DS2438.rar_ds2438 _hope_通讯编程文档下载-pudn.com

<html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta charset="utf-8"> <meta name="generator" content="pdf2htmlEX"> <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"> <link rel="stylesheet" href="https://static.pudn.com/base/css/base.min.css"> <link rel="stylesheet" href="https://static.pudn.com/base/css/fancy.min.css"> <link rel="stylesheet" href="https://static.pudn.com/prod/directory_preview_static/622b818615da9b288b989923/raw.css"> <script src="https://static.pudn.com/base/js/compatibility.min.js"></script> <script src="https://static.pudn.com/base/js/pdf2htmlEX.min.js"></script> <script> try{ pdf2htmlEX.defaultViewer = new pdf2htmlEX.Viewer({}); }catch(e){} </script> <title></title> </head> <body> <div id="sidebar" style="display: none"> <div id="outline"> </div> </div> <div id="pf1" class="pf w0 h0" data-page-no="1"><div class="pc pc1 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/622b818615da9b288b989923/bg1.jpg"><div class="t m0 x1 h2 y1 ff1 fs0 fc0 sc0 ls0 ws0"> <span class="_ _0"> </span>1 of 29<span class="_ _1"></span> <span class="_ _2"> </span> <span class="_ _3"> </span>070605 </div><div class="t m0 x2 h2 y2 ff1 fs0 fc0 sc0 ls1 ws1"> </div><div class="t m0 x2 h2 y3 ff1 fs0 fc0 sc0 ls1 ws1"> </div><div class="t m0 x2 h2 y4 ff1 fs0 fc0 sc0 ls1 ws1"> </div><div class="t m0 x2 h2 y5 ff1 fs0 fc0 sc0 ls1 ws1"> </div><div class="t m0 x2 h2 y6 ff1 fs0 fc0 sc0 ls1 ws1"><span class="fc3 sc0"> </span></div><div class="t m0 x2 h2 y7 ff1 fs0 fc0 sc0 ls1 ws1"> </div><div class="t m0 x2 h2 y8 ff1 fs0 fc0 sc0 ls1 ws1"> </div><div class="t m0 x2 h3 y9 ff1 fs1 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h4 ya ff2 fs2 fc0 sc0 ls2 ws1">FEATURES<span class="fc1 ls1"> </span></div><div class="t m0 x1 h3 yb ff3 fs1 fc0 sc0 ls1 ws1">§ <span class="_ _4"> </span><span class="ff1 ls3 ws2">Unique 1-Wire</span></div><div class="t m0 x3 h5 yc ff1 fs3 fc0 sc0 ls1 ws1">®</div><div class="t m0 x4 h3 yb ff4 fs1 fc0 sc0 ls1 ws1"> <span class="ff1 ls4 ws3">interface requir<span class="_ _4"></span>e<span class="_ _1"></span>s only one </span></div><div class="t m0 x5 h3 yd ff1 fs1 fc0 sc0 ls5 ws4">port pin for communication </div><div class="t m0 x1 h3 ye ff3 fs1 fc0 sc0 ls1 ws1">§ <span class="_ _4"> </span><span class="ff1 ls5 ws4">Provides unique 64-bit serial number </span></div><div class="t m0 x1 h3 yf ff3 fs1 fc0 sc0 ls1 ws1">§ <span class="_ _4"> </span><span class="ff1 ls6 ws5">Eliminates thermistor<span class="_ _1"></span>s by<span class="_ _1"></span> sensing battery </span></div><div class="t m0 x5 h3 y10 ff1 fs1 fc0 sc0 ls7 ws6">temperatur<span class="_ _4"></span>e on-chip </div><div class="t m0 x1 h3 y11 ff3 fs1 fc0 sc0 ls1 ws1">§ <span class="_ _4"> </span><span class="ff1 ls8 ws7">On-board A/D converter allows monitoring<span class="_ _1"></span> </span></div><div class="t m0 x5 h3 y12 ff1 fs1 fc0 sc0 ls9 ws8">of battery voltage for end-of-ch<span class="_ _4"></span>arge and end-</div><div class="t m0 x5 h3 y13 ff1 fs1 fc0 sc0 lsa ws9">of-discharge de<span class="_ _1"></span>termination </div><div class="t m0 x1 h3 y14 ff3 fs1 fc0 sc0 ls1 ws1">§ <span class="_ _4"> </span><span class="ff1 ls7 ws6">On-board integrat<span class="_ _4"></span>ed current accumulat<span class="_ _4"></span>or </span></div><div class="t m0 x5 h3 y15 ff1 fs1 fc0 sc0 lsb wsa">facilitate<span class="_ _1"></span>s fuel gauging<span class="_ _1"></span> </div><div class="t m0 x1 h3 y16 ff3 fs1 fc0 sc0 ls1 ws1">§ <span class="_ _4"> </span><span class="ff1 lsc wsb">Elapsed time mete<span class="_ _1"></span>r in binary format </span></div><div class="t m0 x1 h3 y17 ff3 fs1 fc0 sc0 ls1 ws1">§ <span class="_ _4"> </span><span class="ff1 ls4 ws3">40-byte nonvolatile user<span class="lsd wsc"> memory available </span></span></div><div class="t m0 x5 h3 y18 ff1 fs1 fc0 sc0 lse wsd">for storage of batter<span class="_ _4"></span>y<span class="_ _1"></span>-specific data </div><div class="t m0 x1 h3 y19 ff3 fs1 fc0 sc0 ls1 ws1">§ <span class="_ _4"> </span><span class="ff1 lsf wse">Reverts to low-power <span class="ls10 wsf">sleep mode on batter<span class="_ _4"></span>y<span class="_ _1"></span> </span></span></div><div class="t m0 x5 h3 y1a ff1 fs1 fc0 sc0 ls11 ws10">pack disconnect (feature <span class="_ _4"></span>disabled on </div><div class="t m0 x5 h3 y1b ff1 fs1 fc0 sc0 ls10 ws1">DS2438AZ) </div><div class="t m0 x1 h3 y1c ff3 fs1 fc0 sc0 ls1 ws1">§ <span class="_ _4"> </span><span class="ff1 ls12 ws11">Operating range -40ºC to +85ºC </span></div><div class="t m0 x1 h3 y1d ff3 fs1 fc0 sc0 ls1 ws1">§ <span class="_ _4"> </span><span class="ff1 ls4 ws3">Applications include portable computers, </span></div><div class="t m0 x5 h3 y1e ff1 fs1 fc0 sc0 ls13 ws12">portable/cellular phones, consumer </div><div class="t m0 x5 h3 y1f ff1 fs1 fc0 sc0 lsd wsc">electronics, and handhe<span class="ls14 ws13">ld instrumentation </span></div><div class="t m0 x6 h4 ya ff2 fs2 fc0 sc0 ls15 ws14">PIN A<span class="_ _1"></span>SSIGN<span class="_ _1"></span>MENT<span class="ff1 fs1 ls1 ws1"> </span></div><div class="t m0 x7 h6 y20 ff1 fs4 fc0 sc0 ls1 ws1"> </div><div class="t m0 x6 h4 y21 ff2 fs2 fc0 sc0 ls16 ws15">PIN DESCRIPTION </div><div class="t m0 x6 h3 y22 ff1 fs1 fc0 sc0 ls17 ws16">DQ - <span class="_ _5"></span>Data <span class="_ _6"></span>In/Out </div><div class="t m0 x6 h3 y23 ff1 fs1 fc0 sc0 ls11 ws10">VAD <span class="_ _7"> </span>- <span class="_ _8"> </span>General A/D input </div><div class="t m0 x6 h3 y24 ff1 fs1 fc0 sc0 ls1 ws1">V</div><div class="t m0 x8 h5 y25 ff1 fs3 fc0 sc0 ls18 ws1">SENS+</div><div class="t m0 x9 h3 y24 ff1 fs1 fc0 sc0 ls13 ws12"> <span class="_ _9"> </span>- <span class="_ _8"> </span>Battery current monitor input (+) </div><div class="t m0 x6 h3 y26 ff1 fs1 fc0 sc0 ls1 ws1">V</div><div class="t m0 x8 h5 y27 ff1 fs3 fc0 sc0 ls18 ws1">SENS-</div><div class="t m0 xa h3 y26 ff1 fs1 fc0 sc0 ls13 ws12"> <span class="_ _a"> </span>- <span class="_ _8"> </span>Battery current monitor input (-) </div><div class="t m0 x6 h3 y28 ff1 fs1 fc0 sc0 ls11 ws10">VDD <span class="_ _7"> </span>- <span class="_ _8"> </span>Power Supply (2.4V to 10.0V) </div><div class="t m0 x6 h3 y29 ff1 fs1 fc0 sc0 ls19 ws17">GND - <span class="_ _b"></span> <span class="_ _c"></span>Ground </div><div class="t m0 x6 h3 y2a ff1 fs1 fc0 sc0 ls3 ws2">NC <span class="_ _d"> </span>- <span class="_ _8"> </span>No connect </div><div class="t m0 x6 h7 y2b ff1 fs2 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h4 y2c ff2 fs2 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h4 y2d ff2 fs2 fc0 sc0 ls1a ws18">DESCRIPTION <span class="_ _4"></span> </div><div class="t m0 x1 h3 y2e ff1 fs1 fc0 sc0 ls5 ws19">The DS2438 Smart Battery Monitor provides several fun<span class="_ _4"></span>c<span class="_ _1"></span><span class="ls1b ws1a">tions that are desirable to <span class="_ _4"></span>carry in a battery </span></div><div class="t m0 x1 h3 y2f ff1 fs1 fc0 sc0 ls1c ws1b">pack: a mea<span class="_ _1"></span>ns of tagging<span class="_ _1"></span> a battery pack with a uni<span class="ls1b ws1c">que serial number, a dire<span class="ls1d ws1d">ct-to-digita<span class="_ _1"></span>l temperature<span class="_ _1"></span> </span></span></div><div class="t m0 x1 h3 y30 ff1 fs1 fc0 sc0 ls4 ws1e">sensor which eliminates the need for thermistors in <span class="ls1b ws1f">the battery pack, an A/D converte<span class="_ _4"></span>r which measures </span></div><div class="t m0 x1 h3 y31 ff1 fs1 fc0 sc0 lsd ws20">the battery voltage and current, an integrated curre<span class="ls13 ws21">nt accumulator whic<span class="_ _4"></span>h keeps a running<span class="_ _1"></span> total of all </span></div><div class="t m0 x1 h3 y32 ff1 fs1 fc0 sc0 ls13 ws22">current going into and o<span class="_ _4"></span>ut of the battery, an el<span class="lsd ws23">apsed time meter, <span class="_ _4"></span>and 40 by<span class="ls1e ws24">tes of nonvolatile EEPROM </span></span></div><div class="t m0 x1 h3 y33 ff1 fs1 fc0 sc0 lsd ws25">memory for storage of important paramet<span class="_ _4"></span>ers such <span class="ls1f ws26">as batter<span class="_ _4"></span>y<span class="_ _1"></span> chemistr<span class="_ _4"></span>y<span class="_ _1"></span>, batter<span class="_ _4"></span>y<span class="_ _1"></span> capacit<span class="_ _4"></span>y<span class="_ _1"></span>, char<span class="_ _4"></span>g<span class="_ _1"></span>ing </span></div><div class="t m0 x1 h3 y34 ff1 fs1 fc0 sc0 ls12 ws27">methodology and assembly date. <span class="_ _4"></span>I<span class="_ _1"></span>nformation is sent<span class="ls13 ws28"> to/from the <span class="_ _4"></span>DS2438 over a 1-Wire interfa<span class="_ _4"></span>ce, so that </span></div><div class="t m0 x1 h3 y35 ff1 fs1 fc0 sc0 ls11 ws29">only one wire (and <span class="_ _4"></span>g<span class="_ _1"></span>round) needs to be<span class="_ _4"></span> connected<span class="ls1b ws1a"> from a central<span class="_ _4"></span> microprocessor to a DS2438. <span class="_ _4"></span> This </span></div><div class="t m0 x1 h3 y36 ff1 fs1 fc0 sc0 ls11 ws2a">means that batter<span class="_ _4"></span>y<span class="_ _1"></span> packs need onl<span class="_ _4"></span>y<span class="_ _1"></span> have three ou<span class="_ _4"></span>tput connectors: battery power, ground, and<span class="_ _4"></span> the 1-Wire </div><div class="t m0 x1 h3 y37 ff1 fs1 fc0 sc0 ls20 ws1">interfa<span class="_ _1"></span>ce. </div><div class="t m0 x1 h2 y38 ff1 fs0 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h3 y39 ff1 fs1 fc0 sc0 ls8 ws2b">Because each DS2438 c<span class="_ _4"></span>ontains a uni<span class="ls1 ws2c">que silicon serial number, multiple<span class="ls12 ws2d"> DS2438s can ex<span class="_ _4"></span>ist on the same </span></span></div><div class="t m0 x1 h3 y3a ff1 fs1 fc0 sc0 lsc wsb">1-Wire bus. This allows multiple<span class="_ _1"></span> battery<span class="_ _1"></span> packs to be<span class="_ _1"></span> charged or used in the sy<span class="_ _1"></span>stem simultane<span class="_ _1"></span>ously. </div><div class="t m0 x1 h2 y3b ff1 fs0 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h3 y3c ff1 fs1 fc0 sc0 lsf ws2e">Applications for the smart battery monitor include <span class="lsd ws2f">portable computers, cellula<span class="ls11 ws2a">r telephones, and handheld </span></span></div><div class="t m0 x1 h3 y3d ff1 fs1 fc0 sc0 ls21 ws30">instrumentation ba<span class="_ _1"></span>ttery<span class="_ _1"></span> packs in which it is cr<span class="_ _1"></span>itical to monitor rea<span class="_ _1"></span>l-time battery<span class="_ _1"></span> performa<span class="_ _1"></span>nce. Used in </div><div class="t m0 x1 h3 y3e ff1 fs1 fc0 sc0 ls5 ws31">conjunction with a microcontroller in the host syst<span class="ls8 ws32">em, the DS2438 provides a complete smart batter<span class="_ _4"></span>y<span class="_ _1"></span> </span></div><div class="t m0 x1 h3 y3f ff1 fs1 fc0 sc0 ls22 ws33">pack solution that is fully<span class="_ _1"></span> chemistry<span class="_ _1"></span>-independent. <span class="ls23 ws34">The customiza<span class="_ _1"></span>tion for a pa<span class="_ _1"></span>rticular battery<span class="_ _1"></span> chemistry<span class="_ _1"></span> </span></div><div class="t m0 x1 h3 y40 ff1 fs1 fc0 sc0 ls4 ws35">and capacity is realized in the code programme<span class="ls12 ws36">d into the microcontroller and DS2438 EEPROM, and<span class="_ _1"></span> </span></div><div class="t m0 x1 h3 y41 ff1 fs1 fc0 sc0 ls4 ws3">only a software revision is necessar<span class="_ _4"></span>y<span class="_ _1"></span> should a desi<span class="ls8 ws37">gner wish to change battery pack ch<span class="_ _4"></span>emistry<span class="_ _1"></span>. </span></div><div class="t m0 xb h8 y42 ff2 fs5 fc0 sc0 ls24 ws1">DS2438</div><div class="t m0 xc h8 y43 ff2 fs5 fc0 sc0 ls25 ws38">Smart Battery Monito</div><div class="c xc y44 w2 h9"><div class="t m0 xd h8 y45 ff2 fs5 fc0 sc0 ls1 ws1">r</div></div><div class="t m0 xe ha y46 ff5 fs6 fc0 sc0 ls1 ws1"> </div><div class="t m0 xf hb y47 ff2 fs1 fc2 sc0 ls1d ws1">www<span class="_ _1"></span>.max<span class="_ _1"></span>im-ic.<span class="_ _1"></span>com </div><div class="t m0 x10 hc y48 ff6 fs3 fc0 sc0 ls26 ws39"> GND</div><div class="t m0 x11 hc y49 ff6 fs3 fc0 sc0 ls1 ws1">V</div><div class="t m0 x12 hd y4a ff6 fs4 fc0 sc0 ls27 ws1">SENS+</div><div class="t m0 x10 hc y4b ff6 fs3 fc0 sc0 ls1 ws1">V</div><div class="t m0 x13 hd y4c ff6 fs4 fc0 sc0 ls27 ws1">SENS-</div><div class="t m0 x14 hc y4d ff6 fs3 fc0 sc0 ls1 ws1">V</div><div class="c x15 y4e w3 he"><div class="t m0 x0 hd y4f ff6 fs4 fc0 sc0 ls1 ws1">A</div></div><div class="t m0 x16 hd y50 ff6 fs4 fc0 sc0 ls1 ws1">D</div><div class="t m0 x17 hc y48 ff6 fs3 fc0 sc0 ls26 ws1">DQ </div><div class="t m0 x17 hc y49 ff6 fs3 fc0 sc0 ls28 ws1">NC </div><div class="t m0 x17 hc y51 ff6 fs3 fc0 sc0 ls28 ws1">NC </div><div class="t m0 x17 hc y52 ff6 fs3 fc0 sc0 ls1 ws1">V</div><div class="t m0 x18 hd y53 ff6 fs4 fc0 sc0 ls29 ws1">DD</div><div class="t m0 x19 hc y50 ff6 fs3 fc0 sc0 ls1 ws1"> </div><div class="t m0 x17 hc y54 ff6 fs3 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1a hc y55 ff6 fs3 fc0 sc0 ls1 ws1">1</div><div class="t m0 x1a hc y56 ff6 fs3 fc0 sc0 ls1 ws1">2</div><div class="t m0 x1a hc y57 ff6 fs3 fc0 sc0 ls1 ws1">3</div><div class="t m0 x1a hc y58 ff6 fs3 fc0 sc0 ls1 ws1">4</div><div class="t m0 x1b hc y59 ff6 fs3 fc0 sc0 ls2a ws1">8 </div><div class="t m0 x1b hc y5a ff6 fs3 fc0 sc0 ls2a ws1">7 </div><div class="t m0 x1b hc y5b ff6 fs3 fc0 sc0 ls2a ws1">6 </div><div class="t m0 x1b hc y5c ff6 fs3 fc0 sc0 ls2a ws1">5 </div><div class="t m0 x16 hf y5d ff6 fs0 fc0 sc0 ls2b ws3a">DS2438Z, DS<span class="_ _4"></span>2438AZ </div><div class="t m0 x1c hf y5e ff6 fs0 fc0 sc0 ls2c ws3b">8-Pin SOIC<span class="_ _4"></span> (150-m<span class="_ _4"></span>il)<span class="ff1 ls1 ws1"> </span></div></div><div class="pi" data-data='{"ctm":[1.568627,0.000000,0.000000,1.568627,0.000000,0.000000]}'></div></div> </body> </html>

<div id="pf2" class="pf w0 h0" data-page-no="2"><div class="pc pc2 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/622b818615da9b288b989923/bg2.jpg"><div class="t m0 x1d h2 y5f ff1 fs0 fc0 sc0 ls2d ws1">DS2438 </div><div class="t m0 x1e h2 y60 ff1 fs0 fc0 sc0 ls2e ws3c"> <span class="_ _e"> </span>2 of 29 </div><div class="t m0 x1 h4 y61 ff2 fs2 fc0 sc0 ls2f ws3d">ORDERING INFORM<span class="_ _4"></span>A<span class="_ _1"></span>TION </div><div class="t m0 x1f h10 y62 ff5 fs1 fc0 sc0 lsd ws3e">PART MARKING <span class="_ _f"> </span>PACKAGE <span class="_ _10"></span>INFORMATION </div><div class="t m0 x20 h3 y63 ff1 fs1 fc0 sc0 ls1e ws3f">DS2438Z+ DS2438 <span class="_ _11"></span>8-Pin <span class="_ _12"></span>SOIC </div><div class="t m0 x21 h3 y64 ff1 fs1 fc0 sc0 ls4 ws3">DS2438Z+T&R <span class="_ _13"> </span>DS2438 <span class="_ _14"> </span>DS2438Z+ on Tape-and-Reel </div><div class="t m0 x21 h3 y65 ff1 fs1 fc0 sc0 ls1e ws40">DS2438AZ+ DS2438A <span class="_ _15"></span>8-Pin <span class="_ _16"></span>SOIC </div><div class="t m0 x21 h3 y66 ff1 fs1 fc0 sc0 ls4 ws3">DS2438AZ+T&R <span class="_ _17"> </span>DS2438A <span class="_ _18"> </span>DS2438AZ+ on Tape-and-Reel </div><div class="t m0 x21 h3 y67 ff1 fs1 fc0 sc0 ls30 ws41">DS2438Z DS2438 <span class="_ _19"></span>8-Pin <span class="_ _1a"></span>SOIC </div><div class="t m0 x21 h3 y68 ff1 fs1 fc0 sc0 ls1 ws1">DS2438Z/T&R <span class="_ _1b"> </span>DS2438 <span class="_ _14"> </span>DS2438Z on Tape-and-Reel </div><div class="t m0 x21 h3 y69 ff1 fs1 fc0 sc0 ls14 ws42">DS2438AZ DS2438A <span class="_ _1c"></span>8-Pin <span class="_ _1d"></span>SOIC </div><div class="t m0 x21 h3 y6a ff1 fs1 fc0 sc0 ls10 wsf">DS2438AZ/T&R <span class="_ _1e"> </span>DS2438A <span class="_ _18"> </span>DS2438AZ on Tape-and-Reel </div><div class="t m0 x1 h11 y6b ff7 fs0 fc0 sc0 ls31 ws43">+ Denotes l<span class="_ _1"></span>ead-free package.<span class="_ _1"></span> </div><div class="t m0 x1 h2 y6c ff1 fs0 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h4 y6d ff2 fs2 fc0 sc0 ls32 ws44">DETAILED PIN DESCRIPTION </div><div class="t m0 x2 h10 y6e ff5 fs1 fc0 sc0 ls9 ws45">PIN SYMBOL <span class="_ _1f"></span>DESCRIPTION </div><div class="t m0 x22 h3 y6f ff1 fs1 fc0 sc0 ls19 ws46">1 GND </div><div class="t m0 x23 h10 y70 ff5 fs1 fc0 sc0 ls33 ws1">Ground </div><div class="t m0 x22 h3 y71 ff1 fs1 fc0 sc0 ls1 ws47">2 V</div><div class="t m0 x24 h5 y72 ff1 fs3 fc0 sc0 ls18 ws1">SENS+</div><div class="t m0 x25 h3 y71 ff1 fs1 fc0 sc0 ls1 ws1"> <span class="_ _20"> </span><span class="ff5 ls20 ws48">Batter<span class="_ _1"></span>y Input:<span class="ff1 ls11 ws10"> connection for battery current to be monitored (see t<span class="_ _4"></span>ext) </span></span></div><div class="t m0 x22 h3 y73 ff1 fs1 fc0 sc0 ls1 ws49">3 V</div><div class="t m0 x26 h5 y74 ff1 fs3 fc0 sc0 ls18 ws1">SENS-</div><div class="t m0 x27 h3 y73 ff1 fs1 fc0 sc0 ls1 ws1"> <span class="_ _d"> </span><span class="ff5 ls20 ws48">Batter<span class="_ _1"></span>y Input:<span class="ff1 ls11 ws10"> connection for battery current to be monitored (see t<span class="_ _4"></span>ext) </span></span></div><div class="t m0 x22 h3 y75 ff1 fs1 fc0 sc0 ls1 ws4a">4 V</div><div class="t m0 x28 h5 y76 ff1 fs3 fc0 sc0 ls34 ws1">AD</div><div class="t m0 x29 h3 y75 ff1 fs1 fc0 sc0 ls1 ws1"> <span class="_ _21"> </span><span class="ff5">ADC Input:</span><span class="lsd ws4b"> input for general purpose A/D </span></div><div class="t m0 x22 h3 y77 ff1 fs1 fc0 sc0 ls1 ws4a">5 V</div><div class="t m0 x28 h5 y78 ff1 fs3 fc0 sc0 ls34 ws1">DD</div><div class="t m0 x29 h3 y77 ff1 fs1 fc0 sc0 ls1 ws1"> <span class="_ _21"> </span><span class="ff5">V</span></div><div class="t m0 x2a h12 y78 ff5 fs3 fc0 sc0 ls34 ws1">DD</div><div class="t m0 x2b h3 y77 ff5 fs1 fc0 sc0 ls35 ws4c"> Pin<span class="_ _4"></span>:<span class="ff1 ls36 ws4d"> input supply voltage </span></div><div class="t m0 x2c h3 y79 ff1 fs1 fc0 sc0 ls37 ws4e">6, 7 <span class="_ _22"> </span>NC </div><div class="t m0 x23 h10 y7a ff5 fs1 fc0 sc0 ls38 ws4f">No Connect </div><div class="t m0 x22 h3 y7b ff1 fs1 fc0 sc0 lse ws50">8 DQ <span class="_ _23"></span><span class="ff5 ls39 ws51">Data Input<span class="_ _1"></span>/Out:<span class="ff1 ls1b ws52"> for 1-Wire operation: Open drain </span></span></div><div class="t m0 x1 h3 y7c ff1 fs1 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h4 y7d ff2 fs2 fc0 sc0 ls3a ws1">OVERVIEW </div><div class="t m0 x1 h3 y7e ff1 fs1 fc0 sc0 lsf wse">The block diagram of Figure 1 shows th<span class="ls13 ws12">e seven major components of the D<span class="_ _4"></span>S2438: </span></div><div class="t m0 x1 h3 y7f ff1 fs1 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h3 y80 ff1 fs1 fc0 sc0 ls12 ws11">1. <span class="_ _24"> </span>64-bit lasered ROM </div><div class="t m0 x1 h3 y81 ff1 fs1 fc0 sc0 ls1b ws53">2. temperature <span class="_ _25"></span>sensor </div><div class="t m0 x1 h3 y82 ff1 fs1 fc0 sc0 ls10 wsf">3. <span class="_ _24"> </span>battery voltage A/D </div><div class="t m0 x1 h3 y83 ff1 fs1 fc0 sc0 ls8 ws37">4. <span class="_ _24"> </span>battery current A/D </div><div class="t m0 x1 h3 y84 ff1 fs1 fc0 sc0 ls3b ws54">5. current <span class="_ _25"></span>accumulators </div><div class="t m0 x1 h3 y85 ff1 fs1 fc0 sc0 ls22 ws55">6. <span class="_ _24"> </span>elapsed time me<span class="_ _1"></span>ter </div><div class="t m0 x1 h3 y86 ff1 fs1 fc0 sc0 lsf wse">7. <span class="_ _24"> </span>40-byte nonvolatile user-memory </div><div class="t m0 x1 h2 y87 ff1 fs0 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h3 y88 ff1 fs1 fc0 sc0 lsf ws56">Each DS2438 contains a unique 64-bit <span class="ls11 ws57">lasered ROM serial number so that<span class="ls1b ws1f"> several battery packs can be </span></span></div><div class="t m0 x1 h3 y89 ff1 fs1 fc0 sc0 ls5 ws58">charged/monitored by the same host s<span class="_ _4"></span>y<span class="_ _1"></span>stem. Furthe<span class="ws59">rmore, other Dallas products featuring the same </span></div><div class="t m0 x1 h3 y8a ff1 fs1 fc0 sc0 lsa ws5a">1-Wire bus ar<span class="_ _1"></span>chitecture with a 64-bit ROM c<span class="_ _1"></span>an reside<span class="_ _1"></span> on the same bus; refer to the<span class="_ _1"></span> Dallas Automatic<span class="_ _1"></span> </div><div class="t m0 x1 h3 y8b ff1 fs1 fc0 sc0 ls4 ws3">Identification Data book<span class="ls9 ws8"> for the speci<span class="_ _4"></span>fications of these products. </span></div><div class="t m0 x1 h2 y8c ff1 fs0 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h3 y8d ff1 fs1 fc0 sc0 ls5 ws5b">Communication to the DS2438 is via a 1-Wire port. <span class="_ _4"></span><span class="lsd ws5c">With the 1-Wire port, the memory and control </span></div><div class="t m0 x1 h3 y8e ff1 fs1 fc0 sc0 ls6 ws5d">functions will not be available until the<span class="_ _1"></span> ROM function protocol has been e<span class="_ _1"></span>stablished. The master must </div><div class="t m0 x1 h3 y8f ff1 fs1 fc0 sc0 lsf wse">first provide one of four<span class="_ _4"></span> ROM func<span class="ls10 wsf">tion commands: 1) Read ROM, 2) Ma<span class="ls12 ws11">t<span class="_ _4"></span>ch ROM, 3) Search ROM, or 4) </span></span></div><div class="t m0 x1 h3 y90 ff1 fs1 fc0 sc0 ls4 ws5e">Skip ROM. These commands operate on the 64-bit lasered ROM portion of each device and can singulate </div><div class="t m0 x1 h3 y91 ff1 fs1 fc0 sc0 ls1f ws5f">a specific devi<span class="_ _4"></span>ce if many are present<span class="_ _4"></span> on the 1-Wir<span class="_ _4"></span>e line as well as to indi<span class="_ _4"></span>cate to the bus master ho<span class="_ _4"></span>w many </div><div class="t m0 x1 h3 y92 ff1 fs1 fc0 sc0 ls19 ws60">and what types of devices are present. After a R<span class="_ _4"></span>O<span class="ls9 ws61">M function sequence has been successfully executed, </span></div><div class="t m0 x1 h3 y93 ff1 fs1 fc0 sc0 ls17 ws62">the memory and control funct<span class="_ _4"></span>ions are accessible and the master ma<span class="_ _4"></span>y<span class="_ _26"></span> then provide an<span class="_ _4"></span>y<span class="_ _26"></span> one<span class="_ _4"></span> <span class="_ _1"></span>of the six </div><div class="t m0 x1 h3 y94 ff1 fs1 fc0 sc0 ls10 wsf">memory and control function commands. </div><div class="t m0 x1 h2 y95 ff1 fs0 fc0 sc0 ls1 ws1"> </div></div><div class="pi" data-data='{"ctm":[1.568627,0.000000,0.000000,1.568627,0.000000,0.000000]}'></div></div>

<div id="pf3" class="pf w0 h0" data-page-no="3"><div class="pc pc3 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/622b818615da9b288b989923/bg3.jpg"><div class="t m0 x1d h2 y5f ff1 fs0 fc0 sc0 ls2d ws1">DS2438 </div><div class="t m0 x1e h2 y60 ff1 fs0 fc0 sc0 ls2e ws3c"> <span class="_ _e"> </span>3 of 29 </div><div class="t m0 x1 h3 y96 ff1 fs1 fc0 sc0 ls10 ws63">Control function commands may be issued which <span class="ls21 ws64">instruct the DS2438 to perform a temper<span class="_ _1"></span>ature </span></div><div class="t m0 x1 h3 y97 ff1 fs1 fc0 sc0 ls3c ws65">measuremen<span class="_ _1"></span>t or battery voltag<span class="_ _1"></span>e A/D conversion. The result of the<span class="_ _1"></span>se measure<span class="_ _1"></span>ments will be plac<span class="_ _1"></span>ed in the </div><div class="t m0 x1 h3 y98 ff1 fs1 fc0 sc0 ls10 ws66">DS2438’s memory<span class="_ _1"></span> map, and ma<span class="_ _4"></span>y<span class="_ _26"></span> be read b<span class="_ _4"></span>y<span class="_ _26"></span> issu<span class="ls8 ws67">ing a memory function command which reads the </span></div><div class="t m0 x1 h3 y99 ff1 fs1 fc0 sc0 ls3d ws68">contents of the te<span class="_ _1"></span>mperature an<span class="_ _1"></span>d voltage registers. Additionally<span class="_ _1"></span>, the charg<span class="_ _26"></span>ing/discharging batte<span class="_ _1"></span>ry current is </div><div class="t m0 x1 h3 y9a ff1 fs1 fc0 sc0 ls8 ws69">measured without user i<span class="_ _4"></span>ntervention, and again, the la<span class="ls1 ws6a">st completed result is stored in DS2438 m<span class="_ _4"></span>emory<span class="_ _1"></span> </span></div><div class="t m0 x1 h3 y9b ff1 fs1 fc0 sc0 lsd ws4c">space. The DS2438 uses <span class="_ _4"></span>these current measurements to <span class="ls11">update three curr<span class="_ _4"></span>ent accumulators; the first stores </span></div><div class="t m0 x1 h3 y9c ff1 fs1 fc0 sc0 ls3e ws6b">net charg<span class="_ _1"></span>e for fuel gauge calcula<span class="_ _1"></span>tions, the second accumula<span class="_ _1"></span>tes the total charg<span class="_ _26"></span>i<span class="_ _4"></span>ng c<span class="_ _1"></span>urrent over the life of </div><div class="t m0 x1 h3 y9d ff1 fs1 fc0 sc0 ls3e ws6c">the battery<span class="_ _1"></span>, and the remaining ac<span class="_ _1"></span>cumulator ta<span class="_ _1"></span>llies battery<span class="_ _1"></span> discharge curre<span class="_ _1"></span>nt. The elapsed time me<span class="_ _1"></span>ter data, </div><div class="t m0 x1 h3 y9e ff1 fs1 fc0 sc0 ls1c ws6d">which can be used in calcula<span class="_ _1"></span>ting battery<span class="_ _1"></span> self-discharge or time<span class="_ _1"></span>-relate<span class="_ _1"></span>d charge termination limits, also </div><div class="t m0 x1 h3 y9f ff1 fs1 fc0 sc0 ls8 ws6e">resides in the DS2438 memory<span class="_ _1"></span> map and can be ex<span class="lsd ws6f">tracted with a memor<span class="_ _4"></span>y<span class="_ _26"></span> function command. The </span></div><div class="t m0 x1 h3 ya0 ff1 fs1 fc0 sc0 ls5 ws70">nonvolatile user memory of the DS2438 <span class="ls10 ws71">consists <span class="_ _1"></span>of 40 bytes of EEPROM. These locations may<span class="_ _1"></span> be used </span></div><div class="t m0 x1 h3 ya1 ff1 fs1 fc0 sc0 ls9 ws72">to store an<span class="_ _4"></span>y<span class="_ _26"></span> data<span class="_ _4"></span> the user wishes and ar<span class="_ _4"></span>e writte<span class="ls12 ws73">n to using a memor<span class="_ _4"></span>y<span class="_ _26"></span> fu<span class="_ _4"></span>nction command. All data and </span></div><div class="t m0 x1 h3 ya2 ff1 fs1 fc0 sc0 ls22 ws55">commands are<span class="_ _1"></span> read and written least sig<span class="_ _1"></span>nificant bit first. </div><div class="t m0 x1 h4 ya3 ff2 fs2 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h4 ya4 ff2 fs2 fc0 sc0 ls3f ws74">PARA<span class="_ _1"></span>SITE POWER </div><div class="t m0 x1 h3 ya5 ff1 fs1 fc0 sc0 ls8 ws75">The block diagram (Fi<span class="_ _4"></span>g<span class="_ _26"></span>ur<span class="_ _4"></span>e 1) shows the parasite-pow<span class="ls40 ws76">ered <span class="_ _4"></span>circuitry. This ci<span class="_ _4"></span>rcuitry “steals”<span class="_ _4"></span> power </span></div><div class="t m0 x1 h3 ya6 ff1 fs1 fc0 sc0 ls8 ws77">whenever the DQ pin is high. DQ will provide sufficient power as long as the specified timing and<span class="_ _4"></span> </div><div class="t m0 x1 h3 ya7 ff1 fs1 fc0 sc0 ls21 ws78">voltage<span class="_ _1"></span> requirements ar<span class="_ _1"></span>e met (see<span class="_ _1"></span> the section title<span class="_ _1"></span>d “1-Wire B<span class="_ _26"></span>us S<span class="_ _4"></span>y<span class="_ _1"></span>stem”). The adva<span class="_ _1"></span>ntage of parasite<span class="_ _1"></span> </div><div class="t m0 x1 h3 ya8 ff1 fs1 fc0 sc0 ls41 ws79">power is that th<span class="_ _4"></span>e ROM may be read in <span class="_ _4"></span>absence of nor<span class="lsb ws7a">mal power, i.e., if the battery<span class="_ _1"></span> pack is completely </span></div><div class="t m0 x1 h3 ya9 ff1 fs1 fc0 sc0 lsd ws1">discharged. </div><div class="t m0 x1 h3 yaa ff1 fs1 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h13 yab ff2 fs2 fc0 sc0 ls16 ws15">DS2438 BLOCK DIA<span class="_ _1"></span>GR<span class="_ _4"></span>A<span class="_ _26"></span>M<span class="_ _4"></span> <span class="ff6 ls3f ws74">Figure 1 </span></div><div class="t m0 x1 h3 yac ff1 fs1 fc0 sc0 ls1 ws1"> </div><div class="t m0 x2d h2 yad ff1 fs0 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h3 yae ff1 fs1 fc0 sc0 ls1 ws1"> </div></div><div class="pi" data-data='{"ctm":[1.568627,0.000000,0.000000,1.568627,0.000000,0.000000]}'></div></div>

<div id="pf4" class="pf w0 h0" data-page-no="4"><div class="pc pc4 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/622b818615da9b288b989923/bg4.jpg"><div class="t m0 x1d h2 y5f ff1 fs0 fc0 sc0 ls2d ws1">DS2438 </div><div class="t m0 x1e h2 y60 ff1 fs0 fc0 sc0 ls2e ws3c"> <span class="_ _e"> </span>4 of 29 </div><div class="t m0 x1 h4 y61 ff2 fs2 fc0 sc0 ls42 ws7b">OPERATION-MEASURING TEM<span class="_ _4"></span>PER<span class="_ _26"></span>ATURE </div><div class="t m0 x1 h3 yaf ff1 fs1 fc0 sc0 ls13 ws12">The DS2438 measures temperatures throu<span class="_ _4"></span>g<span class="_ _1"></span>h the use of<span class="lsd ws4b"> an on-bo<span class="_ _4"></span>ard temperature measurement techn<span class="_ _4"></span>ique. </span></div><div class="t m0 x1 h3 yb0 ff1 fs1 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h3 yb1 ff1 fs1 fc0 sc0 lsd ws7c">The temperature re<span class="_ _4"></span>ading is provided in a 13-bit,<span class="ls4 ws7d"> two’s complement format<span class="_ _4"></span>, which provides 0.03125<span class="ff8 ls1 ws1">°</span><span class="lsb ws7e">C of </span></span></div><div class="t m0 x1 h3 yb2 ff1 fs1 fc0 sc0 ls1b ws7f">resolution. Table 1 describes the exact<span class="_ _4"></span><span class="ls10 ws80"> relationship of output data to m<span class="lse ws81">easured temperature. The data is </span></span></div><div class="t m0 x1 h3 yb3 ff1 fs1 fc0 sc0 ls13 ws82">transmitted seriall<span class="_ _4"></span>y<span class="_ _26"></span> over<span class="_ _4"></span> the 1-Wire interface. The DS2438 c<span class="_ _4"></span>a<span class="_ _1"></span>n measure temperatur<span class="_ _4"></span>e over the range of </div><div class="t m0 x1 h3 yb4 ff1 fs1 fc0 sc0 ls19 ws1">-55<span class="ff8 ls1">°</span><span class="ls43 ws83">C to +125</span><span class="ff8 ls1">°</span><span class="ls44 ws84">C in 0.03125</span><span class="ff8 ls1">°</span><span class="ls8 ws69">C increments. <span class="_ _4"></span>For Fahrenheit usage, a lookup table o<span class="_ _4"></span>r conversion factor </span></div><div class="t m0 x1 h3 yb5 ff1 fs1 fc0 sc0 ls10 wsf">must be used. </div><div class="t m0 x1 h3 yb6 ff1 fs1 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h3 yb7 ff1 fs1 fc0 sc0 ls19 ws85">Note that temperature is repres<span class="_ _4"></span>en<span class="ls5 ws86">ted in the DS2438 in terms of a 0.03125<span class="_ _4"></span><span class="ff8 ls1 ws1">°</span><span class="ls1e ws87">C L<span class="_ _26"></span>S<span class="_ _4"></span>b, y<span class="_ _26"></span>i<span class="_ _4"></span>elding the following </span></span></div><div class="t m0 x1 h3 yb8 ff1 fs1 fc0 sc0 ls6 ws88">13-bit format. The 3 least sig<span class="_ _1"></span>nifican<span class="_ _1"></span>t bits of the Temperature Reg<span class="_ _1"></span>ister will always be 0. The remaining </div><div class="t m0 x1 h3 yb9 ff1 fs1 fc0 sc0 lsa ws89">13 <span class="_ _26"></span>bits conta<span class="_ _1"></span>in the two’s compleme<span class="_ _1"></span>nt represe<span class="_ _1"></span>ntation of the tempera<span class="_ _1"></span>ture in <span class="ff8 ls1 ws1">°</span><span class="ls37 ws8a">C, with the MSb holding the </span></div><div class="t m0 x1 h3 yba ff1 fs1 fc0 sc0 ls8 ws37">sign (S) bit. See “Memory Map” section for the Temperatur<span class="_ _4"></span>e Register address location. </div><div class="t m0 x1 h14 ybb ff6 fs1 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h13 ybc ff2 fs2 fc0 sc0 ls45 ws8b">Temperature Register Format <span class="_ _4"></span><span class="ff6 ls46 ws8c">Table<span class="_ _26"></span> 1 </span></div><div class="t m0 x1 h5 ybd ff1 fs3 fc0 sc0 ls1 ws1"> </div><div class="t m0 x29 h2 ybe ff1 fs0 fc0 sc0 ls1 ws1">2</div><div class="t m0 x27 h15 ybf ff1 fs7 fc0 sc0 ls47 ws1">-1</div><div class="t m0 x2e h2 ybe ff1 fs0 fc0 sc0 ls48 ws1"> 2</div><div class="t m0 x2f h15 ybf ff1 fs7 fc0 sc0 ls47 ws1">-2</div><div class="t m0 x30 h2 ybe ff1 fs0 fc0 sc0 ls48 ws1"> 2</div><div class="t m0 x31 h15 ybf ff1 fs7 fc0 sc0 ls47 ws1">-3</div><div class="t m0 x32 h2 ybe ff1 fs0 fc0 sc0 ls49 ws1"> 2</div><div class="t m0 x33 h15 ybf ff1 fs7 fc0 sc0 ls47 ws1">-4</div><div class="t m0 x34 h2 ybe ff1 fs0 fc0 sc0 ls48 ws1"> 2</div><div class="t m0 x35 h15 ybf ff1 fs7 fc0 sc0 ls47 ws1">-5</div><div class="t m0 x36 h2 ybe ff1 fs0 fc0 sc0 ls4a ws8d"> 0 <span class="_ _27"> </span>0 <span class="_ _27"> </span>0 LSB </div><div class="t m0 x37 h3 yc0 ff1 fs1 fc0 sc0 ls12 ws11">MSb <span class="_ _28"> </span>(unit = °C) <span class="_ _29"> </span>LSb </div><div class="t m0 x38 h2 yc1 ff1 fs0 fc0 sc0 ls4b ws8e">S 2</div><div class="t m0 x23 h15 yc2 ff1 fs7 fc0 sc0 ls1 ws1">6</div><div class="t m0 x39 h2 yc1 ff1 fs0 fc0 sc0 ls4c ws1"> 2</div><div class="t m0 x3a h15 yc2 ff1 fs7 fc0 sc0 ls1 ws1">5</div><div class="t m0 x3b h2 yc1 ff1 fs0 fc0 sc0 ls4c ws1"> 2</div><div class="t m0 x3c h15 yc2 ff1 fs7 fc0 sc0 ls1 ws1">4</div><div class="t m0 x3d h2 yc1 ff1 fs0 fc0 sc0 ls4d ws1"> 2</div><div class="t m0 x3e h15 yc2 ff1 fs7 fc0 sc0 ls1 ws1">3</div><div class="t m0 x3f h2 yc1 ff1 fs0 fc0 sc0 ls4e ws1"> 2</div><div class="t m0 x40 h15 yc2 ff1 fs7 fc0 sc0 ls1 ws1">2</div><div class="t m0 x41 h2 yc1 ff1 fs0 fc0 sc0 ls4f ws1"> 2</div><div class="t m0 x42 h15 yc2 ff1 fs7 fc0 sc0 ls1 ws1">1</div><div class="t m0 x43 h2 yc1 ff1 fs0 fc0 sc0 ls50 ws1"> 2</div><div class="t m0 x1c h15 yc2 ff1 fs7 fc0 sc0 ls1 ws1">0</div><div class="t m0 x44 h2 yc1 ff1 fs0 fc0 sc0 ls51 ws8f"> MSB </div><div class="t m0 x1 h3 yc3 ff1 fs1 fc0 sc0 ls1 ws1"> </div><div class="t m0 x45 h16 yc4 ff5 fs8 fc0 sc0 ls52 ws90">TEMPERATURE <span class="_ _2a"> </span>DIGITAL OUTP<span class="_ _4"></span>UT (Binary) <span class="_ _2b"> </span>DIGITAL OUTP<span class="_ _4"></span>UT (Hex) </div><div class="t m0 x46 h17 yc5 ff1 fs8 fc0 sc0 ls53 ws91">+125°C 01111101 <span class="_ _2c"></span>00000000 <span class="_ _2d"> </span>7D00h </div><div class="t m0 x47 h17 yc6 ff1 fs8 fc0 sc0 ls54 ws92">+25.0625°C 00011001 <span class="_ _2e"></span>00010000 <span class="_ _2f"> </span>1910h </div><div class="t m0 x48 h17 yc7 ff1 fs8 fc0 sc0 ls54 ws93">+0.5°C 00000000 <span class="_ _30"></span>10000000 <span class="_ _2d"> </span>0080h </div><div class="t m0 x49 h17 yc8 ff1 fs8 fc0 sc0 ls55 ws94">0°C 00000000 <span class="_ _31"></span>00000000 <span class="_ _25"></span>0000h </div><div class="t m0 x4a h17 yc9 ff1 fs8 fc0 sc0 ls56 ws95">-0.5°C 11111111 <span class="_ _32"></span>10000000 <span class="_ _26"></span>FF80h </div><div class="t m0 x4b h17 yca ff1 fs8 fc0 sc0 ls55 ws96">-25.0625°<span class="_ _1"></span>C 11100110 <span class="_ _33"></span>11110000 <span class="_ _34"> </span>E6F0h </div><div class="t m0 x4c h17 ycb ff1 fs8 fc0 sc0 ls57 ws97">-55°C 11001001 <span class="_ _35"></span>00000000 <span class="_ _36"></span>C900h </div><div class="t m0 x1 h3 ycc ff1 fs1 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h4 ycd ff2 fs2 fc0 sc0 ls58 ws98">OPERATION-MEASURING BATTERY VOLTA<span class="_ _1"></span>GE </div><div class="t m0 x1 h3 yce ff1 fs1 fc0 sc0 ls11 ws99">The on-board analog-to-digital convert<span class="lsf ws9a">er (ADC) <span class="_ _4"></span>has 10 bits of resoluti<span class="ls13 ws9b">on <span class="_ _1"></span>and will perform a conversion </span></span></div><div class="t m0 x1 h3 ycf ff1 fs1 fc0 sc0 ls9 ws72">when the DS2438 receives a command protocol (Convert <span class="_ _4"></span><span class="ls37 ws9c">V) instructing it to<span class="_ _26"></span> do so. The result of this </span></div><div class="t m0 x1 h3 yd0 ff1 fs1 fc0 sc0 ls13 ws9d">measurement is placed in the 2-b<span class="_ _4"></span>y<span class="_ _26"></span>te Voltage Regi<span class="lsd ws9e">ster. The ran<span class="_ _4"></span>g<span class="_ _1"></span>e for the DS2438 ADC is 0 volt to </span></div><div class="t m0 x1 h3 yd1 ff1 fs1 fc0 sc0 ls22 ws9f">10 <span class="_ _26"></span>volt; this range is suitable f<span class="_ _1"></span>or NiCd or NiMH battery packs up to six cells, a<span class="_ _1"></span>nd for lithium ion batte<span class="_ _1"></span>ry </div><div class="t m0 x1 h3 yd2 ff1 fs1 fc0 sc0 ls9 wsa0">packs of two cells. The full-scale range of the ADC is<span class="ls5 wsa1"> scaled to 10.23 volt, resulting in a resolut<span class="_ _1"></span>ion of </span></div><div class="t m0 x1 h3 yd3 ff1 fs1 fc0 sc0 ls1 ws1">10 mV. </div><div class="t m0 x1 h14 yd4 ff6 fs1 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h3 yd5 ff1 fs1 fc0 sc0 ls13 wsa2">While the ADC has a range that extends down to 0 volt, <span class="lsf wsa3">it is important to note that the battery voltage can </span></div><div class="t m0 x1 h3 yd6 ff1 fs1 fc0 sc0 lsf wsa4">also be the supply voltage<span class="_ _1"></span> to the DS2438. As such, <span class="lse wsa5">the accurac<span class="_ _4"></span>y<span class="_ _1"></span> of the ADC begins to degrade below </span></div><div class="t m0 x1 h3 yd7 ff1 fs1 fc0 sc0 ls37 wsa6">battery voltages of 2.4 volt, and th<span class="lsf wsa7">e ability<span class="_ _26"></span> to make conversions is <span class="ls1e wsa8">limited by the operating voltage range </span></span></div><div class="t m0 x1 h3 yd8 ff1 fs1 fc0 sc0 ls4 ws3">of the DS2438. </div><div class="t m0 x1 h14 yd9 ff6 fs1 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h3 yda ff1 fs1 fc0 sc0 ls3c wsa9">Voltage is expressed in this register<span class="_ _1"></span> in scaled binary for<span class="_ _1"></span>mat, as outlined in Table 2. Note that while codes </div><div class="t m0 x1 h3 ydb ff1 fs1 fc0 sc0 ls1b wsaa">exist for values below 2.4 volt, accurac<span class="_ _4"></span>y<span class="_ _1"></span> of the <span class="ls37 ws8a">ADC and the limitation on the DS2438’s supply voltage </span></div><div class="t m0 x1 h3 ydc ff1 fs1 fc0 sc0 ls44 wsab">make it unlikely<span class="_ _26"></span> that these values would be used in<span class="_ _1"></span><span class="ls40 wsac"> actual practice. See “Mem<span class="_ _4"></span>ory<span class="_ _1"></span> Map” section <span class="_ _4"></span>for the </span></div><div class="t m0 x1 h3 ydd ff1 fs1 fc0 sc0 lsf wse">Voltage Register address location. </div></div><div class="pi" data-data='{"ctm":[1.568627,0.000000,0.000000,1.568627,0.000000,0.000000]}'></div></div>

<div id="pf5" class="pf w0 h0" data-page-no="5"><div class="pc pc5 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/622b818615da9b288b989923/bg5.jpg"><div class="t m0 x1d h2 y5f ff1 fs0 fc0 sc0 ls2d ws1">DS2438 </div><div class="t m0 x1e h2 y60 ff1 fs0 fc0 sc0 ls2e ws3c"> <span class="_ _e"> </span>5 of 29 </div><div class="t m0 x1 h13 y61 ff2 fs2 fc0 sc0 ls59 wsad">VOLTA<span class="_ _1"></span>GE REGISTER FOR<span class="_ _26"></span>M<span class="_ _4"></span>A<span class="_ _1"></span>T <span class="ff6 ls46 ws8c">Table 2</span><span class="ls1 ws1"> </span></div><div class="t m0 x1 h3 yaf ff1 fs1 fc0 sc0 ls1 ws1"> </div><div class="t m0 x4d h2 yde ff1 fs0 fc0 sc0 ls1 ws1">2</div><div class="t m0 x25 h15 ydf ff1 fs7 fc0 sc0 ls1 ws1">7</div><div class="t m0 x4e h2 yde ff1 fs0 fc0 sc0 ls4c ws1"> 2</div><div class="t m0 x23 h15 ydf ff1 fs7 fc0 sc0 ls1 ws1">6</div><div class="t m0 x39 h2 yde ff1 fs0 fc0 sc0 ls50 ws1"> 2</div><div class="t m0 x3a h15 ydf ff1 fs7 fc0 sc0 ls1 ws1">5</div><div class="t m0 x3b h2 yde ff1 fs0 fc0 sc0 ls50 ws1"> 2</div><div class="t m0 x33 h15 ydf ff1 fs7 fc0 sc0 ls1 ws1">4</div><div class="t m0 x3d h2 yde ff1 fs0 fc0 sc0 ls50 ws1"> 2</div><div class="t m0 x35 h15 ydf ff1 fs7 fc0 sc0 ls1 ws1">3</div><div class="t m0 x4f h2 yde ff1 fs0 fc0 sc0 ls5a ws1"> 2</div><div class="t m0 x40 h15 ydf ff1 fs7 fc0 sc0 ls1 ws1">2</div><div class="t m0 x41 h2 yde ff1 fs0 fc0 sc0 ls4e ws1"> 2</div><div class="t m0 x42 h15 ydf ff1 fs7 fc0 sc0 ls1 ws1">1</div><div class="t m0 x43 h2 yde ff1 fs0 fc0 sc0 ls50 ws1"> 2</div><div class="t m0 x1c h15 ydf ff1 fs7 fc0 sc0 ls1 ws1">0</div><div class="t m0 x44 h2 yde ff1 fs0 fc0 sc0 ls5b wsae"> LSB </div><div class="t m0 x1 h3 ye0 ff1 fs1 fc0 sc0 ls1 ws1"> MSb <span class="_ _37"> </span>(unit = 10 mV) <span class="_ _38"> </span>LSb </div><div class="t m0 x50 h2 ye1 ff1 fs0 fc0 sc0 ls2d wsaf">0 <span class="_ _4"></span>0 0 0 0 <span class="_ _39"> </span>0 <span class="_ _26"></span>2</div><div class="t m0 x51 h15 ye2 ff1 fs7 fc0 sc0 ls1 ws1">9</div><div class="t m0 x52 h2 ye1 ff1 fs0 fc0 sc0 ls5c ws1"> 2</div><div class="t m0 x1c h15 ye2 ff1 fs7 fc0 sc0 ls1 ws1">8</div><div class="t m0 x44 h2 ye1 ff1 fs0 fc0 sc0 ls51 ws8f"> MSB </div><div class="t m0 x1 h3 ye3 ff1 fs1 fc0 sc0 ls1 ws1"> </div><div class="t m0 x47 h16 ye4 ff5 fs8 fc0 sc0 ls5d ws1">BATTERY </div><div class="t m0 x47 h17 ye5 ff5 fs8 fc0 sc0 ls5e ws1">VOLTAGE<span class="ff1 ls1"> </span></div><div class="t m0 x53 h16 ye4 ff5 fs8 fc0 sc0 ls52 ws90">DIGITAL OUTP<span class="_ _4"></span>UT (Binary) <span class="_ _2b"> </span>DIGITAL OUTP<span class="_ _4"></span>UT (Hex) </div><div class="t m0 x4c h17 ye6 ff1 fs8 fc0 sc0 ls1 ws1">0.05V <span class="_ _3a"> </span>0000 0000 0000 0101 <span class="_ _3b"> </span>0005h </div><div class="t m0 x54 h17 ye7 ff1 fs8 fc0 sc0 ls56 wsb0">2.7V <span class="_ _3c"> </span>0000 0001 0000 1110 <span class="_ _3d"> </span>010Eh </div><div class="t m0 x54 h17 ye8 ff1 fs8 fc0 sc0 ls1 ws1">3.6V <span class="_ _3c"> </span>0000 0001 0110 1000 <span class="_ _3b"> </span>0168h </div><div class="t m0 x55 h17 ye9 ff1 fs8 fc0 sc0 ls56 wsb0">5V <span class="_ _3e"> </span>0000 0001 1111 0100 <span class="_ _3d"> </span>01F4h </div><div class="t m0 x54 h17 yea ff1 fs8 fc0 sc0 ls54 wsb1">7.2V <span class="_ _3c"> </span>0000 0010 1101 0000 <span class="_ _3f"> </span>02D0h </div><div class="t m0 x4c h17 yeb ff1 fs8 fc0 sc0 ls56 wsb0">9.99V <span class="_ _3a"> </span>0000 0011 1110 0111 <span class="_ _3d"> </span>03E7h </div><div class="t m0 x56 h17 yec ff1 fs8 fc0 sc0 ls55 wsb2">10V <span class="_ _40"> </span>0000 0011 1110 1000 <span class="_ _41"> </span>03E8H </div><div class="t m0 x1 h3 yed ff1 fs1 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h3 yee ff1 fs1 fc0 sc0 ls5 wsb3">For applications requiring a g<span class="_ _26"></span>en<span class="_ _4"></span>eral <span class="_ _1"></span>purpose voltage <span class="ls9 ws8">A/D converter, the DS2438 can b<span class="_ _4"></span>e configured s<span class="_ _4"></span>o that </span></div><div class="t m0 x1 h3 yef ff1 fs1 fc0 sc0 ls11 ws2a">the result of a Convert V command will place the scaled<span class="ls13 wsb4"> binar<span class="_ _4"></span>y<span class="_ _26"></span> rep<span class="_ _4"></span>r<span class="_ _1"></span>esentation of the voltage on the V</span></div><div class="t m0 x57 h5 yf0 ff1 fs3 fc0 sc0 ls5f ws1">AD</div><div class="t m0 x58 h15 yef ff1 fs7 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h3 yf1 ff1 fs1 fc0 sc0 ls1 wsb5">input (as opposed to the V</div><div class="t m0 x59 h5 yf2 ff1 fs3 fc0 sc0 ls34 ws1">DD</div><div class="t m0 x2f h3 yf1 ff1 fs7 fc0 sc0 ls1 ws1"> <span class="_ _42"> </span><span class="fs1 ls12 wsb6">input) into the Voltage Re<span class="_ _4"></span>g<span class="_ _26"></span>i<span class="_ _4"></span>ster in th<span class="ls13 wsb7">e same format described in Table 2. </span></span></div><div class="t m0 x1 h3 yf3 ff1 fs1 fc0 sc0 ls5 wsb8">Depending upon the state of the Status/Configura<span class="ls1e wsb9">tion Re<span class="_ _4"></span>g<span class="_ _26"></span>i<span class="_ _4"></span>ster, either (but not both) the V</span></div><div class="t m0 x5a h5 yf4 ff1 fs3 fc0 sc0 ls34 ws1">DD</div><div class="t m0 x5b h3 yf3 ff1 fs7 fc0 sc0 ls1 ws1"> <span class="_ _39"> </span><span class="fs1 ls60 wsba">or V</span></div><div class="t m0 x57 h5 yf4 ff1 fs3 fc0 sc0 ls5f ws1">AD</div><div class="t m0 x58 h15 yf3 ff1 fs7 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h3 yf5 ff1 fs1 fc0 sc0 ls5 ws5b">voltage will be stored in the Vo<span class="wsbb">ltage Register upon receipt of th<span class="ls13 wsbc">e Convert V command. Refer to the </span></span></div><div class="t m0 x1 h3 yf6 ff1 fs1 fc0 sc0 ls12 wsbd">description of the Status/Configur<span class="ls6 wsbe">ation Register in the Me<span class="_ _1"></span>mory Map section for details. If the<span class="_ _1"></span> V</span></div><div class="t m0 x5c h5 yf7 ff1 fs3 fc0 sc0 ls28 ws1">AD</div><div class="t m0 x5d h3 yf6 ff1 fs7 fc0 sc0 ls1 ws1"> <span class="_ _4"></span><span class="fs1 ls14">input </span></div><div class="t m0 x1 h3 yf8 ff1 fs1 fc0 sc0 lsd wsc">is used as the voltage input, the A/D will be accurate for 1.5V < V</div><div class="t m0 xc h5 yf9 ff1 fs3 fc0 sc0 ls5f ws1">AD</div><div class="t m0 x5e h3 yf8 ff1 fs7 fc0 sc0 ls1 ws1"> <span class="fs1 ls1f ws5f">< 2V</span></div><div class="t m0 x5f h5 yf9 ff1 fs3 fc0 sc0 ls28 ws1">DD</div><div class="t m0 x60 h3 yf8 ff1 fs7 fc0 sc0 ls61 ws1"> <span class="fs1 ls62 wsbf">over the ran<span class="_ _4"></span>ge 2.4V < V</span></div><div class="t m0 x61 h5 yf9 ff1 fs3 fc0 sc0 ls28 ws1">DD</div><div class="t m0 x62 h3 yf8 ff1 fs7 fc0 sc0 ls1 ws1"> <span class="fs1 ls63">< </span></div><div class="t m0 x1 h3 yfa ff1 fs1 fc0 sc0 lsd ws23">5.0V. This feature gives the user the ability to have a voltage A/D that m<span class="ls41 ws79">eets spec accuracy for inputs </span></div><div class="t m0 x1 h3 yfb ff1 fs1 fc0 sc0 ls62 wsc0">over the entire rang<span class="_ _4"></span>e of 1.5V < V</div><div class="t m0 x63 h5 yfc ff1 fs3 fc0 sc0 ls5f ws1">AD</div><div class="t m0 x31 h3 yfb ff1 fs7 fc0 sc0 ls1 ws1"> <span class="fs1 ls64 wsc1">< 10V for V</span></div><div class="t m0 x64 h5 yfc ff1 fs3 fc0 sc0 ls65 ws1">DD</div><div class="t m0 x65 h3 yfb ff1 fs7 fc0 sc0 ls1 ws1"> <span class="fs1 lse wsd">= 5.0V. </span></div><div class="t m0 x1 h3 yfd ff1 fs1 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h4 yfe ff2 fs2 fc0 sc0 ls66 wsc2">OPERATION - MEA<span class="_ _26"></span>SU<span class="_ _4"></span>RING BA<span class="_ _26"></span>T<span class="_ _4"></span>TERY CURRENT </div><div class="t m0 x1 h3 yff ff1 fs1 fc0 sc0 ls17 ws62">The DS2438 features an A/D converter <span class="lsd wsc3">that effectivel<span class="_ _4"></span>y<span class="_ _1"></span> measures the current flow into and out of the </span></div><div class="t m0 x1 h3 y100 ff1 fs1 fc0 sc0 ls67 wsc4">battery pac<span class="_ _1"></span>k by mea<span class="_ _1"></span>suring the voltage<span class="_ _1"></span> across a<span class="_ _1"></span>n extern<span class="ls8 wsc5">al sense resistor. It does so in the back<span class="_ _4"></span>g<span class="_ _26"></span>roun<span class="_ _4"></span>d at a </span></div><div class="t m0 x1 h3 y101 ff1 fs1 fc0 sc0 lsf wsbb">rate of 36.41 measurements/sec; thus, no command is required to initiate current flow measurements. </div><div class="t m0 x1 h3 y102 ff1 fs1 fc0 sc0 ls1b wsc6">However, the DS2438 will only perform current<span class="_ _4"></span> A/D meas<span class="ls4 wsc7">urements if the IAD bit is set to “1” in the </span></div><div class="t m0 x1 h3 y103 ff1 fs1 fc0 sc0 ls12 wsc8">Status/Configuration Register. The DS2438 measures cur<span class="_ _4"></span>r<span class="_ _1"></span>ent flow in and out of the b<span class="_ _4"></span>attery through the </div><div class="t m0 x1 h3 y104 ff1 fs1 fc0 sc0 ls1 ws1">V</div><div class="t m0 x66 h5 y105 ff1 fs3 fc0 sc0 ls68 ws1">SENS</div><div class="t m0 x22 h3 y106 ff1 fs1 fc0 sc0 ls10 wsc9"> pins; the voltage<span class="_ _1"></span> from the V</div><div class="t m0 x3a h5 y105 ff1 fs3 fc0 sc0 ls18 ws1">SENS+</div><div class="t m0 x67 h3 y106 ff1 fs1 fc0 sc0 lsb ws7a"> pin to th<span class="_ _1"></span>e V</div><div class="t m0 x68 h5 y105 ff1 fs3 fc0 sc0 ls18 ws1">SENS-</div><div class="t m0 x42 h3 y106 ff1 fs1 fc0 sc0 ls4 ws1e"> pin is considered to be the voltage across the </div><div class="t m0 x1 h3 y107 ff1 fs1 fc0 sc0 ls1b wsca">current sense resistor,<span class="_ _4"></span> R</div><div class="t m0 x27 h5 y108 ff1 fs3 fc0 sc0 ls68 ws1">SENS</div><div class="t m0 x69 h3 y107 ff1 fs1 fc0 sc0 ls17 wscb">. The V</div><div class="t m0 x6a h5 y108 ff1 fs3 fc0 sc0 ls18 ws1">SENS+</div><div class="t m0 x6b h3 y107 ff1 fs1 fc0 sc0 lsb ws7e"> terminal may be tied directly to the R</div><div class="t m0 x6c h5 y108 ff1 fs3 fc0 sc0 ls68 ws1">SENS</div><div class="t m0 x18 h3 y107 ff1 fs1 fc0 sc0 ls11 wscc"> resistor, howev<span class="_ _4"></span>er, for </div><div class="t m0 x1 h3 y109 ff1 fs1 fc0 sc0 ls1 ws1">V</div><div class="t m0 x66 h5 y10a ff1 fs3 fc0 sc0 ls18 ws1">SENS-</div><div class="t m0 x6d h3 y109 ff1 fs1 fc0 sc0 lsd wscd">, we recommend us<span class="_ _4"></span>e of an RC low pass f<span class="_ _1"></span>ilter between it and the <span class="_ _4"></span>GND end of R</div><div class="t m0 x6e h5 y10a ff1 fs3 fc0 sc0 ls68 ws1">SENS</div><div class="t m0 x6f h3 y109 ff1 fs1 fc0 sc0 ls62 wsce"> (see the <span class="_ _4"></span>block </div><div class="t m0 x1 h3 y10b ff1 fs1 fc0 sc0 ls13 wsb4">diagram in Figure 1). Us<span class="_ _4"></span>ing<span class="_ _26"></span> <span class="_ _4"></span>a 100 k<span class="ff8 ls1e ws1">W </span><span class="ls64 wscf">(min) resis<span class="_ _4"></span>tor (R</span></div><div class="t m0 x70 h5 y10c ff1 fs3 fc0 sc0 ls1 ws1">F</div><div class="t m0 x71 h3 y10b ff1 fs1 fc0 sc0 ls1b wsd0">) and a 0.1 <span class="_ _4"></span><span class="ff8 ls1 ws1">m</span><span class="ls69 wsd1">F tan<span class="_ _4"></span>talum capacito<span class="_ _4"></span>r (C</span></div><div class="t m0 x72 h5 y10c ff1 fs3 fc0 sc0 ls1 ws1">F</div><div class="t m0 x73 h3 y10b ff1 fs1 fc0 sc0 ls6a wsd2">), the filter </div><div class="t m0 x1 h3 y10d ff1 fs1 fc0 sc0 ls11 ws99">cutoff is approximatel<span class="_ _4"></span>y<span class="_ _26"></span> 15.9 Hz. The current A/D m<span class="ls41 wsd3">easures at a r<span class="_ _4"></span>ate of <span class="ls12 ws2d">36.41 times per second, or once </span></span></div><div class="t m0 x1 h3 y10e ff1 fs1 fc0 sc0 lsd wsd4">every 27.46 ms. This filter will capture the effect<span class="_ _4"></span> of mo<span class="ls4 wsd5">st current spikes, and will thus allow the current </span></div><div class="t m0 x1 h3 y10f ff1 fs1 fc0 sc0 ls62 wsc0">accumulators to a<span class="_ _4"></span>ccurately reflect t<span class="_ _4"></span>he total charge which has <span class="_ _4"></span>g<span class="_ _1"></span>one into or ou<span class="_ _4"></span>t of the battery. </div><div class="t m0 x1 h3 y110 ff1 fs1 fc0 sc0 ls1 ws1"> </div><div class="t m0 x1 h3 y111 ff1 fs1 fc0 sc0 ls3 wsd6">The voltage across current sense resistor R</div><div class="t m0 x74 h5 y112 ff1 fs3 fc0 sc0 ls68 ws1">SENS</div><div class="t m0 x36 h3 y111 ff1 fs1 fc0 sc0 ls7 wsd7"> is measured b<span class="_ _4"></span>y<span class="_ _26"></span> the A<span class="_ _4"></span>DC and the result is placed in<span class="_ _4"></span> the </div><div class="t m0 x1 h3 y113 ff1 fs1 fc0 sc0 ls6b wsd8">Current Reg<span class="_ _1"></span>ister in two’s complement fo<span class="_ _1"></span>rmat. The sign<span class="ls13 wsd9"> (S) of the result, indicating charge or dis<span class="_ _4"></span>charge, </span></div><div class="t m0 x1 h3 y114 ff1 fs1 fc0 sc0 ls6c wsda">resides in the most sig<span class="_ _26"></span>ni<span class="_ _4"></span>fic<span class="_ _1"></span>ant bit of the Curre<span class="_ _1"></span>nt Register<span class="_ _1"></span>, as shown in Table 3. See “Memory Map” in </div><div class="t m0 x1 h3 y115 ff1 fs1 fc0 sc0 lsd ws4b">Figure 7 for the Current Register <span class="_ _4"></span>address location. </div><div class="t m0 x1 h3 y116 ff1 fs1 fc0 sc0 ls1 ws1"> </div></div><div class="pi" data-data='{"ctm":[1.568627,0.000000,0.000000,1.568627,0.000000,0.000000]}'></div></div>