基本特點(diǎn)：

DS28EA00數(shù)字溫度傳感器是具有9位(0.5℃)至12位(1/16℃)分辨率和用戶(hù)可編程非易失性(NV)上、下觸發(fā)點(diǎn)報(bào)警功能的數(shù)字溫度計(jì)。每個(gè)DS28EA00都具工廠編程的唯一64位序列號(hào)。通信時(shí)只需一根數(shù)據(jù)線和地線，就可通過(guò)1-Wire?協(xié)議串行傳輸數(shù)據(jù)。改進(jìn)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(wǎng)絡(luò)中可靠工作。與其他1-Wire溫度計(jì)不同，DS28EA00具有兩個(gè)額外的引腳用以執(zhí)行順序檢測(cè)功能。該特性允許用戶(hù)將器件在鏈路中的物理位置與序列號(hào)對(duì)應(yīng)，例如，用來(lái)測(cè)量?jī)?chǔ)存塔不同高度處的溫度。如果無(wú)需順序檢測(cè)功能，這些引腳可作為通用輸入或輸出。DS28EA00能夠直接從數(shù)據(jù)線獲取電源進(jìn)行工作("寄生供電")，因此無(wú)需外部電源。

·數(shù)字溫度計(jì)測(cè)量范圍：-40℃至+85℃

·用戶(hù)可選擇的9至12位溫度分辨率

·獨(dú)特的1-Wire接口，僅需單個(gè)引腳即可進(jìn)行通信

·每個(gè)器件都具有在工廠激光刻蝕的唯一64位序列號(hào)

·ROM多節(jié)點(diǎn)能力簡(jiǎn)化分布式溫度檢測(cè)應(yīng)用

·具有滯回和干擾濾波器的改進(jìn)型1-Wire接口

·用戶(hù)可定義的非易失性(NV)報(bào)警溫度設(shè)置/用戶(hù)字節(jié)

·報(bào)警搜索命令能夠快速確定溫度超出設(shè)定范圍的器件

·標(biāo)準(zhǔn)和高速1-Wire通信模式

·2個(gè)通用可編程IO (PIO)引腳

·級(jí)聯(lián)功能使用PIO引腳檢測(cè)器件在網(wǎng)絡(luò)中的物理順序

·工作范圍：3.0V至5.5V，-40℃至+85℃

·可由數(shù)據(jù)線供電

方案特點(diǎn)

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

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圖2 參考layout top

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圖4： 參考layout composite