參數(shù)資料
型號: DS21554LN
廠商: DALLAS SEMICONDUCTOR
元件分類: Digital Transmission Interface
英文描述: DATACOM, PCM TRANSCEIVER, PQFP100
封裝: 14 X 14 MM, LQFP-100
文件頁數(shù): 90/117頁
文件大?。?/td> 698K
代理商: DS21554LN
DS21354 & DS21554
74 of 117
16.4 Protected Interfaces
In certain applications, such as connecting to the PSTN, it is required that the network interface be
protected from and resistant to certain electrical conditions. These conditions are divided into two
categories, surge and power line cross. A typical cause of surge is lightening strike. Power line cross
refers to accidental contact with high voltage power wiring. For protection against surges, additional
components and PCB layout considerations are required to reroute and dissipate this energy. In a surge
event, the network interface must not be damaged and continue to work after the event. In the event of a
power line contact, components such as fuses or PTCs that can “open” the circuit are required to prevent
the possibility of a fire caused by overheating the transformer. The circuit examples in this data sheet are
for “Secondary Over Voltage Protection” schemes for the line terminating equipment. Primary protection
is typically provided by the network service provide and is external to the equipment.
Figure 16-6 shows an example circuit for the 5 volt device and Figure 16-7 is an example for the 3.3 volt
device. In both examples, fuses are used to provide protection against power line cross. 470 ohm input
resistors on the receive pair, a transient suppresser and a diode bridge on the transmit pair provide surge
protection. Resistors R1 – R4 provide surge protection for the fuse. Careful selection of the transformer
will allow the use of a fuse that requires no additional surge protection such as the circuit shown in Figure
16-7. The circuit shown in Figure 16-7 is required for 3.3 volt operation since additional resistance in the
transmit pair cannot be tolerated. For more information on line interface design, consult the E1 Line
Interface Design Criteria and Secondary Over Voltage Protection application notes. These application
notes are available from Dallas Semiconductor’s web site.
PROTECTED INTERFACE EXAMPLE FOR THE DS21554 Figure 16-6
Note:
All capacitor values are in uf.
The 10uf capacitor on TVDD is of tantalum construction.
The 68uf cap is required to maintain VDD during a transient event.
RTIP
RRING
TTIP
TRING
Receive
Line
DS21554
S
C1
D1
D2
D3
D4
1:1
Fuse
Transmit
Line
Fuse
0.1
N:1
470
C2
R1
R2
R3
R4
Rt
Rterm
X1
X2
+5V
2.048MHz
MCLK
DVDD
DVSS
0.1
RVDD
RVSS
0.1
TVDD
TVSS
0.1
+5.0V
0.01
68
+
10
+
相關(guān)PDF資料
PDF描述
DS2155G DATACOM, FRAMER, PBGA100
DS21600SN PLL BASED CLOCK DRIVER, 2 TRUE OUTPUT(S), 0 INVERTED OUTPUT(S), PDSO16
DS21600N PLL BASED CLOCK DRIVER, 2 TRUE OUTPUT(S), 0 INVERTED OUTPUT(S), PDIP8
DS2155LN DATACOM, FRAMER, PQFP100
DS21602N PLL BASED CLOCK DRIVER, 2 TRUE OUTPUT(S), 0 INVERTED OUTPUT(S), PDIP8
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DS21554LN+ 功能描述:網(wǎng)絡(luò)控制器與處理器 IC 3.3/5V E1 Transceiver RoHS:否 制造商:Micrel 產(chǎn)品:Controller Area Network (CAN) 收發(fā)器數(shù)量: 數(shù)據(jù)速率: 電源電流(最大值):595 mA 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PBGA-400 封裝:Tray
DS2155DK 功能描述:網(wǎng)絡(luò)開發(fā)工具 RoHS:否 制造商:Rabbit Semiconductor 產(chǎn)品:Development Kits 類型:Ethernet to Wi-Fi Bridges 工具用于評估:RCM6600W 數(shù)據(jù)速率:20 Mbps, 40 Mbps 接口類型:802.11 b/g, Ethernet 工作電源電壓:3.3 V
DS2155G 功能描述:網(wǎng)絡(luò)控制器與處理器 IC T1/E1/J1 Transceiver RoHS:否 制造商:Micrel 產(chǎn)品:Controller Area Network (CAN) 收發(fā)器數(shù)量: 數(shù)據(jù)速率: 電源電流(最大值):595 mA 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PBGA-400 封裝:Tray
DS2155G/T&R 制造商:Maxim Integrated Products 功能描述:DS2155 T1/E1/J1 SCT 100P CSBGA T&R - Tape and Reel 制造商:Maxim Integrated Products 功能描述:IC LIU T1/E1/J1 SCT 100P CSBGA 制造商:Maxim Integrated Products 功能描述:Network Controller & Processor ICs T1/E1/J1 Transceiver