DS2153 ， DS2154可选择120和75Ω E1接口

摘要：二次过电压保护或高回报的损失配置E1线路接口时，DS2153或DS2154单芯片收发器（SCT）和变压器之间可以选择不同的电阻值。

Maxim>AppNotes>COMMUNICATIONSCIRCUITSTELECOMKeywords:singlechiptransceiver,E1line,resistors,transformersinglechiptransceivers,SCTs,transformersMay08,2001APPLICATIONNOTE322DS2153,DS2154Selectable120and75E1InterfaceAbstract:DifferentvaluesofresistorcanbeselectedbetweenDS2153orDS2154singlechiptransceiver(SCT)andthetransformerwheninterfacingtotheE1linewithsecondaryovervoltageprotectionorinahighreturnlossconfiguration.WheninterfacingtotheE1linewithSecondaryOverVoltageprotectionorinahighreturnlossconfiguration,resistorsareaddedbetweentheDS2153outputsandthetransformer.Normallytheresistorsareofdifferentvaluesdependingonwhethertheinterfaceisdrivinga75coaxor120twiste