僅使用兩個(gè)模擬元件的靈活的plc／DC模擬輸出模塊

　　一些可編程邏輯控制器（PLC）和分布式控制系統(tǒng)（DCS）應(yīng)用需要一個(gè)功能齊全、靈活、可編程的模擬輸出解決方案。圖1所示的電路可以完成這一工作。它只有兩個(gè)模擬元件，滿足了PLC和DCS應(yīng)用的大部分要求。的ad5660-1低功率（2.8兆瓦@ 5 V），軌到軌輸出，16位?nanoDAC，結(jié)合ad5750-1工業(yè)電流/電壓輸出驅(qū)動(dòng)器，提供了所有典型的電流和電壓輸出范圍為16位分辨率和無(wú)失碼，0.05%度，小于0.1%的輸出誤差。該電路還包含工業(yè)應(yīng)用的關(guān)鍵特性，如片上輸出故障檢測(cè)、CRC校驗(yàn)以防止數(shù)據(jù)包錯(cuò)誤（PEC）和靈活的上電選項(xiàng)，這是魯棒工業(yè)控制系統(tǒng)的理想選擇。無(wú)需外部精密電阻或校準(zhǔn)程序，以保持在大批量生產(chǎn)一致的性能，從而使其成為PLC或DCS模塊的理想選擇。

　　Figure 1： Basic analog output circuit for single channel （simplified schematic， all connections and protection circuits not shown）。

　　Circuit description

　　The AD5750/AD5750-1 are single-channel， low cost， precision voltage/current output drivers developed to meet the requirements of industrial process control applications. The voltage output range can be programmed for the standard output ranges for PLC and DCS applications： 0 V to 5 V， 0 V to 10 V， ?5 V to +5 V， and ?10 V to +10 V. A 20 percent overrange setting is also provided for the standard ranges， giving the following options： 0 V to 6 V， 0 V to 12 V， ?6 V to +6 V， and ?12 V to +12 V.

　　The current output， which is provided on a separate pin， can be programmed for the ranges of 4 mA to 20 mA， 0 mA to 20 mA， ?20 mA to +20 mA， 0 mA to 24 mA， and ?24 mA to +24 mA. The unipolar ranges have a two percent overrange setting. Because the AD5750/AD5750-1 current output can either source or sink current， it can interface to a wide variety of sensors or actuators. The voltage and current output pins can be tied together to configure the end system as a single-channel output if desired.