|
簡介：采用支持菊鏈模式的新型數字溫度傳感器芯片DS28EA00組建的單總線測溫網絡。無需進行傳統的ROM搜索步驟，允許用戶將器件在鏈路中的物理位置與序列號對應，節省了RAM開銷，簡化了基于單總線的應用設計。 基本特點： DS28EA00數字溫度傳感器是具有9位(0.5℃)至12位(1/16℃)分辨率和用戶可編程非易失性(NV)上、下觸發點報警功能的數字溫度計。每個DS28EA00都具工廠編程的唯一64位序列號。通信時只需一根數據線和地線，就可通過1-Wire?協議串行傳輸數據。改進型1-Wire接口具有滯回和干擾濾波功能，使得DS28EA00能夠在大的1-Wire網絡中可靠工作。與其他1-Wire溫度計不同，DS28EA00具有兩個額外的引腳用以執行順序檢測功能。該特性允許用戶將器件在鏈路中的物理位置與序列號對應，例如，用來測量儲存塔不同高度處的溫度。如果無需順序檢測功能，這些引腳可作為通用輸入或輸出。DS28EA00能夠直接從數據線獲取電源進行工作("寄生供電")，因此無需外部電源。 ·數字溫度計測量范圍：-40℃至+85℃ ·用戶可選擇的9至12位溫度分辨率 ·獨特的1-Wire接口，僅需單個引腳即可進行通信 ·每個器件都具有在工廠激光刻蝕的唯一64位序列號 ·ROM多節點能力簡化分布式溫度檢測應用 ·具有滯回和干擾濾波器的改進型1-Wire接口 ·用戶可定義的非易失性(NV)報警溫度設置/用戶字節 ·報警搜索命令能夠快速確定溫度超出設定范圍的器件 ·標準和高速1-Wire通信模式 ·2個通用可編程IO (PIO)引腳 ·級聯功能使用PIO引腳檢測器件在網絡中的物理順序 ·工作范圍：3.0V至5.5V，-40℃至+85℃ ·可由數據線供電 方案特點 The DS28EA00 evaluation system (EV system) consists of a single evaluation kit (EV kit) that includes an evaluation board (EV board) made up of three subsections that can be broken/snapped off into three independently exercisable boards. Since one of the major features of the DS28EA00 is detection of physical sequence, a block of dip switches are provided on each subsection of the EV board to re-order the physical connection between the chips. Optionally, the customer can break off the subsections of the eval board, connect them together with the provided cables, and re-order the physical sequence of the DS28EA00s that way. Easy Setup Stand-Alone EV Board Contains Three Separate, Breakable Subsections with a DS28EA00 Per Subsection The Dipswitch Block on Each EV Board Subsection Routes Physical Chain-Mode Connections Between Chips When Used as a Stand-Alone Board EV Board’s Subsections are Breakable Into Three Separate Boards Each of Which Evaluates a Single DS28EA00 or, When Cabled Together, Evaluate Chain-Mode Searching LEDs Give Visual Indicators of PIO Activity 6-Pin Terminal Strip Allows PIO Testing Outside of Chain Mode PC Connectivity Included RoHS Compliant Free Downloadable Evaluation Software Available 參考原理圖 
圖1 參考原理圖 參考pcb圖
圖2 參考layout top
圖3 參考layout bottom
圖4： 參考layout composite 詳情請見： 
DS28EA00EVKIT.pdf
(3.88 MB)
（網絡） |
