增加灵活性Microwire使用多种EEPROM封装

Formanyyears,the8-leadSOICpackagehasbeen

themostpopularpackageforserialEEPROMs,but

nowsmallerpackagesarebecomingmoreandmore

commonplace.Thisoffersanumberofbenefits;the

reductionsinfootprintsizeandcomponentheightare

someofthemoreobviousones.Smallerpackagesalso

generallyofferacostadvantageovertheirlarger

counterparts.

Currently,theSOT-23packageisoneofthesmallest

packagesavailableforserialEEPROMs,anditspopu-

larityhasbeengrowingsignificantly.However,while

theSOICisanindustry-standardpackageavailable

fromallmajorEEPROMvendors,theSOT-23package

isstillrelativelynew,especiallyinlargermemoryden-

sities.Whenanew,smallerpackageisfirstreleasedby

avendor,thereisalwaysaninherentlagbeforethe

packagebecomesavailablefromallvendors.For

example,Microchipwasthefirstvendortooffer32-and

64-KbitI

2

C™serialEEPROMsina5-leadSOT-23

packageanditwilltaketimebeforeothervendorsoffer

similardevices.

SystemdesignerscanusetheSOT-23packageand

enjoytheassociatedbenefits,ortheycanmaintaina

broadlistofpossiblevendors.Now,bycombining

footprints,bothcanbedoneatthesametime.AN1420AddingFlexibilitybyUsingMultipleFootprintsforMicrowireSerialEEPROMsThisideacanalsobeappliedtoother8-leadpackages,Author:ChrisParrissuchastheTSSOPandMSOP,iftheapplicationMicrochipTechnologyInc.allowsforasmallamountofextraboardspacetobeused.INTRODUCTIONFIGURE1:COMBINED6-LEADSOT-23Formanyyears,the8-leadSOICpackagehasbeen