A method and apparatus for testing an instrumentation amplifier offset voltage

Abstract

The application discloses a kind of instrument amplifier misadjustment voltage test method and device, it is related to amplifier (or integrated circuit) test technical field, method includes: by standard instrument amplifier and the measured instrument amplifier form group, test sets up standard instrument amplifier and the two groups of gain of measured instrument amplifier group body two total misadjustment voltages, namely accurate test instrument amplifier input misadjustment voltage and output misadjustment voltage can be realized, device includes: first condition applying module, first total misadjustment voltage acquisition module, second condition applying module, second total misadjustment voltage acquisition module, first calculation module, second calculation module, third calculation module, output module.This method and device can obtain higher test precision result with lower test resource requirement, can carry out automatic test.

Description

Technical Field

[0001] This invention relates to the field of amplifier (or integrated circuit) testing technology, and more specifically to a method and apparatus for testing the offset voltage of an instrumentation amplifier. Background Technology

[0002] The offset voltage of an instrumentation amplifier is divided into input offset voltage and output offset voltage. Generally, it is achieved by approximating the input offset voltage with the total offset voltage, or by solving the equation by measuring two sets of total offset voltages under different gain conditions.

[0003] Existing approximate replacement methods have very low accuracy and cannot accurately test the input and output offset voltages. Existing methods for testing two sets of total offset voltages under different gain conditions require high precision test instruments and are not convenient for automated testing. Summary of the Invention

[0004] This invention provides a method and apparatus for testing the offset voltage of an instrumentation amplifier, comprising:

[0005] A first matching condition is applied to the assemblies including the instrumentation amplifier under test and a standard instrumentation amplifier of the same model as the instrumentation amplifier under test. The first matching condition is that the gain value of the instrumentation amplifier under test is a first value and the gain value of the standard instrumentation amplifier is a second value; the product of the first value and the second value is a fixed value.

[0006] Under the first pairing condition, obtain the first standard total offset voltage of the standard instrumentation amplifier and the first total offset voltage of the pairing ligands;

[0007] A second combination condition is applied to the ligand, wherein the gain value of the instrumentation amplifier under test is a second value, and the gain value of the standard instrumentation amplifier is a first value.

[0008] Under the second grouping condition, obtain the second standard total offset voltage of the standard instrumentation amplifier and the second grouping total offset voltage of the grouping ligands;

[0009] Based on the predetermined offset voltage relationship of the internal components of the ligand, the second value, the first standard total offset voltage of the standard instrumentation amplifier, and the first total offset voltage of the ligand, the first total offset voltage of the instrumentation amplifier under test is determined under the first ligand condition.

[0010] Based on the offset voltage relationship, the first value, the second standard total offset voltage of the standard instrumentation amplifier, and the second group ligand total offset voltage of the group ligand, the second measured total offset voltage of the instrumentation amplifier under test under the second group ligand condition is determined.

[0011] Based on the first and second measured total offset voltages, the input and output offset voltages of the instrumentation amplifier under test are determined.

[0012] Optionally, before determining the input offset voltage and output offset voltage of the instrumentation amplifier under test based on the first measured total offset voltage and the second measured total offset voltage, the following steps are included:

[0013] Using a predetermined first conversion relationship, the first equation relationship between the offset voltage of the instrument amplifier under test and the first total offset voltage under test, and the second equation relationship between the offset voltage of the instrument amplifier under test and the second total offset voltage under test are determined.

[0014] The conversion formula is the conversion relationship between the total offset voltage of the amplifier under test and the input offset voltage, output offset voltage, and gain of the amplifier under test.

[0015] Optionally, based on the first and second measured total offset voltages, the input and output offset voltages of the instrumentation amplifier under test are determined, including:

[0016] Substituting the first measured total offset voltage and the second measured total offset voltage into the first equation and the second equation respectively, we obtain the input offset voltage and output offset voltage of the instrumentation amplifier under test.

[0017] Optionally, the ligand linkage method is as follows:

[0018] The input terminal of the standard instrumentation amplifier is the input terminal of the ligand; the output terminal of the standard instrumentation amplifier is connected to the non-inverting input terminal of the instrumentation amplifier under test; the inverting input terminal of the instrumentation amplifier under test is connected to the ground terminal; and the output terminal of the instrumentation amplifier under test is the output terminal of the ligand.

[0019] The negative power supply terminals of the standard instrumentation amplifier and the instrumentation amplifier under test are connected to the positive power supply terminal of the first power supply, and the positive power supply terminals of the standard instrumentation amplifier and the instrumentation amplifier under test are connected to the negative power supply terminal of the first power supply.

[0020] Optionally, the ligand is placed in the test circuit, in which:

[0021] The inverting input terminal of the ligand is connected to the first terminal of the first resistor, the non-inverting input terminal of the ligand is connected to the first terminal of the second resistor, the second terminals of the first resistor and the second resistor are respectively connected to the ground terminal; the output terminal of the ligand is connected to the first terminal of the third resistor, the second terminal of the third resistor is connected to the first terminal of the fourth resistor, and the second terminal of the fourth resistor is connected to the reference voltage terminal.

[0022] The test circuit also includes an auxiliary operational amplifier. The positive input terminal of the auxiliary operational amplifier is connected to the second terminal of the third resistor, the negative input terminal of the auxiliary operational amplifier is connected to the ground terminal, the output terminal of the auxiliary operational amplifier is connected to the first terminal of the fifth resistor, and the second terminal of the fifth resistor is connected to the negative input terminal of the ligand. The output terminal of the auxiliary operational amplifier is the output terminal of the circuit.

[0023] The negative power supply terminal of the auxiliary operational amplifier is connected to the positive power supply terminal of the second power supply, and the positive power supply terminal of the auxiliary operational amplifier is connected to the negative power supply terminal of the second power supply.

[0024] The present invention also provides an instrumentation amplifier offset voltage testing device, the device comprising:

[0025] The first condition application module is used to apply a first combination condition to the ligand including the instrument amplifier under test and a standard instrument amplifier of the same model as the instrument amplifier under test. The first combination condition is that the gain value of the instrument amplifier under test is a first value and the gain value of the standard instrument amplifier is a second value. The product of the first value and the second value is always a fixed value.

[0026] The first group of ligand total offset voltage acquisition module is used to acquire the first standard total offset voltage of the standard instrumentation amplifier and the first group of ligand total offset voltage of the group of ligands under the first group of ligand conditions.

[0027] The second condition application module applies a second combination condition to the ligand. The second combination condition is that the gain value of the tested instrument amplifier is a second value, and the gain value of the standard instrument amplifier is a first value.

[0028] The second group of ligand total offset voltage acquisition module acquires the second standard total offset voltage of the standard instrumentation amplifier and the second group of ligand total offset voltage under the second group of ligand conditions.

[0029] The first calculation module determines the first total offset voltage of the instrumentation amplifier under test under the first pairing condition based on the predetermined offset voltage relationship of the internal components of the ligand, the second value, the first standard total offset voltage of the standard instrumentation amplifier, and the first total offset voltage of the ligand.

[0030] The second calculation module determines the second total offset voltage of the instrumentation amplifier under test under the second grouping condition based on the offset voltage relationship, the first value, the second standard total offset voltage of the standard instrumentation amplifier, and the second group ligand total offset voltage of the group ligand.

[0031] The output module determines the input offset voltage and output offset voltage of the instrumentation amplifier under test based on the first and second measured total offset voltages.

[0032] Optionally, the device also includes:

[0033] The third calculation module uses a predetermined first conversion relationship to determine the first equation relationship between the offset voltage of the instrument amplifier under test and the first total offset voltage under test, and the second equation relationship between the offset voltage of the instrument amplifier under test and the second total offset voltage under test.

[0034] The conversion formula is the conversion relationship between the total offset voltage of the amplifier under test and the input offset voltage, output offset voltage, and gain of the amplifier under test.

[0035] Optionally, the third calculation module is also used for:

[0036] Substituting the first measured total offset voltage and the second measured total offset voltage into the first equation and the second equation respectively, we obtain the input offset voltage and output offset voltage of the instrumentation amplifier under test.

[0037] The present invention also provides an electronic device, which includes a processor and a memory. The memory stores at least one instruction, at least one program, code set or instruction set. The processor loads and executes the at least one instruction, at least one program, code set or instruction set to implement the instrumentation amplifier offset voltage test method.

[0038] The present invention also provides a computer-readable storage medium storing at least one instruction, at least one program, code set, or instruction set, wherein the at least one instruction, at least one program, code set, or instruction set is loaded and executed by a processor to implement an instrumentation amplifier offset voltage test method.

[0039] This invention provides a method and apparatus for testing the offset voltage of an instrumentation amplifier, which has the following advantages compared with the prior art:

[0040] This invention uses a standard instrumentation amplifier and the instrumentation amplifier under test to form a set of ligands. By testing the two total offset voltages of the set ligands under the two sets of gains of the standard instrumentation amplifier and the instrumentation amplifier under test, it is possible to accurately test the input offset voltage and output offset voltage of the instrumentation amplifier. This implementation method can be conveniently extended to the testing of other parameters of the instrumentation amplifier, such as common-mode rejection ratio, power supply rejection ratio, and gain. The accuracy of the test instruments required for accurately testing the input offset voltage and output offset voltage of the instrumentation amplifier is reduced, and automated testing can be achieved more conveniently. Attached Figure Description

[0041] To more clearly illustrate the technical solutions of the present invention, the accompanying drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0042] Figure 1 A flowchart of an instrumentation amplifier offset voltage testing method provided in an embodiment of the present invention;

[0043] Figure 2 A circuit structure diagram of a ligand provided in an embodiment of the present invention;

[0044] Figure 3 A test circuit structure diagram provided in an embodiment of the present invention;

[0045] Figure 4 This is a structural block diagram of an instrumentation amplifier offset voltage testing device provided in an embodiment of the present invention. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] This specification provides the operational steps of the methods described in the embodiments or flowcharts, but may include more or fewer operational steps based on conventional or non-inventive labor. In actual circuit or server products, the methods shown in the embodiments or drawings may be executed sequentially or in parallel (e.g., in a parallel processor or multi-threaded processing environment).

[0048] Figure 1 This is a flowchart of a method for testing the offset voltage of an instrumentation amplifier, including:

[0049] Step 101: Apply a first matching condition to the assembly including the instrumentation amplifier under test and a standard instrumentation amplifier of the same model as the instrumentation amplifier under test. The first matching condition is that the gain value of the instrumentation amplifier under test is a first value and the gain value of the standard instrumentation amplifier is a second value; the product of the first value and the second value is a fixed value.

[0050] The instrumentation amplifier under test (AAT) is an instrumentation amplifier with an adjustable gain range, typically between 1 and 1000. The AAT and the instrumentation amplifier under test are assembled into a fixed-gain, maximum-gain combination. An AAT of the same model as the AAT is selected, and its total input offset voltage, input offset voltage, output offset voltage, gain, and other related parameters are accurately tested and calibrated. The AAT is an instrumentation amplifier whose various performance deviations are within specified ranges. For ease of calculation and accuracy, a fixed gain of 1000 is chosen for the combination. The first assembly condition includes the gains of the standard AAT and the AAT being measured as G'=1000 and G=1, respectively. Selecting the maximum and minimum gains of the standard AAT and the AAT being measured is to maximize or minimize their ratio, thus minimizing the impact on calculation accuracy and ensuring the most accurate measurement of the AAT's offset voltage.

[0051] Step 102: Obtain the first standard total offset voltage of the standard instrumentation amplifier and the first total offset voltage of the group ligands under the first group ligand conditions;

[0052] The first total offset voltage of a standard instrumentation amplifier is obtained through calibration, while the first total offset voltage of a group of ligands is obtained through a test circuit. Offset voltage includes input offset voltage and output offset voltage. Input offset voltage refers to the difference in DC voltage applied to the two input terminals of a differential amplifier or differential-input operational amplifier in order to obtain a constant zero-voltage output. This parameter characterizes the matching degree of this stage of the differential amplifier. When equal input voltages are applied to the two input terminals of the differential amplifier, the differential output voltage is called the output offset voltage. Offset voltage is one of the most important parameters of an operational amplifier. An operational amplifier consists of numerous transistors, with two (for design consistency) transistors forming the first differential input stage. However, due to inconsistent doping processes of the transistors, transistor parameters vary, resulting in diverse electrical characteristics under the same conditions, ultimately leading to offset voltage. The total offset voltage is the sum of all offset voltages of the instrumentation amplifier. Total offset voltage can be measured using general test circuits and methods, such as the total offset voltage of ligand and standard instrumentation amplifiers, which can be measured using the "Basic Principles of Test Methods for Operational (Voltage) Amplifiers of Semiconductor Integrated Circuits".

[0053] Step 103: Apply a second combination condition to the ligand. The second combination condition is that the gain value of the tested instrument amplifier is a second value, and the gain value of the standard instrument amplifier is a first value.

[0054] The second set of matching conditions includes the gains of the standard instrument amplifier and the instrument amplifier under test being G'=1 and G=1000, respectively. Similarly, the maximum and minimum values ​​of the gains of the standard instrument amplifier and the instrument amplifier under test are selected to maximize or minimize the ratio between the two, thereby minimizing the impact on the accuracy of the calculation and thus most accurately measuring the offset voltage of the instrument amplifier under test.

[0055] Step 104: Obtain the second standard total offset voltage of the standard instrumentation amplifier and the second total offset voltage of the group ligands under the second group ligand conditions;

[0056] With the same set of ligands, the gain of the standard instrumentation amplifier and the instrumentation amplifier under test is adjusted. By interchangering the gain of the standard instrumentation amplifier and the instrumentation amplifier under test on the same set of ligands, the second total offset voltage of the second set of ligands and the standard instrumentation amplifier is obtained. Here, the total offset voltage of the standard instrumentation amplifier is constant and can be found in its relevant parameters after calibration.

[0057] Step 105: Based on the predetermined offset voltage relationship of the internal components of the ligand, the second value, the first standard total offset voltage of the standard instrumentation amplifier, and the first total offset voltage of the ligand, determine the first total offset voltage of the instrumentation amplifier under test under the first ligand condition.

[0058] The predetermined offset voltage relationship of the internal components of the ligand is Vos = (VosT - Vos') × G'; where Vos is the total offset voltage of the instrumentation amplifier under test, Vos' is the total offset voltage of the standard instrumentation amplifier, VosT is the total offset voltage of the ligand, and G' is the gain of the standard instrumentation amplifier; in the offset voltage relationship, the second value of the gain G' of the standard instrumentation amplifier (1000), the first standard total offset voltage of the standard instrumentation amplifier, and the first total offset voltage of the ligand are input, and the first total offset voltage of the ligand is output as the first total offset voltage Vos1 of the instrumentation amplifier under test under the first ligand condition is output.

[0059] Step 106: Based on the offset voltage relationship, the first value, the second standard total offset voltage of the standard instrumentation amplifier, and the second group ligand total offset voltage of the group ligand, determine the second total offset voltage of the instrumentation amplifier under test under the second group ligand condition;

[0060] Using the same formula as the previous step, input the first value 1 of the gain of the standard instrumentation amplifier, the second standard total offset voltage of the standard instrumentation amplifier, and the second total offset voltage of the group ligand, and output the second total offset voltage Vos2 of the instrumentation amplifier under test under the second group ligand condition.

[0061] Step 107: Based on the first total offset voltage Vos1 and the second total offset voltage Vos2, determine the input offset voltage and output offset voltage of the instrumentation amplifier under test.

[0062] By substituting the total offset voltages of the first and second instrumentation amplifiers under the first and second ligand conditions, along with the gains of the two relevant standard instrumentation amplifiers, into Vos = (VosT - Vos') × G', we can solve for the input offset voltage, which equals the second total offset voltage of the ligand group, and the output offset voltage, which equals the second total offset voltage of the ligand group minus the first total offset voltage. Thus, by appropriately setting the gain parameters of the ligand group, accurate input and output offset voltages of the measuring instrumentation amplifier can be obtained.

[0063] In summary, this invention uses a standard instrumentation amplifier and the instrumentation amplifier under test to form a ligand. By testing the two total offset voltages of the ligands under two sets of gains for the standard instrumentation amplifier and the instrumentation amplifier under test, it is possible to accurately test the input and output offset voltages of the instrumentation amplifier. This implementation method can be conveniently extended to the testing of other parameters of the instrumentation amplifier, such as common-mode rejection ratio, power supply rejection ratio, and gain. The accuracy of the test instruments required for accurately testing the input and output offset voltages of the instrumentation amplifier is reduced, and automated testing can be achieved more conveniently.

[0064] In one possible implementation, before determining the input offset voltage and output offset voltage of the instrumentation amplifier under test based on the first total offset voltage and the second total offset voltage, the method further includes:

[0065] Step 201: Using a predetermined first conversion relationship, determine the first equation relationship between the offset voltage of the instrument amplifier under test and the first total offset voltage under test, and the second equation relationship between the offset voltage of the instrument amplifier under test and the second total offset voltage under test;

[0066] The offset voltage of the instrumentation amplifier under test is taken as an unknown parameter. The gain G=1 of the instrumentation amplifier under test under the first set of matching conditions and the first total offset voltage Vos1 corresponding to the gain of the standard instrumentation amplifier under the first set of matching conditions are taken as the first set of known quantities in the relation. The gain G=1000 of the instrumentation amplifier under test under the second set of matching conditions and the second total offset voltage Vos2 corresponding to the gain of the standard instrumentation amplifier under the second set of matching conditions are taken as the second set of known quantities in the relation.

[0067] Step 202: The conversion formula is the conversion formula between the total offset voltage of the amplifier under test and the input offset voltage, the output offset voltage, and the gain of the amplifier under test.

[0068] The transformation formulas include: Vos = VosI + Voso / G;

[0069] Where VosI represents the input offset voltage of the amplifier under test, Voso represents the output offset voltage of the amplifier under test, and G represents the gain of the amplifier under test.

[0070] In one possible implementation, determining the input offset voltage and output offset voltage of the instrumentation amplifier under test based on a first measured total offset voltage and a second measured total offset voltage includes:

[0071] Step 301: Substitute the first measured total offset voltage and the second measured total offset voltage into the first equation and the second equation, respectively, to obtain the input offset voltage and output offset voltage of the instrumentation amplifier under test.

[0072] The values ​​of VosI and Voso are obtained from two sets of known quantities, Vos1 and Vos2, two unknown quantities, VosI and Voso, and the transformation formula.

[0073] Specifically, VosI = 1000 / 999 × Vos1 - Vos2 / 999 ≈ 1.001 × Vos1 - 0.001 × Vos2;

[0074] Voso=1000 / 999×(Vos2- Vos1)≈1.001×(Vos2- Vos1).

[0075] In summary, the input and output offset voltages of the instrumentation amplifier under test can be obtained by acquiring the first and second total offset voltages. Furthermore, the first and second total offset voltages can be obtained by measuring the total offset voltage Vos' of the standard instrumentation amplifier, the total offset voltage VosT of the ligand, the gain G' of the standard instrumentation amplifier, and the relationship Vos = (VosT - Vos') × G'. Therefore, the accurate input and output offset voltages of the instrumentation amplifier under test can be obtained through the above methods.

[0076] In one possible implementation, the ligands are linked as follows:

[0077] The input terminal of the standard instrumentation amplifier is the input terminal of the ligand; the output terminal of the standard instrumentation amplifier is connected to the non-inverting input terminal of the instrumentation amplifier under test; the inverting input terminal of the instrumentation amplifier under test is connected to the ground terminal; and the output terminal of the instrumentation amplifier under test is the output terminal of the ligand.

[0078] The negative power supply terminals of the standard instrumentation amplifier and the instrumentation amplifier under test are connected to the positive power supply terminal of the first power supply, and the positive power supply terminals of the standard instrumentation amplifier and the instrumentation amplifier under test are connected to the negative power supply terminal of the first power supply.

[0079] Specifically, Figure 2 The circuit structure diagram of a ligand provided in an embodiment of the present invention is shown.

[0080] like Figure 2 As shown, in the embodiment provided by the present invention, the input terminal of the ligand 300 adopts the input terminal of the standard instrumentation amplifier 100, the output terminal of the standard instrumentation amplifier 100 is connected to the non-inverting input terminal of the instrumentation amplifier under test 200, the output terminal of the instrumentation amplifier under test 200 is used as the output terminal of the ligand 300, the inverting input terminal of the instrumentation amplifier under test 200 is grounded, the negative power supply terminal of the ligand 300 is connected to the common positive power supply connection terminal of the standard instrumentation amplifier 100 and the instrumentation amplifier under test 200, and the positive power supply of the ligand is connected to the common negative power supply connection terminal of the standard instrumentation amplifier 100 and the instrumentation amplifier under test 200.

[0081] In summary, this invention combines the device under test and a standard instrumentation amplifier of the same model into a ligand, simplifying complex test programs into universal test programs.

[0082] In one possible implementation, the ligand is disposed in a test circuit in which the inverting input terminal of the ligand is connected to the first terminal of a first resistor, the non-inverting input terminal of the ligand is connected to the first terminal of a second resistor, the second terminals of the first and second resistors are respectively connected to a ground terminal; the output terminal of the ligand is connected to the first terminal of a third resistor, the second terminal of the third resistor is connected to the first terminal of a fourth resistor, and the second terminal of the fourth resistor is connected to a reference voltage terminal.

[0083] The circuit also includes an auxiliary operational amplifier. The positive input terminal of the auxiliary operational amplifier is connected to the second terminal of the third resistor, the negative input terminal of the auxiliary operational amplifier is connected to the ground terminal, the output terminal of the auxiliary operational amplifier is connected to the first terminal of the fifth resistor, and the second terminal of the fifth resistor is connected to the negative input terminal of the ligand. The output terminal of the auxiliary operational amplifier is the output terminal of the circuit.

[0084] The negative power supply terminal of the auxiliary operational amplifier is connected to the positive power supply terminal of the second power supply, and the positive power supply terminal of the auxiliary operational amplifier is connected to the negative power supply terminal of the second power supply.

[0085] Figure 3This is a structural diagram of a test circuit provided for an embodiment of the present invention.

[0086] Specifically, such as Figure 3 As shown, in an embodiment of the present invention, the non-inverting and inverting input terminals of the ligand 300 are connected in series with the first resistor R1 and the second resistor R2, respectively, and then grounded; the output terminal of the ligand 300 is connected in series with the third resistor R3 and then connected to the non-inverting input terminal of the auxiliary operational amplifier 400; the non-inverting input terminal of the auxiliary operational amplifier 400 is connected to the fourth resistor R4, and the other end of the fourth resistor R4 is connected to the reference point; the inverting input terminal of the auxiliary operational amplifier 400 is grounded; the output terminal of the auxiliary operational amplifier 400 is connected to the inverting input terminal of the ligand 300 through the fourth resistor RF; wherein, R1=R2. The output terminal of the auxiliary operational amplifier 400 is the output terminal of the test circuit, and the voltage at the output terminal is V. L The negative power supply terminal of the auxiliary operational amplifier 400 is connected to the positive power supply terminal, and the positive power supply terminal of the auxiliary operational amplifier 400 is connected to the negative power supply terminal. According to the "Basic Principles of Test Methods for Operational (Voltage) Amplifiers in Semiconductor Integrated Circuits,"... , where vos is the total offset voltage of group ligand 300.

[0087] In summary, the method for testing the offset voltage of instrumentation amplifiers using a general-purpose test system and method is simple and easy to implement.

[0088] Figure 4 This is a structural block diagram of an instrumentation amplifier offset voltage testing device provided in an embodiment of the present invention. Figure 4 As shown, the device 500 includes:

[0089] The first condition application module 501 is used to apply a first combination condition to a combination assembly including the instrument amplifier under test and a standard instrument amplifier of the same model as the instrument amplifier under test. The first combination condition is that the gain value of the instrument amplifier under test is a first value and the gain value of the standard instrument amplifier is a second value. The product of the first value and the second value is always a fixed value.

[0090] The first group ligand total offset voltage acquisition module 502 is used to acquire the first standard total offset voltage of the standard instrumentation amplifier and the first group ligand total offset voltage of the group ligand under the first group ligand condition.

[0091] The second condition application module 503 applies a second combination condition to the ligand, wherein the second combination condition is that the gain value of the tested instrument amplifier is the second value, and the gain value of the standard instrument amplifier is the first value.

[0092] The second group of ligand total offset voltage acquisition module 504 acquires the second total offset voltage of the standard instrumentation amplifier and the second total offset voltage of the group of ligands under the second group of ligand conditions.

[0093] The first calculation module 505 determines the first total offset voltage of the instrument amplifier under test under the first combination condition based on the predetermined offset voltage relationship of the internal components of the ligand, the second value, the first standard total offset voltage of the standard instrument amplifier, and the first total offset voltage of the ligand.

[0094] The second calculation module 506 determines the second total offset voltage of the instrumentation amplifier under the second grouping condition based on the offset voltage relationship, the first value, the second standard total offset voltage of the standard instrumentation amplifier, and the second grouping total offset voltage of the grouping ligands.

[0095] The output module 508 determines the input offset voltage and output offset voltage of the instrumentation amplifier under test based on the first measured total offset voltage and the second measured total offset voltage.

[0096] In one possible implementation, the device further includes:

[0097] The third calculation module 507 uses a predetermined first conversion relationship to determine the first equation relationship between the offset voltage of the instrument amplifier under test and the first total offset voltage under test, and the second equation relationship between the offset voltage of the instrument amplifier under test and the second total offset voltage under test.

[0098] The conversion formula is the conversion relationship between the total offset voltage of the amplifier under test and the input offset voltage, the output offset voltage, and the gain of the amplifier under test.

[0099] In one possible implementation, the third computing module 507 is further configured to:

[0100] Substituting the first measured total offset voltage and the second measured total offset voltage into the first equation and the second equation respectively, the input offset voltage and output offset voltage of the instrumentation amplifier under test are obtained.

[0101] In a possible embodiment of the present invention, a device is also provided, the device including a processor and a memory, the memory storing at least one instruction, at least one program, code set or instruction set, the at least one instruction, the at least one program, the code set or instruction set being loaded and executed by the processor to implement the point cloud data visualization processing method described in the embodiments of the present invention.

[0102] In a possible embodiment of the present invention, a computer-readable storage medium is also provided, wherein at least one instruction, at least one program, code set or instruction set is stored in the storage medium, and the at least one instruction, the at least one program, the code set or instruction set is loaded and executed by a processor to implement the point cloud data visualization processing method described in the embodiments of the present invention.

[0103] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present invention are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0104] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0105] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the circuit embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0106] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A method for testing the offset voltage of an instrumentation amplifier, characterized in that, The method includes: A first fitting condition is applied to a assemblies comprising an instrumentation amplifier under test and a standard instrumentation amplifier of the same model as the instrumentation amplifier under test. The first fitting condition is that the gain value of the instrumentation amplifier under test is a first value, and the gain value of the standard instrumentation amplifier is a second value; the product of the first value and the second value is a fixed value. Under the first pairing conditions, obtain the first standard total offset voltage of the standard instrumentation amplifier and the first total offset voltage of the pairing ligands; A second combination condition is applied to the ligand, wherein the gain value of the instrumentation amplifier under test is the second value, and the gain value of the standard instrumentation amplifier is the first value; Under the second grouping condition, obtain the second standard total offset voltage of the standard instrumentation amplifier and the second grouping total offset voltage of the grouping ligand; Based on the predetermined offset voltage relationship of the internal components of the ligand, the second value, the first standard total offset voltage of the standard instrumentation amplifier, and the first total offset voltage of the ligand, the first total offset voltage of the instrumentation amplifier under test is determined under the first ligand condition. Based on the offset voltage relationship, the first value, the second standard total offset voltage of the standard instrumentation amplifier, and the second group ligand total offset voltage of the group ligand, the second total offset voltage of the instrumentation amplifier under test is determined under the second group ligand condition; Based on the first measured total offset voltage and the second measured total offset voltage, the input offset voltage and output offset voltage of the instrumentation amplifier under test are determined.

2. The method according to claim 1, characterized in that, Before determining the input offset voltage and output offset voltage of the instrumentation amplifier under test based on the first measured total offset voltage and the second measured total offset voltage, the process includes: Using a predetermined first conversion relationship, a first equation relationship between the offset voltage of the instrument amplifier under test and the first total offset voltage under test, and a second equation relationship between the offset voltage of the instrument amplifier under test and the second total offset voltage under test are determined. The conversion formula is the conversion relationship between the total offset voltage of the instrumentation amplifier under test and the input offset voltage, the output offset voltage, and the gain of the instrumentation amplifier under test.

3. The method according to claim 2, characterized in that, The step of determining the input offset voltage and output offset voltage of the instrumentation amplifier under test based on the first measured total offset voltage and the second measured total offset voltage includes: Substituting the first measured total offset voltage and the second measured total offset voltage into the first equation and the second equation respectively, the input offset voltage and output offset voltage of the instrumentation amplifier under test are obtained.

4. The method according to claim 1, characterized in that, The connection method of the ligands is as follows: The input terminal of the standard instrumentation amplifier is the input terminal of the group ligand; the output terminal of the standard instrumentation amplifier is connected to the non-inverting input terminal of the instrumentation amplifier under test; the inverting input terminal of the instrumentation amplifier under test is connected to the ground terminal; and the output terminal of the instrumentation amplifier under test is the output terminal of the group ligand. The negative power supply terminals of the standard instrumentation amplifier and the instrumentation amplifier under test are connected to the positive power supply terminal of the first power supply, and the positive power supply terminals of the standard instrumentation amplifier and the instrumentation amplifier under test are connected to the negative power supply terminal of the first power supply.

5. The method according to any one of claims 1-4, characterized in that, The ligand is disposed in a test circuit, in which: The inverting input terminal of the ligand is connected to the first terminal of the first resistor, the non-inverting input terminal of the ligand is connected to the first terminal of the second resistor, the second terminals of the first resistor and the second resistor are respectively connected to the ground terminal; the output terminal of the ligand is connected to the first terminal of the third resistor, the second terminal of the third resistor is connected to the first terminal of the fourth resistor, and the second terminal of the fourth resistor is connected to the reference voltage terminal. The test circuit also includes an auxiliary operational amplifier. The positive input terminal of the auxiliary operational amplifier is connected to the second terminal of the third resistor, the negative input terminal of the auxiliary operational amplifier is connected to the ground terminal, the output terminal of the auxiliary operational amplifier is connected to the first terminal of the fifth resistor, and the second terminal of the fifth resistor is connected to the negative input terminal of the ligand group. The output terminal of the auxiliary operational amplifier is the output terminal of the circuit. The negative power supply terminal of the auxiliary operational amplifier is connected to the positive power supply terminal of the second power supply, and the positive power supply terminal of the auxiliary operational amplifier is connected to the negative power supply terminal of the second power supply.

6. A device for testing the offset voltage of an instrumentation amplifier, characterized in that, The device includes: The first condition application module is used to apply a first combination condition to a combination assembly including the instrumentation amplifier under test and a standard instrumentation amplifier of the same model as the instrumentation amplifier under test. The first combination condition is that the gain value of the instrumentation amplifier under test is a first value, and the gain value of the standard instrumentation amplifier is a second value. The product of the first value and the second value is always a fixed value. The first group of ligand total offset voltage acquisition module is used to acquire the first standard total offset voltage of the standard instrumentation amplifier and the first group of ligand total offset voltage of the group of ligands under the first group of ligands conditions. The second condition application module applies a second combination condition to the ligand, wherein the second combination condition is that the gain value of the tested instrument amplifier is the second value, and the gain value of the standard instrument amplifier is the first value. The second group of ligand total offset voltage acquisition module acquires the second standard total offset voltage of the standard instrumentation amplifier and the second group of ligand total offset voltage of the group of ligands under the second group of ligand conditions. The first calculation module determines the first total offset voltage of the instrument amplifier under test under the first combination condition based on the predetermined offset voltage relationship of the internal components of the ligand, the second value, the first standard total offset voltage of the standard instrument amplifier, and the first total offset voltage of the ligand. The second calculation module determines the second total offset voltage of the instrumentation amplifier under the second grouping condition based on the offset voltage relationship, the first value, the second standard total offset voltage of the standard instrumentation amplifier, and the second grouping total offset voltage of the grouping ligands. The output module determines the input offset voltage and output offset voltage of the instrumentation amplifier under test based on the first measured total offset voltage and the second measured total offset voltage.

7. The apparatus according to claim 6, characterized in that, The device further includes: The third calculation module uses a predetermined first conversion relationship to determine the first equation relationship between the offset voltage of the instrument amplifier under test and the first total offset voltage under test, and the second equation relationship between the offset voltage of the instrument amplifier under test and the second total offset voltage under test. The conversion formula is the conversion relationship between the total offset voltage of the instrumentation amplifier under test and the input offset voltage, the output offset voltage, and the gain of the instrumentation amplifier under test.

8. The apparatus according to claim 7, characterized in that, The third calculation module is also used for: Substituting the first measured total offset voltage and the second measured total offset voltage into the first equation and the second equation respectively, the input offset voltage and output offset voltage of the instrumentation amplifier under test are obtained.

9. An electronic device, characterized in that, The electronic device includes a processor and a memory, wherein the memory stores at least one instruction, at least one program, code set, or instruction set, and the at least one instruction, the at least one program, the code set, or the instruction set is loaded and executed by the processor to implement the instrumentation amplifier offset voltage test method as described in any one of claims 1-5.

10. A computer-readable storage medium, characterized in that, The storage medium stores at least one instruction, at least one program, code set, or instruction set, wherein the at least one instruction, the at least one program, the code set, or instruction set is loaded and executed by a processor to implement the instrumentation amplifier offset voltage test method as described in any one of claims 1-5.

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