Summary of the invention
The problem that the present invention solves provides a kind of testing apparatus and corresponding method of testing, can utilize memorizer test device that A/D converter, D/A converter are tested.
For addressing the above problem, the embodiment of the invention provides a kind of testing apparatus, comprising:
Signal input apparatus, memorizer test device, D/A converter, A/D converter, test cell; Said memorizer test device comprises first memory unit and second memory unit; One of them is standard converter for said D/A converter, A/D converter, and another is a transducer to be tested;
Said signal input apparatus is used to produce digital vectors, and said digital vectors is stored in the first memory unit in the memorizer test device;
Said memorizer test device converts the digital vectors in the said first memory unit into analog signal through D/A converter, and said analog signal is sent to A/D converter;
Said A/D converter becomes digital signal with said analog signal conversion, and is stored in the second memory unit of said memorizer test device;
Said test cell is handled the performance parameter that tests out transducer to be tested to the digital signal in the second memory unit; The performance parameter of said transducer to be tested and the measurement parameter of standard are compared, judge whether transducer to be tested meets specification requirement.
Optional, when said D/A converter is a standard converter, said A/D converter is a transducer to be tested, and the precision of said D/A converter is higher than the precision of said A/D converter.
Optional, when said A/D converter is a standard converter, said D/A converter is a transducer to be tested, and the precision of said A/D converter is higher than the precision of said D/A converter.
Optional, also comprise: the low pass filter between said D/A converter, A/D converter, carry out filtering with the analog signal after the said D/A converter conversion.
Optional, also comprise: the operational amplification circuit between said D/A converter, A/D converter, the gain that improves D/A converter.
Optional, said signal input apparatus is an Arbitrary Waveform Generator, said Arbitrary Waveform Generator comprises signal graph generation module and Direct Digital frequency synthesis module.
Optional, said signal input apparatus also comprises the signal format modular converter, and the format conversion of the digital signal that is used for Direct Digital frequency synthesis module is produced becomes the inner data format of memorizer test device.
Optional, said memorizer test device is this memorizer test device of Caro.
Optional, said performance parameter comprises static properties parameter and dynamic performance parameter, when said static properties parameter and dynamic performance parameter satisfy specification requirement, shows that said transducer to be tested meets specification requirement; When said static properties parameter or dynamic performance parameter do not satisfy specification requirement, show that said transducer to be tested does not meet specification requirement.
Optional, said dynamic performance parameter comprises signal-noise ratio, signal-noise adds distortion, total harmonic distortion, and SFDR.
Optional; When transducer to be tested is 12; Signal-the noise ratio of said transducer to be tested; Signal-noise adds the measurement parameter scope of standard of distortion ratio for greater than 60dB, and the measurement parameter scope of the standard of said total harmonic distortion is that the measurement parameter scope of the standard of said SFDR is more than or equal to 55dB smaller or equal to-70dB.
Optional, said static properties parameter comprises integral non-linear error, differential nonlinearity error, offset error, gain error.
Optional; When transducer to be detected is 12; The measurement parameter scope of the standard of the integral non-linear error of said transducer to be tested, differential nonlinearity error is smaller or equal to 1LSB, and the measurement parameter scope of the standard of said gain error, offset error is smaller or equal to 2mV.
Technical scheme of the present invention also provides a kind of method of testing that adopts said testing apparatus, comprising:
Utilize signal input apparatus to produce digital vectors, and said digital vectors is stored in the first memory unit in the memorizer test device;
Convert the digital vectors in the said first memory unit into analog signal through said D/A converter, and said analog signal is sent to A/D converter;
Utilize said A/D converter that said analog signal conversion is become digital signal, and be stored in the second memory unit of said memorizer test device;
Utilize said test cell the digital information in the second memory unit to be handled the performance parameter that tests out device transducer to be tested; The performance parameter of said transducer to be tested and the measurement parameter of standard are compared, judge whether transducer to be tested meets specification requirement.
Optional, said performance parameter comprises static properties parameter and dynamic performance parameter, when said static properties parameter and dynamic performance parameter satisfy specification requirement, shows that said transducer to be tested meets specification requirement; When said static properties parameter or dynamic performance parameter do not satisfy specification requirement, show that said transducer to be tested does not meet specification requirement.
Optional, said dynamic performance parameter comprises signal-noise ratio, signal-noise adds distortion, total harmonic distortion, and SFDR.
Optional; When transducer to be tested is 12; Signal-the noise ratio of said transducer to be tested; Signal-noise adds the measurement parameter scope of standard of distortion ratio for greater than 60dB, and the measurement parameter scope of the standard of said total harmonic distortion is that the measurement parameter scope of the standard of said SFDR is more than or equal to 55dB smaller or equal to-70dB.
Optional, said static properties parameter comprises integral non-linear error, differential nonlinearity error, offset error, gain error.
Optional; When transducer to be detected is 12; The measurement parameter scope of the standard of the integral non-linear error of said transducer to be tested, differential nonlinearity error is smaller or equal to 1LSB, and the measurement parameter scope of the standard of said gain error, offset error is smaller or equal to 2mV.
Compared with prior art, the present invention has the following advantages:
The testing apparatus of the embodiment of the invention utilizes memorizer test device to come A/D converter, D/A converter are tested; Said testing apparatus comprises: signal input apparatus, memorizer test device, D/A converter, A/D converter, test cell; Said memorizer test device comprises first memory unit and second memory unit; One of them is standard converter for said D/A converter, A/D converter, and another is a transducer to be tested, and the digital vectors that signal input apparatus produces is stored in the first memory unit; After D/A converter, twice conversion of A/D converter; Form digital signal, and be stored in the second memory unit, utilize said test cell that said digital signal is tested then; The performance parameter of transducer to be tested and the measurement parameter of standard are compared, thereby can judge whether transducer to be tested meets specification requirement.Said testing apparatus utilizes memorizer test device to come A/D converter, D/A converter are tested, and expanded the scope of application of memorizer test device, and method of testing is simple.
Further, also there are low pass filter and operational amplification circuit between said D/A converter, the A/D converter, can reduce the noise of test signal in conversion and transmittance process, and the gain that improves D/A converter.
Embodiment
The embodiment of the invention provides a kind of testing apparatus and method of testing of utilizing memorizer test device that A/D converter, D/A converter are tested; Said testing apparatus comprises: signal input apparatus, memorizer test device, D/A converter, A/D converter, test cell; Said memorizer test device comprises first memory unit and second memory unit; One of them is standard converter for said D/A converter, A/D converter, and another is a transducer to be tested; Said signal input apparatus is used to produce digital vectors, and said digital vectors is stored in the first memory unit in the memorizer test device; Said memorizer test device converts the digital vectors in the said first memory unit into analog signal through said D/A converter, and said analog signal is sent to A/D converter; Said A/D converter becomes digital signal with said analog signal conversion, and is stored in the second memory unit of said memorizer test device; Said test cell is handled the performance parameter that tests out transducer to be tested to the digital signal in the second memory unit; The performance parameter of said transducer to be tested and the measurement parameter of standard are compared, judge whether transducer to be tested meets specification requirement.
Because one of them is standard converter for said A/D converter, D/A converter; Another is a transducer to be tested; The digital vectors that signal input apparatus is produced forms digital signal after through D/A converter, A/D converter; Utilize said test cell that the digital signal in the second memory unit is tested then,, show that said transducer to be tested satisfies specification requirement when said digital signal satisfies specification requirement.And said testing apparatus utilizes memorizer test device that A/D converter, D/A converter are tested, and expanded the scope of application of memorizer test device, and method of testing is simple.
For make above-mentioned purpose of the present invention, feature and advantage can be more obviously understandable, does detailed explanation below in conjunction with the accompanying drawing specific embodiments of the invention.
Set forth detail in the following description so that make much of the present invention.But the present invention can be different from alternate manner described here and implements with multiple, and those skilled in the art can do similar popularization under the situation of intension of the present invention.Therefore the present invention does not receive the restriction of following disclosed practical implementation.
Please refer to Fig. 1, the structural representation for the testing apparatus of the embodiment of the invention specifically comprises:
Signal input apparatus 110, memorizer test device 120, D/A converter 130, A/D converter 140; Low pass filter 150; Said memorizer test device 120 comprises first memory unit 121, second memory unit 122 and test cell 123; One of them is standard converter for said A/D converter 140, D/A converter 130, and another is a transducer to be tested;
Said signal input apparatus 110 is used to produce digital vectors, and said digital vectors is stored in the first memory unit 121 in the memorizer test device 120;
Said memorizer test device 120 converts the digital vectors in the said first memory unit 121 into analog signal through D/A converter 130, and said analog signal is sent to low pass filter 150;
After 150 pairs of said analog signals of said low pass filter are carried out filtering, send to A/D converter 140;
Said A/D converter 140 becomes digital signal with said analog signal conversion, and is stored in the second memory unit 122 of said memorizer test device 120;
Digital signal in 123 pairs of second memory unit 122 of said test cell is handled the performance parameter that tests out transducer to be tested; The performance parameter of said transducer to be tested and the measurement parameter of standard are compared, judge whether transducer to be tested meets specification requirement.
Concrete, said memorizer test device 120 comprises first memory unit 121, second memory unit 122, testing circuit board (not shown), control unit (not shown), test signal generation device (not shown).Said test signal generation device is used for producing the test signal of testing memory; The test signal of said testing memory is one group of discrete binary signal " 0 " or " 1 "; Need during testing memory earlier test signal to be input in the memory; Read test signal from memory then, and the test signal of test signal that reads and input is compared, thereby judge whether said memory is qualified.Said first memory unit 121 is used for storing said test signal and the digital channel through memorizer test device sends to testing circuit board with said test signal; In other embodiments; In the time of after said memorizer test device is testing memory, also need writing certain prestored information to the memory that satisfies specification requirement, said first memory unit further is used for preserving said prestored information.Said testing circuit board has some test probes or test socket; When memory chip is placed on the said testing circuit board; Utilize said test probe or test socket that the test signal in the first memory unit is applied on the memory to be tested, and test result is sent to the second memory unit.Said second memory unit 122 is used for the correction result of store test results and memory to be detected.Said control unit utilizes the above-mentioned relevant hardware of memory test software instruction to accomplish test.
When utilizing said memorizer test device testing memory, utilize control unit to control said test signal generation device and produce and be used for the test signal of testing memory, and said test signal is stored in the said first memory unit; Said first memory unit sends to the memory to be detected on the testing circuit board with said test signal, and through sending test result to the second memory unit behind the test circuit board test.
In embodiments of the present invention; This (Kalos) memorizer test device of the Caro that said memorizer test device 120 is a company of Credence (Credence); Said first memory unit, second memory unit are SRAM; Said first memory unit can be used for storing said test signal and said prestored information, and said second memory unit can be used for the correction result of store test results and memory to be detected.The form of the test vector of this (Kalos) memorizer test device of said Caro is 16 systems.
Because being used to test the test signal of A/D converter, D/A converter in the embodiment of the invention is continuous signal; Like sine wave signal or triangular signal; Test signal generation device in the said memorizer test device 120 can not produce above-mentioned continuous signal; Therefore, the embodiment of the invention also need increase a signal input apparatus 110 to adopting memorizer test device that A/D converter, D/A converter are tested.
In embodiments of the present invention; Said signal input apparatus 110 is an Arbitrary Waveform Generator; Said Arbitrary Waveform Generator comprises signal graph generation module and Direct Digital frequency synthesis module; Can produce test waveform arbitrarily, make the input range of test voltage inswept A/D converter, D/A converter from the zero graduation to the full scale of test waveform, thus the performance that can more comprehensively test A/D converter, D/A converter.Said signal graph generation module is a mapping software; MATLAB for example; Can draw corresponding signal graph through the editing graph function; Utilizing said graph function to obtain the graph of a correspondence data then, also can be to utilize special software the signal graph of manual drawing is sampled and to handle, and generates graph data.
Said Direct Digital frequency synthesis (DDS) module is used for the waveform that the signal graph generation module produces is directly synthesized digital vectors.Said Direct Digital frequency synthesis (DDS) module comprises FREQUENCY CONTROL register and phase accumulator; Said FREQUENCY CONTROL register can serial or parallel mode load and deposit the FREQUENCY CONTROL sign indicating number in the graph data; Said phase accumulator carries out phase-accumulated according to the FREQUENCY CONTROL sign indicating number in each clock cycle; Read the data of said graph data successively, form digital vectors.
In embodiments of the present invention; Because the test vector of this (Kalos) memorizer test device of said Caro all is 16 systems; And the digital vectors that Arbitrary Waveform Generator produces binary system normally; Said Arbitrary Waveform Generator also has the Data Format Transform unit, and the format conversion of the digital vectors that is used for Direct Digital frequency synthesis module is produced becomes the inner data format of memorizer test device.
In other embodiments, said signal input apparatus can also be common digital signal generation device, can form conventional digital waveform signal such as sine wave, ramp voltage.
The testing circuit board of said memorizer test device is used to utilize D/A converter and A/D converter to carry out digital-to-analogue conversion.Said testing circuit board has some test probes or test socket, utilizes said test probe or test socket that D/A converter and A/D converter are electrically connected with memorizer test device.In the present embodiment; Said D/A converter 130, A/D converter 140, low pass filter 150 connect mutually through test socket and are connected with memorizer test device 120 electricity; Wherein, The input of said D/A converter 130 is connected with first memory unit 121 electricity of memorizer test device 120; The output of said D/A converter 130 is connected with the input electricity of low pass filter 150, and the output of said low pass filter 150 is connected with the input electricity of A/D converter 140, and the output of said A/D converter 140 is connected with second memory unit 122 electricity of memorizer test device 120.In embodiments of the present invention, be connected with low pass filter 150 between said D/A converter 130, the A/D converter 140, be used for reducing the noise of test signal at conversion and transmittance process.In other embodiments; Be connected with low pass filter, operational amplification circuit etc. between said D/A converter, the A/D converter; Thereby can better reduce the noise of test signal in conversion and transmittance process; And said operational amplification circuit can also improve the gain of D/A converter, and is corresponding, can improve the accuracy of the test result of A/D converter.
One of them is standard converter for said D/A converter and A/D converter; Another is a transducer to be tested; Said standard converter is for satisfying the D/A or the A/D converter of specification requirement through test, the precision of said standard converter is higher than the precision of said transducer to be tested.Wherein, the precision of said n position A/D or D/A converter is V
Ref/ (2
∧N-1), said V
RefBe reference voltage.In embodiments of the present invention; Said D/A converter is a standard converter; A/D converter is a transducer to be tested; And the precision of said D/A converter is higher than the precision of said A/D converter, makes with the test result of digital signal and the deviation between the standard testing result it mainly is that performance by A/D converter determines.Through detecting the technical parameter of said digital signal, just can obtain corresponding A/D converter and whether meet specification requirement.
In embodiments of the present invention; Said test cell 123 is the test cell in the memorizer test device; Write the program of testing D/A converter, A/D converter through the control unit to said memorizer test device, said memorizer test device utilizes the static properties parameter and the dynamic performance parameter of 123 pairs of D/A converters of said program command test cell or A/D converter to test.In other embodiments; When said test cell is when being independent of the computer of memorizer test device; The digital signal of said second memory unit is sent in the computer; Utilize the trace routine of computer, for example MATLAB carries out the test of static properties parameter and dynamic performance parameter to said digital signal.And because said test cell is that digital signal is tested, digital signal is more accurate than analog signal aspect analysis and calculating, has guaranteed the accuracy of test cell.
The performance parameter of said test cell test comprises static properties parameter and dynamic performance parameter.Said static characteristic parameter comprises: integral non-linear error (INL), differential nonlinearity error (DNL), offset error, gain error etc.; Said dynamic characteristic parameter is signal-noise ratio (SNR), and signal-noise adds distortion than (SINAD), total harmonic distortion (THD), and SFDR (SFDR) etc.The performance parameter of said transducer to be tested and the measurement parameter of standard are compared,, show that said transducer to be tested meets specification requirement when the static properties parameter and the dynamic performance parameter of transducer to be tested satisfies specification requirement; When the static properties parameter or the dynamic performance parameter of transducer to be tested do not satisfy specification requirement, show that said transducer to be tested does not meet specification requirement.
The embodiment of the invention also provides a kind of method of testing that adopts said testing apparatus, utilizes D/A converter as standard converter, and A/D converter is tested.Please refer to Fig. 2, the schematic flow sheet for the method for testing of the embodiment of the invention comprises:
Step S101 utilizes signal input apparatus to produce digital vectors, and said digital vectors is stored in the first memory unit in the memorizer test device;
Step S102 converts the digital vectors in the said first memory unit into analog signal through said D/A converter, and said analog signal is sent to A/D converter;
Step S103 utilizes said A/D converter that said analog signal conversion is become digital signal, and is stored in the second memory unit of said memorizer test device;
Step S104; Utilize said test cell the digital signal in the second memory unit to be handled the performance parameter that tests out transducer to be tested; The performance parameter of said transducer to be tested and the measurement parameter of standard are compared, judge whether transducer to be tested meets specification requirement.
Concrete; In embodiments of the present invention; When utilizing said signal input apparatus to produce test signal, utilize MATLAB software to draw out the figure of test signal through the editing graph function earlier, MATLAB software converts the graph of a correspondence function to the graph of a correspondence data.In other embodiments, when utilizing said signal input apparatus to produce test signal, utilize mapping software to draw out the figure of test signal earlier, utilize special-purpose software the signal graph of correspondence is sampled and to handle then, obtain graph data.
After forming graph data; Said signal graph generation module sends said graph data to Direct Digital frequency synthesis (DDS) module through interface; Utilize said phase accumulator and FREQUENCY CONTROL register to read said graph data successively, convert said graph data to said digital vectors.Concrete; In a system clock cycle, phase accumulator obtains new accumulated value with previous accumulated value and the addition of FREQUENCY CONTROL sign indicating number; With new accumulated value as the address; Read the corresponding voltage amplitude of graph data, form digital vectors, the digital vectors that said test signal is corresponding stores in the first memory unit in the memorizer test device.
In the present embodiment; Digital vectors in the said first memory unit is sent to D/A converter; Convert analog signal to; Utilize said low pass filter that said analog signal is carried out filtering then, the noise signal of elimination high frequency, the noise of the signal that can reduce test in conversion and transmittance process.
In other embodiments; Digital vectors in the said first memory unit is sent to D/A converter; Convert analog signal to; Utilize said low pass filter that said analog signal is carried out filtering then, the noise signal of elimination high frequency, and utilize operational amplification circuit to improve the gain of D/A converter.
Said analog signal sends said A/D converter to through after the filtering of low pass filter, utilizes said A/D converter that analog signal conversion is become digital signal, and said digital signal is stored in the second memory unit.
Because existing when utilizing said memorizer test device testing memory; After utilizing control unit that said test signal is stored in said first memory unit; Said first memory unit sends to the memory to be detected on the testing circuit board through the digital channel of memorizer test device with said test signal, and through sending test result to the second memory unit behind the test circuit board test.And the said memorizer test device that utilizes of the embodiment of the invention is tested D/A converter, A/D converter; Also to the digital vectors of the said first memory unit digital channel through memorizer test device be sent to the D/A converter on the test panel; After twice conversion of D/A converter, A/D converter on the said digital vectors process test panel, also to digital signal be sent to the second memory unit.Therefore, utilize said memorizer test device test D/A converter, A/D converter need not change the structure of said memorizer test device, expanded the scope of application of said memorizer test device.
Utilize said test cell that the digital signal in the second memory unit is tested then.In embodiments of the present invention, because transducer to be tested is an A/D converter, the static characteristic parameter of said A/D converter comprises: integral non-linear error (INL), differential nonlinearity error (DNL), gain error, offset error etc.; Said dynamic characteristic parameter is signal-noise ratio (SNR), and signal-noise adds distortion than (SINAD), total harmonic distortion (THD), and SFDR (SFDR) etc.At first produce triangular wave or ramp voltage digital vectors through signal input apparatus; Triangular wave or ramp voltage digital vectors are sent into the input of D/A converter; Output output corresponding simulation triangular wave or ramp voltage signal at D/A converter; With the analog input of said simulation triangular wave or ramp voltage signal as A/D converter; And store the digital signal after the A/D converter conversion into the second memory unit, through the signal in the second memory unit being carried out the static properties parameter that computational analysis draws A/D converter.Produce the sine wave signal digital vectors through signal input apparatus then; The sine wave signal digital vectors is sent into the input of D/A converter, export corresponding analog sine voltage signal at the output of D/A converter, of the analog input of said analog sine voltage signal as A/D converter; And store the digital signal after the A/D converter conversion into the second memory unit; The digital signal that said sine wave signal is corresponding is carried out fast Fourier transform (FFT), obtains the signal-noise ratio (SNR) of A/D converter, and signal-noise adds distortion than (SINAD); Total harmonic distortion (THD), and SFDR dynamic performance parameters such as (SFDR).Compare through the static properties parameter of A/D converter that said test cell is recorded and the measurement parameter of dynamic performance parameter and standard; When said static properties parameter and dynamic performance parameter satisfy specification requirement, show that said A/D converter meets specification requirement; When said static properties parameter or dynamic performance parameter do not satisfy specification requirement, show that said A/D converter does not meet specification requirement.
In embodiments of the present invention; A/D converter to be detected is 12; Signal-the noise ratio of said A/D converter (SNR); Signal-noise add distortion than the measurement parameter scope of the standard of (SINAD) for greater than 60dB, the measurement parameter scope of the standard of said total harmonic distortion (THD) is that the measurement parameter scope of the standard of said SFDR (SFDR) is more than or equal to 55dB smaller or equal to-70dB.The measurement parameter scope of the standard of said integral non-linear error (INL), differential nonlinearity error (DNL) is smaller or equal to 1LSB (Least Significant Bit; Least significant bit), the measurement parameter scope of the standard of said gain error, offset error is smaller or equal to 2mV.When the scope of the static properties parameter of the said A/D converter that records and the standard compliant measurement parameter of dynamic performance parameter, explain to show that said A/D converter meets specification requirement.When the scope of the static properties parameter of the said A/D converter that records or the non-compliant measurement parameter of dynamic performance parameter, show that said A/D converter does not meet specification requirement.
In other embodiments; When the A/D converter of said test only needs reference section dynamic performance parameter or static properties parameter also can reach certain conversion accuracy; Also can compare by a measurement parameter, judge whether A/D converter meets specification requirement partial dynamic performance parameter or static properties parameter and standard.
In other embodiments; When said transducer to be tested is D/A converter; Compare through the static properties parameter of D/A converter that said test cell is recorded and the measurement parameter of dynamic performance parameter and standard, can obtain said D/A converter and whether meet specification requirement.
To sum up; The testing apparatus of the embodiment of the invention utilizes memorizer test device to come A/D converter, D/A converter are tested; Said testing apparatus comprises: signal input apparatus, memorizer test device, D/A converter, A/D converter, test cell, said memorizer test device comprise first memory unit and second memory unit, and one of them is standard converter for said D/A converter, A/D converter; Another is a transducer to be tested; The digital vectors that signal input apparatus produces is stored in the first memory unit, after D/A converter, twice conversion of A/D converter, forms digital signal; And be stored in the second memory unit; Utilize said test cell that said digital signal is tested then, the performance parameter of said transducer to be tested and the measurement parameter of standard are compared, thereby can judge whether transducer to be tested meets specification requirement.Said testing apparatus utilizes memorizer test device to come A/D converter, D/A converter are tested, and expanded the scope of application of memorizer test device, and method of testing is simple.
Further, also there are low pass filter and operational amplification circuit between said D/A converter, the A/D converter, can reduce the noise of test signal in conversion and transmittance process, and the gain that improves D/A converter.
Though the present invention with preferred embodiment openly as above; But it is not to be used for limiting the present invention; Any those skilled in the art are not breaking away from the spirit and scope of the present invention; Can utilize the method and the technology contents of above-mentioned announcement that technical scheme of the present invention is made possible change and modification, therefore, every content that does not break away from technical scheme of the present invention; To any simple modification, equivalent variations and modification that above embodiment did, all belong to the protection range of technical scheme of the present invention according to technical spirit of the present invention.