<p style="word-wrap:break-word; word-break:break-all; margin-top:0px; margin-bottom:0px; padding-top:0px; padding-bottom:0px; color:rgb(68,68,68); font-family:Tahoma,'Microsoft Yahei',Simsun; font-size:14px; line-height:28px; background-color:rgb(239,245,249)"> <span style="word-wrap:break-word; word-break:break-all; color:rgb(112,114,111)">TMS320F28335内部包含12位AD转换器，其功能有：<br style="word-wrap:break-word; word-break:break-all"> 具有内置（采样保持）S/H的12位ADC内核<br style="word-wrap:break-word; word-break:break-all"> 模拟输入：0.0V至3.0V（高于3.0V的电压产生满刻度转换结果）。<br style="word-wrap:break-word; word-break:break-all"> 快速转换率：在25MHzADC时钟12.5MSPS上时高达80ns<br style="word-wrap:break-word; word-break:break-all"> 16个专用ADC通道。<br style="word-wrap:break-word; word-break:break-all"> 每次采样/保持都有复用的8通道<br style="word-wrap:break-word; word-break:break-all"> 自动定序功能在单次会话中可提供多达16次“自动转换”。可将每次转换编程为选择16个输入信道中的任何一个。<br style="word-wrap:break-word; word-break:break-all"> 序列发生器可运行为2个独立的8态序列发生器，或作为1个较大的16态序列发生器（即2个级联的8态序列发生器）。<br style="word-wrap:break-word; word-break:break-all"> 用于存储转换值的16个结果寄存器（可分别寻址）<br style="word-wrap:break-word; word-break:break-all"> – 输入模拟电压的数值源自：<br style="word-wrap:break-word; word-break:break-all"> 当input<0时：digital value =0；<br style="word-wrap:break-word; word-break:break-all"> 当0<input<3.0时：digital value =4096*(input analog voltage-ADCLO)/3；<br style="word-wrap:break-word; word-break:break-all"> 当input>3.0时：digital value =4095；</span></p>
<p style="word-wrap:break-word; word-break:break-all; margin-top:0px; margin-bottom:0px; padding-top:0px; padding-bottom:0px; color:rgb(68,68,68); font-family:Tahoma,'Microsoft Yahei',Simsun; font-size:14px; line-height:28px; background-color:rgb(239,245,249)"> <span style="word-wrap:break-word; word-break:break-all; color:rgb(112,114,111)"><br style="word-wrap:break-word; word-break:break-all"> 作为转换开始(SOC)序列源的多个触发器<br style="word-wrap:break-word; word-break:break-all"> – S/W-软件立即启动<br style="word-wrap:break-word; word-break:break-all"> – ePWMM转换开始<br style="word-wrap:break-word; word-break:break-all"> – XINT2ADC转换开始<br style="word-wrap:break-word; word-break:break-all"> 灵活的中断控制允许每个序列结束(EOS) 或每个其它EOS上的中断请求。<br style="word-wrap:break-word; word-break:break-all"> 序列发生器可运行于“启/停”模式，从而实现多个“时序触发器”同步转换。<br style="word-wrap:break-word; word-break:break-all"> SOCA和SOCB触发器可独立运行在双序列发生器模式中。<br style="word-wrap:break-word; word-break:break-all"> 采样保持(S/H)采集时间窗口具有独立的预分频控制。</span></p>
<p style="word-wrap:break-word; word-break:break-all; margin-top:0px; margin-bottom:0px; padding-top:0px; padding-bottom:0px; color:rgb(68,68,68); font-family:Tahoma,'Microsoft Yahei',Simsun; font-size:14px; line-height:28px; background-color:rgb(239,245,249)"> <span style="word-wrap:break-word; word-break:break-all; color:rgb(112,114,111)">要获得指定的ADC精度，正确的电路板布局非常关键。为尽可能达到最佳效果，引入ADCIN引脚的走线不应太靠近数字信号通道。这是为了最大程度地减少数字线路上因ADC输入耦合而产生的开关噪声。而且，适当的隔离技术必须被用来将数字电源从ADC模块电源引脚(VDD1A18，VDD2A18，VDDA2，VDDAIO)上隔离。</span></p>
<p style="word-wrap:break-word; word-break:break-all; margin-top:0px; margin-bottom:0px; padding-top:0px; padding-bottom:0px; color:rgb(68,68,68); font-family:Tahoma,'Microsoft Yahei',Simsun; font-size:14px; line-height:28px; background-color:rgb(239,245,249)"> <span style="word-wrap:break-word; word-break:break-all; color:rgb(112,114,111)">ADC未被使用，ADC连接<br style="word-wrap:break-word; word-break:break-all"> 建议保持针对模拟电源引脚的连接，即便在ADC未被使用时也是如此。下面总结了如果ADC未在应用中使用，应该如何连接ADC引脚：<br style="word-wrap:break-word; word-break:break-all"> ? VDD1A18/VDD2A18-连接至VDD<br style="word-wrap:break-word; word-break:break-all"> ? VDDA2，VDDAIO-连接至VDDIO<br style="word-wrap:break-word; word-break:break-all"> ? VSS1AGND/VSS2AGND，VSSA2，VSSAIO-连接至VSS<br style="word-wrap:break-word; word-break:break-all"> ? ADCLO-连接至VSS<br style="word-wrap:break-word; word-break:break-all"> ? ADCREFIN-连接至VSS<br style="word-wrap:break-word; word-break:break-all"> ? ADCREFP/ADCREFM-连接一个100nF电容器至VSS<br style="word-wrap:break-word; word-break:break-all"> ? ADCRESEXT-连接一个20k?电阻器（非常松散的耐受）至VSS。<br style="word-wrap:break-word; word-break:break-all"> ? ADCINAn，ADC |
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