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 75Ω coax or 120Ω twisted wire pair line. Also a change in the termination resistor is required. A single set of resistors can be utilized in both situations by using the circuit shown in Figure 1. The dotted lines indicate jumper positions for selecting 75Ω or 120Ω operation. Figure 1. E1 interface. Table 1. Line Interface Control Register Settings Line Type L2 L1 L0 75Ω 0 1 0 120Ω 0 1 0 Notes: Transformers shown are available from Pulse. Resistors shown are within 1" of best value. 相关型号   APP 322: May 08, 2001 DS2154 增强型E1单芯片收发器 完整的数据资料 (PDF, 1MB) 免费样品 自动更新 需要自动接收最新发布的应用笔记吗？请订阅EE-Mail™ (English only)。 我们期待您的反馈！ 喜欢？不喜欢？有待改善？或为我们提供建议？请与我们联系 — 我们将根据您的意见或建议改善我们的工作。 网页评价或提供建议   下载，PDF格式 (25kB)  AN322, AN 322, APP322, Appnote322, Appnote 322