【導(dǎo)讀】量，總諧波失真，總諧波失真加噪聲，信噪比等。在確定模型參數(shù)進(jìn)行的時(shí)間以及在光譜。領(lǐng)域比較所取得的結(jié)果。在軟件開(kāi)發(fā)LabWindows/CVI（C語(yǔ)言）和實(shí)行的低層次的Win32API. 作者的意圖是應(yīng)用軟件進(jìn)行計(jì)算機(jī)部件供應(yīng)商,為教育示范的ADC測(cè)試原理。文章還包括了幾個(gè)例子，取得了有趣的結(jié)果從測(cè)試一些PC聲卡和實(shí)用的作者的經(jīng)驗(yàn)，以被認(rèn)為是他們的“標(biāo)準(zhǔn)”音頻(模擬)接口。統(tǒng)，可以從化學(xué)，壓力，振動(dòng)等傳感器的信號(hào)。流或半直流信號(hào)通過(guò)應(yīng)用菜刀，或者由在PC卡輸入數(shù)字調(diào)制解調(diào)其次放大器。1241和DYNAD草稿中的實(shí)例驗(yàn)證聲卡的應(yīng)用可能性表示的大不相同過(guò)。目前，新的，即將被公認(rèn)標(biāo)準(zhǔn)IEEE性病。然而，這個(gè)標(biāo)準(zhǔn)涵蓋了靜態(tài)和準(zhǔn)靜態(tài)測(cè)試大多主要基于直方圖方法測(cè)試，其不足的。申請(qǐng)的決定，很多程序詳見(jiàn)DYNADIEEE性病的評(píng)估。該軟件被創(chuàng)造的目的是最大的綜合性在音效卡的測(cè)試。軟件開(kāi)發(fā)環(huán)境LabWindows/約定保險(xiǎn)價(jià)值的民族樂(lè)器的支持下，

　　

【正文】 prevent correct determination of other recorder parameters. Fullsize image (20K) Fig. 6. Recorded sine wave for the 16bit mode from m55. The limitation on level 16,062 totally degrades the CM8330 parameters. View Within Article Sound cards implemented in notebooks were also tested. The most interesting results were achieved at notebook Acer TravelMate 212TX [16] with audio 16bit AC39。97 stereo codec. Table 3 and Fig. 7 illustrate some of them. Table 3. Results from ENOB testing of sound CODEC implemented in notebook Acer TravelMate 212TX 本科畢業(yè)設(shè)計(jì)（論文）外文翻譯 21 Fullsize table (1K) Fullsize image (47K) Fig. 7. (a) ENOB dependence on test signal frequency for the 8 (*) and 16 ()bit mono modes of sound blaster implemented in notebook Acer TravelMate 212TX. (b) Typical spectrum for the 16bit mode of sound blaster implemented in notebook Acer TravelMate 212TX (test frequency 本科畢業(yè)設(shè)計(jì)（論文）外文翻譯 22 kHz, sampling frequency 44,100 Hz). (c) Detail of typical spectrum for the 16bit mode of sound blaster implemented in notebook Acer TravelMate 212TX (test frequency kHz, sampling frequency 44,100 Hz). View Within Article The achieved results indicate, likewise herein before, a bad quality of audio input in the tested notebook especially in the 16bit mode. Moreover, the strange spectrum shown in Fig. 7b and c implies an idea that the real sampling frequency in the sound codec is different from the set one or that the digital filter in the sigma–delta ADC does not work correctly. The last example is the ―standalone‖ plugin board Sound Blaster PCI64 by Creative Technology [15]. Some achieved results are shown in Table 4 and Fig. 8 and Fig. 9. In parison with previous sound blasters, this card proved lightly better metrological parameters. Table 4. ENOB dependence on the test signal frequency of Sound Blaster PCI64 Fullsize table (1K) View Within Article 本科畢業(yè)設(shè)計(jì)（論文）外文翻譯 23 Fullsize image (28K) Fig. 8. (a) ENOB dependence on test signal frequency for the 8 (*) and 16 ()bit mono modes of Sound Blaster PCI 64. (b) Typical spectrum in the 16bit mode of Sound Blaster PCI64 (test frequency 211 Hz, sampling frequency 44,100 Hz). View Within Article Fullsize image (41K) 本科畢業(yè)設(shè)計(jì)（論文）外文翻譯 24 Fig. 9. Distortion observed at Sound Blaster PCI64 for input signal meeting the full scale of audio input (input frequency 21 Hz, sampling frequency 44,100 Hz). View Within Article The sound card in the 8bit mode seems to be very close to the ideal one—the results of more than 8 bits are caused by the parison of the real quantisation noise with the ideal, whose normalised power is simplified, in most standards, to be 1/12. However, the maximum achieved value of ENOB in the 16bit mode was only slightly more than 12 bits, which is still far away from the declared 16bit resolution. Moreover, if the input signal meets nearly the full scale of tested audio input, a significant nonlinear distortion was observed in the recorded data (see Fig. 9). Testing the same card in different PCs brought only negligible differences in the achieved results—not more than bit and typically only about bit. This fact indicates that the main influence on the metrological parameters of sound card has the card design and not the disturbance of other PC ponents. 6. Conclusions The developed software was applied and tested in the assessment of a few sound cards. It seems to be a very useful tool—it enables measurement and acquisition of many plex parameters of sound cards in a relatively short time. Developed software employment by PC retailers can lead to the improvement of quality and confidence of offered PC ponents. The software will also be used in the educational process of teaching electronic measurement and data acquisition systems at the Technical University of Ko ice as a demonstration virtual instrument for the explanation and demonstration of standard ADC test methods. The achieved results from the executed tests of various sound cards indicate a generally low quality of their audio inputs from the metrological point of view. This fact is especially evident in the 16bit mode. The standalone plugin sound cards seem to be a bit better (by 1–2 bits) than the sound cards integrated on motherboards. Disturbing effects caused by other ponents inside PC seem to have much less influence on metrological parameters of the sound cards than the sound card design. All these facts restrict sound card application only on simple systems where the needed resolution is not higher than 10–12 bits. Moreover, there are big differences between the metrological parameters of the various sound cards. References 1. IEEE Std. 10571994, Standard for Digitizing Waveform Recorders. 2. IEEE Std. 1241, Draft ver. VS022500. 3. DYNAD, Draft ver. , 20xx. 4. P. Arpaia, F. Cennamo and P. Daponte , Metrological characterisation of analogtodigital converters—a state of the art. In: Proceedings of the Third International Conference on Advanced A/D and D/A Conversion Techniques and their Applications (Conf. Publ. no. 466) (1999), pp. 134–144. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (0) 5. M. Pokorny, J. Roztocil and V. Haasz , Suppression of test signal distortion by ADmodules. In: Dynamic Testing, Proceedings of IMEKO TC4 Symposium ISSDMI 39。98, Naples, Italy (1998), pp. 889–892. 6. M. Pokorny and V. Haasz , Alternative method of A/D conversion quality verification. In: Instrumentaion and Measurement Technology Conference, IMTC/99, Proceedings of the 16th IEEE, 本科畢業(yè)設(shè)計(jì)（論文）外文翻譯 25 Venice, Italy vol. 3 (1999), pp. 1421–1424. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (1) 7. R. Holcer , The performance test of AD