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 > App Notes > COMMUNICATIONS CIRCUITS TELECOM Keywords: single chip transceiver, E1 line, resistors, transformersingle chip transceivers, SCTs, transformers May 08, 2001 APPLICATION NOTE 322 DS2153, DS2154 Selectable 120 and 75 E1 Interface Abstract: Different values of resistor can be selected between DS2153 or DS2154 single chip transceiver (SCT) and the transformer when interfacing to the E1 line with secondary overvoltage protection or in a high return loss configuration. When interfacing to the E1 line with Secondary Over Voltage protection or in a high return loss configuration, resistors are added between the DS2153 outputs and the transformer. Normally the resistors are of different values depending on whether the interface is driving a 75 coax or 120 twiste……