Design of DAC 1ppm Analog-to-Digital Conversion Precision Instrument

Seiko original 32.768KHZ 3215 (3.2*1.5mm) 12.5P

L0504-Murata muRata common mode inductor 90Î© 150mA

Overview:
In order to improve the accuracy of the instrumentation system, the performance of the digital-to-analog converter has exceeded 16 bits, and it has been necessary to use a cumbersome, expensive, slow-speed Kelvin-Varley voltage divider to achieve this level of performance.

However, as time goes by, markets and technologies continue to evolve, and the definition of precision digital-to-analog converters has changed. The development of semiconductor processing technology, DAC design and calibration technology has made it possible to have high linearity digital-to-analog converters. This converter not only has good stability, short settling time, but also provides 20-bit performance better than 1ppm. These small ICs guarantee performance specifications that require no calibration and are easy to use.

The range of applications for 1ppm DACs ranges from gradient coil control in medical MRI systems to precision sources and positioning in mass spectrometry, test and measurement applications.

$</p><p>Performance Indicator</p><p >The circuit shown in Figure 1 provides 1ppm performance. The key technical indicators are integral nonlinearity, differential nonlinearity and 0.1Hz to 10Hz. Peak-to-peak noise. </p><p> In Figure 1, U1 is a 20-bit DAC with a 1ppm linearity specification. U2 is a precision dual-channel amplifier that acts as a drive-detect buffer for the DAC reference input. U3 is a precision output buffer that is used to drive the load. Its key requirements are similar to the reference buffer, which includes low noise, low offset voltage, low drift, and low input bias current. </p><p>Although less than 1ppm of precision components are available, building a 1ppm system is not an easy task and should not be taken lightly. The main sources of error in 1ppm precision circuits are noise, temperature drift, and thermoelectric voltage. (Please read the PDF for details)</p> </div> </div> <div class="tech-detail-share">  <div class= "bdsharebuttonbox"> <a href="#" class="bds_qzone" data-cmd="qzone" title="Share to QQ Space"></a> <a href="#" class="bds_tsina" data- Cmd="tsina" title="Share to Sina Weibo"></a> <a href="#" class="bds_weixin" data-cmd="weixin" title="Share to WeChat"></a> <span>Share to:</span> </div> <script>window._bd_share_config = { "common": { "bdSnsKey": {}, "bdText": "", "bdMini": "1", " bdMiniList": false, "bdPic": "", "bdStyle": "2", "bdSize": "16" }, "share": {} }; with (document) 0[(getElementsByTagName($

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