are well known to those skilled in the art, and will not be further elaborated herein.

[0055] Furthermore, the working state common mode feedback unit includes a working state common mode feedback subcircuit and a working common mode feedback switching switch group adapted to the working state common mode feedback subcircuit;

[0056] When any zero-stabilizing input stage in the fully differential input stage is configured to be in the amplifying working state, the working state of the switch in the working common-mode feedback switching switch group is configured at the same time, so that the working state common-mode feedback sub-circuit is adaptively connected to the zero-stabilizing input stage in the amplifying working state.

[0057] Specifically, the working state common-mode feedback section includes a working state common-mode feedback subcircuit and a working common-mode feedback switching switch group. The working state common-mode feedback subcircuit outputs an amplified working common-mode feedback control signal, and the working state common-mode feedback switching switch group enables adaptive connection between the working state common-mode feedback subcircuit and the aforementioned zero-stabilizing input stage A or zero-stabilizing input stage B. The specific details of the working state common-mode feedback subcircuit and the working common-mode feedback switching switch group are described in detail in the following specific embodiments.

[0058] Furthermore, the zero-stabilization calibration common-mode feedback unit includes a zero-stabilization calibration common-mode feedback sub-circuit and a zero-stabilization calibration first switching switch group adapted to the zero-stabilization calibration common-mode feedback sub-circuit;

[0059] When any zero-stabilizing input stage in the fully differential input stage is configured to be in the zero-stabilizing calibration working state, the working state of the switching switch in the zero-stabilizing calibration switching switch group is configured at the same time, so that the zero-stabilizing calibration common-mode feedback sub-circuit is adaptively connected to the zero-stabilizing input stage in the zero-stabilizing calibration working state, and the zero-stabilizing calibration common-mode feedback sub-circuit is used to stabilize the zero-stabilizing calibration common-mode voltage output by the connected zero-stabilizing input stage.

[0060] The specific process of using the zero-stabilization calibration common-mode feedback subcircuit to stabilize the zero-stabilization calibration common-mode voltage output by the connected zero-stabilization input stage can be referred to the above description and will not be repeated here. When there is a zero-stabilization calibration common-mode feedback subcircuit and a zero-stabilization calibration first switching switch group adapted to the zero-stabilization calibration common-mode feedback subcircuit in the zero-stabilization calibration common-mode feedback part, the following is achieved by Figure 4 and Figure 5 , an example is given to illustrate the specific situation of the common-mode feedback part of the zero-stabilization calibration.

[0061] like Figure 4 As shown, a zero-stabilizing calibration common-mode feedback sub-circuit in the zero-stabilizing calibration common-mode feedback section is the third zero-stabilizing calibration common-mode feedback sub-circuit 5; at the same time, Figure 4 In the working state common mode feedback sub-circuit in the working state common mode feedback part is the second working state common mode feedback sub-circuit 6. Figure 4 In the embodiment, the first switching switch group for zero stabilization calibration includes switching switch S9, switching switch S10, switching switch S11, switching switch S12, switching switch S15 and switching switch S16, and the working common mode feedback switching switch group includes switching switch S13 and switching switch S14.

[0062] The common-mode feedback control terminal of the zero-stabilizing input stage A is connected to one end of the switching switch S13 and one end of the switching switch S15. The other end of the switching switch S13 is connected to the output end of the second working state common-mode feedback sub-circuit 6. The other end of the switching switch S15 is connected to the output end of the third zero-stabilizing calibration common-mode feedback sub-circuit 5 and one end of the switching switch S16. The other end of the switching switch S16 is connected to the common-mode feedback control terminal of the zero-stabilizing input stage B and one end of the switching switch S14. The other end of the switching switch S14 is connected to the output end of the second working state common-mode feedback sub-circuit 6.

[0063] One input terminal of the third zero-stabilizing calibration common-mode feedback sub-circuit 5 is connected to one terminal of switch S9 and one terminal of switch S11. Another input terminal of the third zero-stabilizing calibration common-mode feedback sub-circuit 5 is connected to one terminal of switch S10 and one terminal of switch S12. The other terminal of switch S9 is connected to one terminal of switch S2 and a differential output terminal of zero-stabilizing input stage A. The other terminal of switch S11 is connected to one terminal of switch S3 and a differential output terminal of zero-stabilizing input stage B. The other terminal of switch S10 is connected to one terminal of switch S1 and the other differential output terminal of zero-stabilizing input stage A. The other terminal of switch S12 is connected to one terminal of switch S4 and the other differential output terminal of zero-stabilizing input stage B. The other terminals of switches S1 and S4 are connected to a differential input terminal of the second amplifier stage and an input terminal of the second working common-mode feedback sub-circuit 6. The other terminals of switches S2 and S3 are connected to the other differential input terminal of the second amplifier stage and the other input terminal of the second working common-mode feedback sub-circuit 6.

[0064] Figure 4 In the figure, switches S1, S2, S11, S12, S13 and S16 are all controlled by clock signal Φ1, and switches S3, S4, S9, S10, S14 and S15 are all controlled by clock signal Φ2.

[0065] When clock signal Φ1 is valid, switch S13 is closed and switch S14 is opened. Zero-stabilizing input stage A is in the amplification operating state and is connected to the second operating state common-mode feedback sub-circuit 6 via switch S13. Switches S15, S9, and S10 are opened, disconnecting the third zero-stabilizing calibration common-mode feedback sub-circuit 5 from zero-stabilizing input stage A. When switches S16, S11, and S12 are closed, zero-stabilizing input stage B, in the zero-stabilizing calibration operating state, is adaptively connected to the third zero-stabilizing calibration common-mode feedback sub-circuit 5. The corresponding operating conditions when zero-stabilizing input stage B is adaptively connected to the third zero-stabilizing calibration common-mode feedback sub-circuit 5 can be referred to the above description and will not be repeated here.

[0066] When the clock signal Φ2 is valid, the switching switch S14 is turned on and closed, the switching switch S13 is turned off, and the zero-stabilizing input stage B in the amplification working state is connected to the second working state common-mode feedback sub-circuit 6; the switching switches S16, S11, and S12 are turned off, and the switching switches S15, S9, and S10 are turned on and closed, and the zero-stabilizing input stage A in the zero-stabilizing calibration working state is adaptively connected to the third zero-stabilizing calibration common-mode feedback sub-circuit 5.

[0067] In summary, when the stable zero input stage A or the stable zero input stage B is in the amplification working state, the second working state common-mode feedback sub-circuit 6 cooperates and generates an amplification working common-mode feedback control signal. When the stable zero input stage A or the stable zero input stage B cooperates with the second working state common-mode feedback sub-circuit 6 to work in a closed-loop working state, it can generate a constant stable zero amplification common-mode voltage. The constant stable zero amplification common-mode voltage makes the differential common-mode voltage received by the second amplification stage constant.

[0068] like Figure 5 FIG. 1 is a schematic diagram of another embodiment of the present invention, wherein a zero-stabilizing calibration common-mode feedback sub-circuit in the zero-stabilizing calibration common-mode feedback section is the fourth zero-stabilizing calibration common-mode feedback sub-circuit 7; and Figure 5 In the working state common mode feedback sub-circuit in the working state common mode feedback part is the third working state common mode feedback sub-circuit 8. Figure 5 In the figure, the first switching switch group for zero-stabilization calibration includes switching switch S17, switching switch S18, switching switch S19, switching switch S20, switching switch S21 and switching switch S22, and the working common-mode feedback switching switch group includes switching switch S23, switching switch S24, switching switch S25, switching switch S26, switching switch S27 and switching switch S28.

[0069] The common-mode feedback control terminal of the zero-stabilizing input stage A is connected to one end of the switching switch S23 and one end of the switching switch S17. The other end of the switching switch S23 is connected to the output end of the third working state common-mode feedback sub-circuit 8. The other end of the switching switch S17 is connected to the output end of the fourth zero-stabilizing calibration common-mode feedback sub-circuit 7 and one end of the switching switch S18. The other end of the switching switch S18 is connected to the common-mode feedback control terminal of the zero-stabilizing input stage B and one end of the switching switch S24. The other end of the switching switch S24 is connected to the output end of the third working state common-mode feedback sub-circuit 8.

[0070] One input end of the fourth zero-stabilizing calibration common-mode feedback sub-circuit 7 is connected to one end of the switching switch S19 and one end of the switching switch S20, one input end of the fourth zero-stabilizing calibration common-mode feedback sub-circuit 7 is connected to one end of the switching switch S21 and one end of the switching switch S22, the other end of the switching switch S19 is connected to one end of the switching switch S2, one end of the switching switch S25 and a differential output end of the zero-stabilizing input stage A, the other end of the switching switch S20 is connected to one end of the switching switch S3, one end of the switching switch S26 and a differential output end of the zero-stabilizing input stage B; the other end of the switching switch S21 is connected to one end of the switching switch S1, one end of the switching switch S27 and the other differential output end of the zero-stabilizing input stage A, and the other end of the switching switch S22 is connected to one end of the switching switch S4, one end of the switching switch S28 and the other differential output end of the zero-stabilizing input stage B.

[0071] The other end of the switching switch S25 and the other end of the switching switch S26 are connected to one input end of the third working state common-mode feedback sub-circuit 8, and the other end of the switching switch S27 and the other end of the switching switch S28 are connected to the other input end of the third working state common-mode feedback sub-circuit 8.

[0072] Switch S1, switch S2, switch S18, switch S20, switch S22, switch S23, switch S25, and switch S27 are controlled by clock signal Φ1, and switch S3, switch S4, switch S17, switch S19, switch S21, switch S24, switch S26, and switch S28 are controlled by clock signal Φ2.

[0073] Figure 5 The implementation status and Figure 4 The above descriptions are basically the same as those in the figure, that is, the on or off state of the corresponding switching switches is controlled by the clock signal Φ1 and the clock signal Φ2 to adapt to the corresponding working states of the stable zero input stage A and the stable zero input stage B. The case where the stable zero input stage A is in the amplification working state or the stable zero calibration working state can refer to the above descriptions. Similarly, the case where the stable zero input stage B is in the amplification working state or the stable zero calibration working state can refer to the above descriptions, which will not be repeated here.

[0074] Furthermore, the zero-stabilization calibration common-mode feedback section includes two zero-stabilization calibration common-mode feedback sub-circuits and a zero-stabilization calibration second switching switch group adapted to the zero-stabilization calibration common-mode feedback sub-circuits, wherein the zero-stabilization calibration common-mode feedback sub-circuits are in one-to-one correspondence with the zero-stabilization input stages;

[0075] When any zero-stable input stage in the fully differential input stage is configured to be in the zero-stable calibration working state, the working state of the switch in the second zero-stable calibration switch group is also configured at the same time, so that the zero-stable input stage is adaptively connected to the corresponding zero-stable calibration common-mode feedback sub-circuit.

[0076] like Figure 3 As shown, it shows the situation that the zero-stabilization calibration common-mode feedback part includes two zero-stabilization calibration common-mode feedback sub-circuits, and the two zero-stabilization calibration common-mode feedback sub-circuits are specifically the first zero-stabilization calibration common-mode feedback sub-circuit 2 and the second zero-stabilization calibration common-mode feedback sub-circuit 3, and the working state common-mode feedback sub-circuit in the working state common-mode feedback part is the first working state common-mode feedback sub-circuit 4. Figure 3 In the embodiment, the second switching switch group for zero stabilization calibration includes switching switch S5 and switching switch S6, and the working common mode feedback switching switch group includes switching switch S7 and switching switch S8.

[0077] Figure 3 In the figure, the common-mode feedback control terminal of the zero-stabilizing input stage A is connected to one end of the switching switch S5 and one end of the switching switch S7, the other end of the switching switch S5 is connected to the output end of the first zero-stabilizing calibration common-mode feedback sub-circuit 2, the other end of the switching switch S7 is connected to one end of the switching switch S8 and the output end of the first working state common-mode feedback sub-circuit 4, the other end of the switching switch S8 is connected to the common-mode feedback control terminal of the zero-stabilizing input stage B and one end of the switching switch S6, and the other end of the switching switch S6 is connected to the output end of the second zero-stabilizing calibration common-mode feedback sub-circuit 3.

[0078] One input terminal of the first zero-stabilizing calibration common-mode feedback sub-circuit 2 is connected to a differential output terminal of the zero-stabilizing input stage A and one end of the switch S1. The other input terminal of the first zero-stabilizing calibration common-mode feedback sub-circuit 2 is connected to the other differential output terminal of the zero-stabilizing input stage A and one end of the switch S2. One input terminal of the second zero-stabilizing calibration common-mode feedback sub-circuit 3 is connected to a differential output terminal of the zero-stabilizing input stage B and one end of the switch S3. The other input terminal of the second zero-stabilizing calibration common-mode feedback sub-circuit 3 is connected to the other differential output terminal of the zero-stabilizing input stage B and one end of the switch S4. The other ends of the switches S1 and S4 are connected to a differential input terminal of the second amplifier stage and an input terminal of the first working state common-mode feedback sub-circuit 4. The other ends of the switches S2 and S3 are connected to the other differential input terminal of the second amplifier stage and the other input terminal of the first working state common-mode feedback sub-circuit 4.

[0079] Figure 3 In the embodiment, the switches S1, S2, S6 and S7 are controlled by the clock signal Φ1, and the switches S3, S4, S5 and S8 are controlled by the clock signal Φ2.

[0080] When clock signal Φ1 is valid and clock signal Φ2 is invalid, switch S7 is closed and switch S5 is opened. Zero-stabilizing input stage A is in an amplifying state. The common-mode feedback control terminal of zero-stabilizing input stage A is connected to the output terminal of the first working state common-mode feedback sub-circuit 4, and the first zero-stabilizing calibration common-mode feedback sub-circuit 2 is disconnected from zero-stabilizing input stage A. Switch S8 is opened and switch S6 is closed. Zero-stabilizing input stage B is in a zero-stabilizing calibration state. The common-mode feedback control terminal of zero-stabilizing input stage B is connected to the output terminal of the second zero-stabilizing calibration common-mode feedback sub-circuit 3, that is, the second zero-stabilizing calibration common-mode feedback sub-circuit 3 cooperates with zero-stabilizing input stage B.

[0081] When clock signal Φ2 is valid and clock signal Φ1 is invalid, switch S8 is closed and switch S6 is opened. Zero-stabilizing input stage B is in an amplifying state, and the common-mode feedback control terminal of zero-stabilizing input stage B is connected to the output terminal of the first working state common-mode feedback sub-circuit 4. The second zero-stabilizing calibration common-mode feedback sub-circuit 2 is disconnected from zero-stabilizing input stage B. Switch S7 is opened and switch S5 is closed. Zero-stabilizing input stage A is in a zero-stabilizing calibration state, and the common-mode feedback control terminal of zero-stabilizing input stage A is connected to the output terminal of the first zero-stabilizing calibration common-mode feedback sub-circuit 2.

[0082] In summary, when the stable zero input stage A or the stable zero input stage B is in the amplification working state, the first working state common-mode feedback sub-circuit 4 cooperates and generates an amplification working common-mode feedback control signal. When the stable zero input stage A or the stable zero input stage B cooperates with the first working state common-mode feedback sub-circuit 4 to work in a closed-loop working state, it can generate a constant stable zero amplification common-mode voltage. The constant stable zero amplification common-mode voltage makes the differential common-mode voltage received by the second amplification stage constant.

[0083] When the zero-stabilizing input stage A is in the zero-stabilizing calibration operation, it is connected to the first zero-stabilizing calibration common-mode feedback sub-circuit 2; and when the zero-stabilizing input stage B is in the zero-stabilizing calibration operation, it is connected to the second zero-stabilizing calibration common-mode feedback sub-circuit 3; and the functions after the first zero-stabilizing calibration common-mode feedback sub-circuit 2 and the zero-stabilizing input stage A, and the second zero-stabilizing calibration common-mode feedback sub-circuit 3 and the zero-stabilizing input stage B are adaptively connected are consistent with the above description and will not be repeated here.

[0084] During specific implementation, the specific configuration of the zero-calibration common-mode feedback section can be selected based on actual needs. Once the number of zero-calibration common-mode feedback sub-circuits within the zero-calibration common-mode feedback section is determined, the specific configurations of the first zero-calibration switching switch group and the second zero-calibration switching switch group can be obtained. These configurations can be selected based on specific needs and are not further described here. Furthermore, the specific configurations of the working common-mode feedback sub-circuits and the working common-mode feedback switching switch group within the working common-mode feedback section can also be selected based on actual needs, so long as they meet the aforementioned operational specifications.

[0085] Specifically, the first zero-stabilization calibration common-mode feedback subcircuit 2, the second zero-stabilization calibration common-mode feedback subcircuit 2, the third zero-stabilization calibration common-mode feedback subcircuit 5, and the fourth zero-stabilization calibration common-mode feedback subcircuit 7 can employ conventional circuits, and the specific circuit form can be selected as needed. The first working state common-mode feedback subcircuit 4, the second working state common-mode feedback subcircuit 6, and the third working state common-mode feedback subcircuit 8 can also employ conventional circuits or other similar circuit forms, and the specific circuit form can be selected as needed. The specific method and process for generating the required amplified working common-mode feedback control signal using the first working state common-mode feedback subcircuit 4, the second working state common-mode feedback subcircuit 6, and the third working state common-mode feedback subcircuit 8 can also be consistent with existing methods and are well known to those skilled in the art, and will not be further described here.

[0086] In summary, the present invention provides a ripple elimination method for an auto-zero amplifier, providing an auto-zero amplifier, wherein the auto-zero amplifier includes a fully differential input stage and a second amplification stage adaptively connected to the fully differential input stage, the fully differential input stage includes two zero-stabilizing input stages connected in parallel, when one zero-stabilizing input stage within the fully differential input stage is configured to be in an amplification working state, the other zero-stabilizing input stage within the fully differential input stage is configured to be in a zero-stabilizing calibration working state, and the fully differential output end of the zero-stabilizing input stage configured only in the amplification working state is adaptively connected to the fully differential input end of the second amplification stage;

[0087] It also includes a dynamic common-mode feedback module 1 adaptively connected to the second amplification stage and the two zero-stabilizing input stages in the fully differential input stage, wherein the dynamic common-mode feedback module 1 includes a working state common-mode feedback part and a zero-stabilizing calibration common-mode feedback part;

[0088] When any zero-stabilizing input stage in the fully differential input stage is in a zero-stabilizing calibration working state, the zero-stabilizing input stage in the zero-stabilizing calibration working state is adaptively connected to the zero-stabilizing input stage via a zero-stabilizing calibration common-mode feedback portion, and the zero-stabilizing calibration common-mode feedback portion is used to stabilize the zero-stabilizing calibration common-mode voltage output by the connected zero-stabilizing input stage;

[0089] When any stable zero input stage in the fully differential input stage is configured to be in an amplifying working state, the stable zero input stage in the amplifying working state is adaptively connected to the working state common-mode feedback unit. For the stable zero input stage in the amplifying working state, the working state common-mode feedback unit generates an amplifying working common-mode feedback control signal according to the common-mode voltage at the fully differential output end of the stable zero input stage in the amplifying working state, and loads the generated amplifying working common-mode feedback control signal to the common-mode feedback control end of the stable zero input stage in the amplifying working state, so that the stable zero input stage in the amplifying working state outputs a constant stable zero amplifying common-mode voltage under the received differential input voltage and the amplifying working common-mode feedback control signal, and the differential common-mode voltage received by the second amplifying stage is made constant by the constant stable zero amplifying common-mode voltage.

[0090] Specifically, the specific coordinated working process of the fully differential input stage, the second amplification stage and the dynamic common-mode feedback module 1, as well as the coordinated process of the working state common-mode feedback part, the zero-stabilization calibration common-mode feedback part and the fully differential input stage can all be referred to the above description and will not be repeated here.

Claims

1. An auto-zero amplifier, comprising a fully differential input stage and a second amplifier stage adaptively connected to the fully differential input stage, wherein the fully differential input stage includes two zero-stabilizing input stages connected in parallel, wherein when one of the zero-stabilizing input stages is configured to be in an amplifying state, the other zero-stabilizing input stage of the fully differential input stage is configured to be in a zero-stabilizing calibration state, and the fully differential output terminal of the zero-stabilizing input stage configured only to be in the amplifying state is adaptively connected to the fully differential input terminal of the second amplifier stage; wherein: It also includes a dynamic common-mode feedback module (1) adaptively connected to the second amplification stage and the two zero-stabilizing input stages in the fully differential input stage, wherein the dynamic common-mode feedback module (1) includes a working state common-mode feedback part and a zero-stabilizing calibration common-mode feedback part; When any zero-stabilizing input stage in the fully differential input stage is in a zero-stabilizing calibration working state, the zero-stabilizing input stage in the zero-stabilizing calibration working state is adaptively connected to the zero-stabilizing input stage via a zero-stabilizing calibration common-mode feedback portion, and the zero-stabilizing calibration common-mode feedback portion is used to stabilize the zero-stabilizing calibration common-mode voltage output by the connected zero-stabilizing input stage; When any stable zero input stage in the fully differential input stage is configured to be in an amplifying working state, the stable zero input stage in the amplifying working state is adaptively connected to the working state common-mode feedback unit. For the stable zero input stage in the amplifying working state, the working state common-mode feedback unit generates an amplifying working common-mode feedback control signal according to the common-mode voltage at the fully differential output end of the stable zero input stage in the amplifying working state, and loads the generated amplifying working common-mode feedback control signal to the common-mode feedback control end of the stable zero input stage in the amplifying working state, so that the stable zero input stage in the amplifying working state outputs a constant stable zero amplifying common-mode voltage under the received differential input voltage and the amplifying working common-mode feedback control signal, and the differential common-mode voltage received by the second amplifying stage is made constant by the constant stable zero amplifying common-mode voltage.

2. The auto-zero amplifier according to claim 1, wherein: The working state common mode feedback unit includes a working state common mode feedback sub-circuit and a working common mode feedback switching switch group adapted to the working state common mode feedback sub-circuit; When any zero-stabilizing input stage in the fully differential input stage is configured to be in the amplifying working state, the working state of the switch in the working common-mode feedback switching switch group is configured at the same time, so that the working state common-mode feedback sub-circuit is adaptively connected to the zero-stabilizing input stage in the amplifying working state.

3. The auto-zero amplifier according to claim 2, wherein: The zero-stabilization calibration common-mode feedback unit includes a zero-stabilization calibration common-mode feedback sub-circuit and a first zero-stabilization calibration switching switch group adapted to the zero-stabilization calibration common-mode feedback sub-circuit; When any zero-stabilizing input stage in the fully differential input stage is configured to be in the zero-stabilizing calibration working state, the working state of the switching switch in the zero-stabilizing calibration switching switch group is configured at the same time, so that the zero-stabilizing calibration common-mode feedback sub-circuit is adaptively connected to the zero-stabilizing input stage in the zero-stabilizing calibration working state, and the zero-stabilizing calibration common-mode feedback sub-circuit is used to stabilize the zero-stabilizing calibration common-mode voltage output by the connected zero-stabilizing input stage.

4. The auto-zero amplifier according to claim 2, wherein: The zero-stabilization calibration common-mode feedback section includes two zero-stabilization calibration common-mode feedback sub-circuits and a second zero-stabilization calibration switching switch group adapted to the zero-stabilization calibration common-mode feedback sub-circuits, wherein the zero-stabilization calibration common-mode feedback sub-circuits are in one-to-one correspondence with the zero-stabilization input stages; When any zero-stable input stage in the fully differential input stage is configured to be in the zero-stable calibration working state, the working state of the switch in the second zero-stable calibration switch group is also configured at the same time, so that the zero-stable input stage is adaptively connected to the corresponding zero-stable calibration common-mode feedback sub-circuit.

5. The auto-zero amplifier according to any one of claims 1 to 4, characterized in that: For the two zero-stable input stages in the fully differential input stage, the differential output end of one zero-stable input stage is adaptively connected to the corresponding differential input end of the second amplifier stage via the switching switch S1 and the switching switch S2, respectively, and the differential output end of the other zero-stable input stage is adaptively connected to the corresponding differential input end of the second amplifier stage via the switching switch S3 and the switching switch S4, respectively. When the switch S1 and the switch S2 are both closed, the switch S3 and the switch S4 are both open, the zero-stabilizing input stage connected to the switch S1 and the switch S2 is configured to be in the amplification working state, and the zero-stabilizing input stage connected to the switch S3 and the switch S4 is configured to be in the zero-stabilizing calibration working state; When the switching switch S3 and the switching switch S4 are both in the closed state, the switching switch S1 and the switching switch S2 are in the open state, the stable zero input stage adapted to be connected to the switching switch S1 and the switching switch S2 is configured to be in the stable zero calibration working state, and the stable zero input stage adapted to be connected to the switching switch S3 and the switching switch S4 is configured to be in the amplification working state.

6. The auto-zero amplifier according to claim 2, wherein: The working common-mode feedback switching switch group includes a switching switch S13 and a switching switch S14, wherein one end of the switching switch S13 and one end of the switching switch S14 are connected to the output end of the working state common-mode feedback sub-circuit, the other end of the switching switch S13 is connected to the common-mode feedback control end of a stable zero input stage, and the other end of the switching switch S14 is connected to the common-mode feedback control end of another stable zero input stage.

7. A method for eliminating ripple of an auto-zero amplifier, providing an auto-zero amplifier, wherein: The auto-zero amplifier includes a fully differential input stage and a second amplifying stage adaptively connected to the fully differential input stage. The fully differential input stage includes two zero-stabilizing input stages connected in parallel. When one zero-stabilizing input stage in the fully differential input stage is configured to be in an amplifying working state, the other zero-stabilizing input stage in the fully differential input stage is configured to be in a zero-stabilizing calibration working state. The fully differential output end of the zero-stabilizing input stage configured only to be in the amplifying working state is adaptively connected to the fully differential input end of the second amplifying stage. The auto-zero amplifier is characterized in that: It also includes a dynamic common-mode feedback module (1) adaptively connected to the second amplification stage and the two zero-stabilizing input stages in the fully differential input stage, wherein the dynamic common-mode feedback module (1) includes a working state common-mode feedback part and a zero-stabilizing calibration common-mode feedback part; When any zero-stabilizing input stage in the fully differential input stage is in a zero-stabilizing calibration working state, the zero-stabilizing input stage in the zero-stabilizing calibration working state is adaptively connected to the zero-stabilizing input stage via a zero-stabilizing calibration common-mode feedback portion, and the zero-stabilizing calibration common-mode feedback portion is used to stabilize the zero-stabilizing calibration common-mode voltage output by the connected zero-stabilizing input stage; When any stable zero input stage in the fully differential input stage is configured to be in an amplifying working state, the stable zero input stage in the amplifying working state is adaptively connected to the working state common-mode feedback unit. For the stable zero input stage in the amplifying working state, the working state common-mode feedback unit generates an amplifying working common-mode feedback control signal according to the common-mode voltage at the fully differential output end of the stable zero input stage in the amplifying working state, and loads the generated amplifying working common-mode feedback control signal to the common-mode feedback control end of the stable zero input stage in the amplifying working state, so that the stable zero input stage in the amplifying working state outputs a constant stable zero amplifying common-mode voltage under the received differential input voltage and the amplifying working common-mode feedback control signal, and the differential common-mode voltage received by the second amplifying stage is made constant by the constant stable zero amplifying common-mode voltage.

8. The ripple elimination method of the auto-zero amplifier according to claim 7, characterized in that: The working state common mode feedback unit includes a working state common mode feedback sub-circuit and a working common mode feedback switching switch group adapted to the working state common mode feedback sub-circuit; When any zero-stabilizing input stage in the fully differential input stage is configured to be in the amplifying working state, the working state of the switch in the working common-mode feedback switching switch group is configured at the same time, so that the working state common-mode feedback sub-circuit is adaptively connected to the zero-stabilizing input stage in the amplifying working state.

9. The ripple elimination method of the auto-zero amplifier according to claim 8, characterized in that: The zero-stabilization calibration common-mode feedback unit includes a zero-stabilization calibration common-mode feedback sub-circuit and a first zero-stabilization calibration switching switch group adapted to the zero-stabilization calibration common-mode feedback sub-circuit; When any zero-stabilizing input stage in the fully differential input stage is configured to be in the zero-stabilizing calibration working state, the working state of the switching switch in the zero-stabilizing calibration switching switch group is configured at the same time, so that the zero-stabilizing calibration common-mode feedback sub-circuit is adaptively connected to the zero-stabilizing input stage in the zero-stabilizing calibration working state, and the zero-stabilizing calibration common-mode feedback sub-circuit is used to stabilize the zero-stabilizing calibration common-mode voltage output by the connected zero-stabilizing input stage.

10. The ripple elimination method of the auto-zero amplifier according to claim 8, characterized in that: The zero-stabilization calibration common-mode feedback section includes two zero-stabilization calibration common-mode feedback sub-circuits and a second zero-stabilization calibration switching switch group adapted to the zero-stabilization calibration common-mode feedback sub-circuits, wherein the zero-stabilization calibration common-mode feedback sub-circuits are in one-to-one correspondence with the zero-stabilization input stages; When any zero-stable input stage in the fully differential input stage is configured to be in the zero-stable calibration working state, the working state of the switch in the second zero-stable calibration switch group is also configured at the same time, so that the zero-stable input stage is adaptively connected to the corresponding zero-stable calibration common-mode feedback sub-circuit.

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