CN107966615B - Integrated operational amplifier open loop amplitude-frequency characteristic test system - Google Patents
Integrated operational amplifier open loop amplitude-frequency characteristic test system Download PDFInfo
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- CN107966615B CN107966615B CN201711265871.6A CN201711265871A CN107966615B CN 107966615 B CN107966615 B CN 107966615B CN 201711265871 A CN201711265871 A CN 201711265871A CN 107966615 B CN107966615 B CN 107966615B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/28—Measuring attenuation, gain, phase shift or derived characteristics of electric four pole networks, i.e. two-port networks; Measuring transient response
- G01R27/30—Measuring attenuation, gain, phase shift or derived characteristics of electric four pole networks, i.e. two-port networks; Measuring transient response with provision for recording characteristics, e.g. by plotting Nyquist diagram
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R23/00—Arrangements for measuring frequencies; Arrangements for analysing frequency spectra
- G01R23/16—Spectrum analysis; Fourier analysis
Abstract
The invention discloses an integrated operational amplifier open-loop amplitude-frequency characteristic test system. The method comprises the steps that a negative input end A of an integrated operational amplifier to be tested, one end of a resistor R1, one end of a resistor R2 and a negative input end C of a low-noise preamplifier are connected together, the other end of a resistor R1 is connected with a channel 0 of a data acquisition card, the other end of the resistor R2, an amplified output signal Vo1 of the integrated operational amplifier to be tested and a channel 1 of the data acquisition card are connected together, a positive input end B of the integrated operational amplifier to be tested is grounded, a positive input end D of the low-noise preamplifier is grounded, an output end Vo2 of the low-noise preamplifier is connected with a channel 2 of the data acquisition card, the data acquisition card is connected with a computer, data acquired by the data acquisition card is provided for the computer, and signal cross-correlation analysis processing software in the computer is used for analyzing. The invention has the advantages of simple structure of the testing device, high precision, wide testing range and visual reading.
Description
Technical Field
The invention belongs to the technical field of amplifier amplitude-frequency characteristic testing, and relates to an integrated operational amplifier open-loop amplitude-frequency characteristic testing system.
Background
In various activities of engineering technology, scientific research and production practice, the test of the amplitude-frequency characteristic of the integrated operational amplifier open loop has very important significance. According to the definition of the open-loop gain, the most direct measurement method is to directly measure the input voltage Vi and the amplified output voltage Vo of the input end of the integrated operational amplifier under the condition of the open loop of the integrated operational amplifier. The open loop gain is: Vo/Vi. Since Vi is in uV order, it can not be measured by common millivoltmeter, and can be easily measured by cross-correlation method. When the operational amplifier is integrated into an open loop, the working state is likely to be unstable due to the large amplification factor, and the offset voltage, the offset current, the drift and the like are considered. Therefore, under the closed-loop condition, the measurement of the open-loop gain can be carried out, and a plurality of defects in the open-loop measurement can be eliminated.
With the continuous development of scientific technology and the updating of the technical content of weak signal detection, the traditional instruments increasingly expose some defects and shortcomings, and the instruments cannot meet the requirements of modern electronic measurement and seriously affect teaching and scientific research. In order to improve the level and method of electronic measurement, a virtual instrument is introduced into an integrated operational amplifier open-loop amplitude-frequency characteristic detection technology and applied to a modern electronic measurement subject to solve the problem of specific electronic circuit measurement. The virtual instrument can save a large amount of investment of instruments and equipment, improve the quality and efficiency of teaching and scientific research, and realize the content that a common instrument cannot directly measure or cannot accurately measure. The invention measures the open-loop amplitude-frequency characteristic of the integrated operational amplifier by using a virtual instrument technology and a software cross-correlation detection method, and has the advantages of simple structure, low cost, high test automation degree and the like.
Disclosure of Invention
The invention aims to provide an integrated operational amplifier open-loop amplitude-frequency characteristic test system.
The technical scheme includes that the integrated operational amplifier to be tested comprises an integrated operational amplifier to be tested, a negative input end A of the integrated operational amplifier to be tested, one end of a resistor R1, one end of a resistor R2 and a negative input end C of a low-noise preamplifier are connected together, the other end of a resistor R1 is connected with a channel 0 of a data acquisition card, the other end of the resistor R2, an amplified output signal Vo1 of the integrated operational amplifier to be tested and a channel 1 of the data acquisition card are connected together, a positive input end B of the integrated operational amplifier to be tested is grounded, a positive input end D of the low-noise preamplifier is grounded, an output end Vo2 of the low-noise preamplifier is connected with a channel 2 of the data acquisition card, the data acquisition card is connected with a computer, data acquired by the data acquisition card is provided for the computer, and signal cross-correlation analysis processing software in the computer is used for.
Furthermore, the positive input end B of the integrated operational amplifier to be tested is connected with the ground end of the direct current power supply, the positive input end D of the low-noise preamplifier is connected with the ground end of the direct current power supply, and the direct current power supply is connected with the integrated operational amplifier to be tested and the low-noise preamplifier.
Further, R1 was 1k, and R2 was 10 k.
Furthermore, the low-noise preamplifier is cascaded with a plurality of sampling stages and has amplification factors of a plurality of measuring ranges, the amplification factor of the low-noise preamplifier is 1-100000 times, and the amplification factor of the low-noise preamplifier is selectively controlled through a switch.
Further, the signal cross-correlation analysis processing software consists of a virtual sweep frequency signal generator module, a DAQ output and acquisition module, a cross-correlation analysis module and an amplitude-frequency characteristic operation and output signal module;
The virtual sweep frequency signal generator module is formed by utilizing a corresponding functional subprogram based on a LabVIEW development platform, two paths of virtual sweep frequency sine wave signals are generated, one path of the signal is connected to the input end A of the integrated operational amplifier to be detected through the signal end of an analog output channel Vs of a data acquisition card, the voltage of the input signal of the input end of the integrated operational amplifier to be detected is changed by changing the range of a virtual signal source of the virtual sweep frequency signal generator module, the frequency of the output signal Vs is changed through the virtual sweep frequency of the virtual sweep frequency signal generator module, the other path of the virtual signal generated by the virtual sweep frequency signal generator module provides a reference virtual sweep frequency sine wave signal Vr, the reference virtual sweep frequency sine wave signal Vr and the output signals Vo1 and Vo2 of an amplifier acquired by the data acquisition card are subjected to cross-correlation operation respectively by a cross-correlation analysis, the two paths of signals have a frequency following function; the reference virtual sweep sine wave signal Vr is obtained from the inside through a virtual sweep signal generator and is directly sent to a cross-correlation operation module; sweep sine wave signal Vs output by the data acquisition card, reference virtual sweep sine wave signal Vr generated by the virtual sweep signal generator module, output sweep sine wave signal Vo1 of the integrated operational amplifier to be tested, output sweep sine wave signal Vo2 of the low-noise preamplifier containing noise, waveforms of Vo1, Vr, Vo2 and Vr which are analyzed and operated by the cross-correlation analysis module respectively, and an open-loop amplitude-frequency characteristic curve of the integrated operational amplifier are displayed in the amplitude-frequency characteristic curve and waveform data processing and displaying module.
Further, the amplitude of the reference virtual sweep sine wave signal Vr is 1, and the real-time frequency is the same as the input signal of the data acquisition card.
The invention has the advantages of improving the measurement precision of the amplitude-frequency characteristic of the integrated operational amplifier open loop, realizing automatic test, along with simple structure, high precision, wide test range and visual reading of the test device.
drawings
FIG. 1 is a schematic diagram of the system of the present invention.
In the figure, 1, an integrated operational amplifier to be tested, 2, a low-noise preamplifier, 3, a data acquisition card, 4, a direct-current power supply and 5, a computer are arranged.
Detailed Description
The present invention will be described in detail with reference to the following embodiments.
The invention relates to a system and a method for measuring alternating current open loop amplitude-frequency characteristics of an integrated operational amplifier when the integrated operational amplifier works in a closed loop state. As shown in fig. 1, the negative input end a of the integrated operational amplifier 1 to be tested, one end of the resistor R1, one end of the resistor R2, and the negative input end C of the low-noise preamplifier 2 are connected together, the other end of the resistor R1 is connected to the channel 0 of the data acquisition card 3, the other end of the resistor R2, the amplified output signal Vo1 of the integrated operational amplifier 1 to be tested, and the channel 1 of the data acquisition card 3 are connected together, the positive input end B of the integrated operational amplifier 1 to be tested is grounded, the positive input end D of the low-noise preamplifier 2 is grounded, the output end Vo2 of the low-noise preamplifier 2 is connected to the channel 2 of the data acquisition card 3, the data acquisition card 3 is connected to the computer 5, the data acquired by the data acquisition card 3 is provided to the computer 5, and the open-loop amplitude-frequency characteristic curve of the integrated operational amplifier to be. The amplified output signal Vo1 of the integrated operational amplifier 1 to be tested and the amplified output signal Vo2 of the low noise preamplifier 2 are respectively connected to the analog input terminal of the data acquisition card 3. The integrated operational amplifier 1 to be tested forms a negative feedback amplifier, the gain of the integrated operational amplifier 1 to be tested is determined by an input resistor R1 and a feedback resistor R2, wherein R1 is 1k, and R2 is 10 k. The signals Vo1 and Vo2 are collected and transmitted to the computer 5 by the data acquisition card 3. The data acquisition card 3 is inserted into the computer 5. And outputting a sweep sine wave signal Vs generated by the virtual sweep signal generator by the data acquisition card and sending the sweep sine wave signal Vs to the input of the integrated operational amplifier 1 to be tested. The amplified output signal Vo1 of the integrated operational amplifier 1 to be tested and the amplified output signal Vo2 of the low-noise preamplifier 2 are respectively connected to the analog input terminal of the data acquisition card 3. Signals Vo1 and Vo2 are collected by the data acquisition card 3 and transmitted to the computer 5, and are subjected to cross-correlation operation processing with a reference virtual sweep sine wave signal Vr generated by the virtual sweep signal generator by labVIEW software, so that values of Vo1 and Vo2 are obtained, and a value of Vi is obtained.
The virtual sweep frequency signal generator module is realized by LabVIEW software in the computer 5, two sweep frequency virtual sine wave signals are generated, one signal is connected to the input end A of the integrated operational amplifier 1 to be tested through the analog output channel Vs signal end of the data acquisition card 3, the input signal voltage of the input end of the integrated operational amplifier is changed by changing the measuring range of a virtual signal source, and the frequency of the output signal Vs is changed through virtual sweep frequency. And the other path of virtual signal generated by the sweep frequency virtual sine wave signal provides a reference virtual sweep frequency sine wave signal Vr, and the reference virtual sweep frequency sine wave signal Vr and output signals Vo1 and Vo2 of the amplifier acquired by the acquisition card respectively perform cross correlation and other operations. The frequency of the Vr signal is the same as the frequency of an input signal Vs of the integrated operational amplifier 1 to be tested, and the amplitude of the Vr signal is 1V. In order to ensure that the frequencies of the two voltage signals are the same, the two voltage signals have a frequency following function.
The low-noise preamplifier 2 is cascaded with a plurality of sampling multistage amplifiers, has the amplification factor of a plurality of measuring ranges, and can be selectively controlled through a switch, wherein the amplification factor is 1-100000 times. The low-noise preamplifier 2 is used for amplifying a weak input voltage signal Vi of the integrated operational amplifier to be detected, which is accompanied by noise, to a level which is enough to push the acquisition card to work.
The collected signals and the amplitude-frequency characteristic curve are displayed in a waveform mode, paging display is adopted in a front panel, switching is carried out between interfaces, and the following steps are carried out from left to right: the sweep sine wave signal Vs output by the data acquisition card 3, the reference virtual sweep sine wave signal Vr generated by the virtual sweep signal generator module, the output sweep sine wave signal Vo1 of the integrated operational amplifier 1 to be tested, and the output sweep sine wave signal Vo2 of the low-noise preamplifier 2 containing noise. The waveforms of Vo1, Vr, Vo2 and Vr after analysis and operation by the cross-correlation analysis module and the open-loop amplitude-frequency characteristic curve of the integrated operational amplifier are displayed in the amplitude-frequency characteristic curve and waveform data processing and displaying module.
The output of the integrated operational amplifier 1 to be tested and the low-noise preamplifier 2 is visually seen through a numerical value display control. The results of the measurements included 4 quantities: namely, the voltage value of the output Vo1 of the integrated operational amplifier 1 to be tested, the voltage value of the output Vo2 of the low-noise preamplifier 2, the open-loop Gain value of the integrated operational amplifier 1 to be tested, and the real-time frequency value of the sweep frequency signal. A program diagram realized by Labview software comprises a virtual sweep frequency signal generator, DAQ output and acquisition, cross-correlation analysis, amplitude-frequency characteristic operation and signal output. The sampling information comprises a sampling rate (Fs) per second and the sampling number of the waveform sampled each time, and the sampling information of the virtual sweep frequency signal generator is consistent with the sampling information of the output signal Vs of the data acquisition card and the tested signals Vo1 and Vo 2. The virtual sweep frequency signal generator is composed of a basic signal generator and a while circulating and shifting register in a signal processing-waveform generating template, and generates 2 paths of signals, wherein one path is a reference virtual sweep frequency sine wave signal Vr, and the other path is a signal to be detected and is sent to a data acquisition card in a computer. The output signal Vs and the input signals (signals to be measured Vo1, Vo2) are output and obtained from the data acquisition card by the DAQ assistant in the Signalexpress board, and the 'amplification factor' adjusting knob is used for adjusting the amplification factor of the input signal of the preamplifier, and the amplification factor corresponds to the amplification factor of the preamplifier in the hardware circuit.
The reference virtual sweep sine wave signal Vr is obtained from the inside through a virtual sweep signal generator and is directly sent to a cross-correlation operation module. The amplitude of the reference virtual sweep sine wave signal Vr is 1, the reference virtual sweep sine wave signal Vr is a standard reference signal, and the real-time frequency is still the same as the input signal of the data acquisition card.
The function of cross-correlation analysis of the measurement signals Vo1, Vo2 and the reference virtual swept sine wave signal Vr is provided by a time domain analysis template in LabVIEW. And the cross correlation VI is positioned in Functions > analysis > Signal Processing > Time Domain >, and a cross correlation function is called to calculate the cross correlation function of the discrete sequence.
The Cross-correlation algorithm is realized by calling the Functions > Signal Processing > Time Domain > Cross correlation.vi sub-template in LabVIEW.
In the cross-correlation analysis block diagram program of the measurement signals Vo1 and Vo2 and the reference virtual swept sine wave signal Vr, because the signal analysis requires to be performed circularly and the whole process is expected to be man-machine interactive, a While circular structure is adopted in the program design of the rear panel.
The cross-correlation function of the two periodic signals of the measurement signal and the reference signal is still the periodic signal with the same frequency, and the amplitude information of the original measurement signal is kept.
Through the operation of the cross-correlation function, the output voltage Vo1 of the integrated operational amplifier to be tested and the output voltage Vo2 of the preamplifier are output through the numerical display control. Because the preamplifier amplifies the input of the integrated operational amplifier to be tested in the hardware circuit, a 'magnification' knob is added in the software to calculate the voltage of the input end of the integrated operational amplifier to be tested. Gain is calculated through function operation such as 'Logiathm Base 10'. The "Logarithm Base 10" function is located in the Express > arithmetic and compare > math > exponential function palette. After the program runs, the signal generated by the virtual sweep frequency signal generator is a sweep frequency signal, the calculated voltage Gain value Gain under each frequency point and the frequency value of each frequency point of the corresponding sweep frequency signal are sent to create an XY diagram, an amplitude-frequency characteristic curve is automatically drawn, and the processed and calculated data are displayed through a display part.
The system comprises a virtual sweep frequency signal generator module, a DAQ output and acquisition module, a cross-correlation analysis module, an amplitude-frequency characteristic operation and output signal module and the like, which are all researched and developed based on a LabVIEW development platform and an accessory software package thereof.
The system has the functions of a virtual sweep frequency signal generator, DAQ output and acquisition, cross-correlation analysis, amplitude-frequency characteristic operation, signal output and the like, and is formed by utilizing corresponding functional subprograms (VI) based on a LabVIEW development platform.
The invention utilizes virtual instrument technology to complete the generation of sweep frequency signals, cross-correlation detection, amplitude-frequency characteristic measurement and other parts on a PC, adopts LabVIEW software programming to realize the cross-correlation analysis of an output signal Vo1 of an integrated operational amplifier to be tested, an output signal Vo2 of a low-noise preamplifier and a reference virtual sweep frequency sine wave signal Vr generated by a virtual sweep frequency signal generator module 53, amplitude-frequency characteristic operation and real-time display and monitoring of waveform data, and achieves the aim of testing the amplitude-frequency characteristic of an open loop of the integrated operational amplifier. The method fully utilizes the advantages of strong noise suppression and useful signal recovery and extraction capability, high measurement accuracy and resolution and the like of a correlation analysis method. The invention relates to an integrated operational amplifier open-loop amplitude-frequency characteristic test system, which adopts the relevant measurement with good specificity, communication and portability, fully utilizes the powerful function of a computer, and has the characteristics of flexible and convenient software programming, simplicity, high efficiency and stable performance due to the characteristics of the development function and flexibility of a graphical user interface, thereby realizing the automatic processing and judgment of data, having visual display and high efficiency.
The invention also has the advantages that: the invention realizes the measurement of the open-loop amplitude-frequency characteristic of the integrated operational amplifier under the closed-loop working condition, eliminates the influence of factors such as unstable working state, offset voltage, offset current and drift of the integrated operational amplifier during the open-loop working, and solves the problem that the open-loop amplitude-frequency characteristic of the integrated operational amplifier cannot be measured during the open-loop working of the integrated operational amplifier; the measurement precision of the amplitude-frequency characteristic of the integrated operational amplifier open loop is further improved; the test is automatic, and the cost of the test system is greatly reduced; the testing device has the advantages of simple structure, high precision, wide testing range, simple and convenient measuring operation and visual reading; can be widely used in factories, research institutes and laboratories.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not intended to limit the present invention in any way, and all simple modifications, equivalent variations and modifications made to the above embodiments according to the technical spirit of the present invention are within the scope of the present invention.
Claims (6)
1. The utility model provides an integrated operational amplifier open loop amplitude-frequency characteristic test system which characterized in that: the method comprises the steps that a negative input end A of the integrated operational amplifier to be tested, one end of a resistor R1, one end of a resistor R2 and a negative input end C of a low-noise preamplifier are connected together, the other end of a resistor R1 is connected with a channel 0 of a data acquisition card, the other end of a resistor R2, an amplified output signal Vo1 of the integrated operational amplifier to be tested and a channel 1 of the data acquisition card are connected together, a positive input end B of the integrated operational amplifier to be tested is grounded, a positive input end D of the low-noise preamplifier is grounded, an output end Vo2 of the low-noise preamplifier is connected with a channel 2 of the data acquisition card, the data acquisition card is connected with a computer, data acquired by the data acquisition card is provided for the computer, and signal analysis processing software in the computer analyzes the data card to obtain an open-loop amplitude-frequency.
2. The integrated operational amplifier open loop amplitude-frequency characteristic testing system according to claim 1, characterized in that: the positive input end B of the integrated operational amplifier to be tested is connected with the ground end of the direct current power supply, the positive input end D of the low-noise preamplifier is connected with the ground end of the direct current power supply, and the direct current power supply is connected with the integrated operational amplifier to be tested and the low-noise preamplifier.
3. The integrated operational amplifier open loop amplitude-frequency characteristic testing system according to claim 1, characterized in that: the R1 is 1k, and the R2 is 10 k.
4. The integrated operational amplifier open loop amplitude-frequency characteristic testing system according to claim 1, characterized in that: the low-noise preamplifier is cascaded with a plurality of measuring ranges and has the amplification factor of 1-100000 times, and the amplification factor of the low-noise preamplifier is selectively controlled through a switch.
5. The integrated operational amplifier open loop amplitude-frequency characteristic testing system according to claim 1, characterized in that: the signal cross-correlation analysis processing software consists of a virtual sweep frequency signal generator module, a DAQ output and acquisition module, a cross-correlation analysis module and an amplitude-frequency characteristic operation and output signal module;
The virtual sweep frequency signal generator module is formed by utilizing a corresponding functional subprogram based on a LabVIEW development platform, two paths of virtual sweep frequency sine wave signals are generated, one path of the signal is connected to the input end A of the integrated operational amplifier to be detected through the signal end of an analog output channel Vs of a data acquisition card, the voltage of the input signal of the input end of the integrated operational amplifier to be detected is changed by changing the range of a virtual signal source of the virtual sweep frequency signal generator module, the frequency of the output signal Vs is changed through the virtual sweep frequency of the virtual sweep frequency signal generator module, the other path of the virtual signal generated by the virtual sweep frequency signal generator module provides a reference virtual sweep frequency sine wave signal Vr, the reference virtual sweep frequency sine wave signal Vr and the output signals Vo1 and Vo2 of an amplifier acquired by the data acquisition card are subjected to cross-correlation operation respectively by a cross-correlation analysis, the two paths of signals have a frequency following function; the reference virtual sweep sine wave signal Vr is obtained from the inside through a virtual sweep signal generator and is directly sent to a cross-correlation operation module; sweep sine wave signal Vs output by the data acquisition card, reference virtual sweep sine wave signal Vr generated by the virtual sweep signal generator module, output sweep sine wave signal Vo1 of the integrated operational amplifier to be tested, output sweep sine wave signal Vo2 of the low-noise preamplifier containing noise, waveforms of Vo1, Vr, Vo2 and Vr which are analyzed and operated by the cross-correlation analysis module respectively, and an open-loop amplitude-frequency characteristic curve of the integrated operational amplifier are displayed in the amplitude-frequency characteristic curve and waveform data processing and displaying module.
6. the integrated operational amplifier open loop amplitude-frequency characteristic testing system according to claim 5, wherein: the amplitude of the reference virtual sweep sine wave signal Vr is 1, and the real-time frequency of the reference virtual sweep sine wave signal Vr is the same as the input signal of the data acquisition card.
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| CN1099597C (en) * | 1998-03-03 | 2003-01-22 | 韩熔 | On-line detection method for function of operational amplifier |
| TWI361900B (en) * | 2007-12-27 | 2012-04-11 | Univ Nat Chiao Tung | Device for accurately measuring amplifier's open-loop gain with digital stimuli |
| EP2279423B1 (en) * | 2008-04-21 | 2018-08-08 | Anteverta-MW B.V. | Open loop load pull arrangement with determination of injections signals |
| US9246650B2 (en) * | 2008-06-04 | 2016-01-26 | Nokia Solutions And Networks Oy | Method, apparatus and computer program for open loop transmission diversity |
| CN101997490B (en) * | 2009-08-26 | 2013-08-21 | 复旦大学 | Constant gain time amplifier adopting digital calibration technology |
| US9654120B2 (en) * | 2012-07-26 | 2017-05-16 | Qualcomm Incorporated | System and method of determining an oscillator gain |
| CN103226326A (en) * | 2013-03-11 | 2013-07-31 | 上海电力学院 | Frequency domain analysis method for ship autopilot system |
| CN103823168B (en) * | 2014-03-10 | 2016-06-22 | 中国科学院电子学研究所 | Testing circuit and device to gas-insulated gas insulated metal enclosed swit chgear shelf depreciation |
| CN104092442B (en) * | 2014-06-04 | 2017-02-22 | 广东顺德中山大学卡内基梅隆大学国际联合研究院 | Lock-in amplifier of analog-digital mixed structure and lock-in amplification method of lock-in amplifier |
| CN104065373B (en) * | 2014-06-24 | 2017-03-15 | 北京控制工程研究所 | A kind of linear work power MOSFET tube parallel method |
| CN104460655B (en) * | 2014-11-07 | 2017-07-28 | 南京英纳瑞电气有限公司 | The frequency response detection of Excitation Controller and parameter Optimization Analysis method and system |
| CN104615126B (en) * | 2015-01-28 | 2017-08-08 | 苏州汇川技术有限公司 | A kind of frequency response characteristic test system and method based on control system |
| CN204422662U (en) * | 2015-02-26 | 2015-06-24 | 北京芯动联科微电子技术有限公司 | A kind ofly adopt the multiplexing capacitive detection circuit of the time division multiplexed of Open-loop amplifier |
| CN104913930A (en) * | 2015-05-17 | 2015-09-16 | 成都诚邦动力测试仪器有限公司 | High-open-loop gain operational amplification-based gearbox testing system |
| CN105471520B (en) * | 2015-11-11 | 2018-10-12 | 中国电子科技集团公司第四十一研究所 | A kind of automatic adjustment method of the open loop power linearity applied to signal generator |
| CN106684866A (en) * | 2017-01-09 | 2017-05-17 | 南方电网科学研究院有限责任公司 | Calculation method and apparatus for static state open loop comprehensive gain |
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