參數(shù)資料
型號: DS21354L
廠商: MAXIM INTEGRATED PRODUCTS INC
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): 107/126頁
文件大?。?/td> 1082K
代理商: DS21354L
DS21354/DS21554 3.3V/5V E1 Single-Chip Transceivers
81 of 124
15.1.
Receive Clock and Data Recovery
The DS21354/DS21554 contain a digital clock recovery system. See Figure 2-1 and Figure 15-1 for more
details. The device couples to the receive-E1-shielded twisted pair or coax via a 1:1 transformer. See
Table 15-3 for transformer details. The 2.048MHz clock attached at the MCLK pin is internally
multiplied by 16 via an internal PLL and fed to the clock recovery system. The clock recovery system
uses the clock from the PLL circuit to form a 16-times oversampler, which is used to recover the clock
and data. This oversampling technique offers outstanding jitter tolerance (Figure 15-3).
Normally, the clock that is output at the RCLKO pin is the recovered clock from the E1 AMI/HDB3
waveform presented at the RTIP and RRING inputs. When no AMI signal is present at RTIP and RRING,
a receive carrier loss (RCL) condition occurs, and the RCLKO is sourced from the clock applied at the
MCLK pin. If the jitter attenuator is either placed in the transmit path or is disabled, the RCLKO output
can exhibit slightly shorter high cycles of the clock, which is due to the highly oversampled digital clock
recovery circuitry. If the jitter attenuator is placed in the receive path (as is the case in most applications),
the jitter attenuator restores the RCLK to being close to 50% duty cycle. Please see the Receive AC
Timing Characteristics for more details.
15.2.
Transmit Waveshaping and Line Driving
The DS21354/DS21554 use a set of laser-trimmed delay lines along with a precision digital-to-analog
converter (DAC) to create the waveforms that are transmitted onto the E1 line. The waveforms meet the
ITU G.703 specifications (see Figure 15-5).
The user selects which waveform is to be generated by properly programming the L2/L1/L0 bits in the
Line Interface Control Register (LICR). The DS21354/DS21554 can set up in a number of various
configurations depending on the application. See tables below and Figure 15-5.
Table 15-1. Line Build-Out Select in LICR for the DS21554
L2
L1
L0
APPLICATION
TRANSFORMER
RETURN LOSS
(dB)*
RT (
W)
**
0
75
W normal
1:1.15 step-up
N.M.
0
1
120
W normal
1:1.15 step-up
N.M.
0
1
0
75
W with protection resistors
1:1.15 step-up
N.M.
8.2
0
1
120
W with protection resistors
1:1.15 step-up
N.M.
8.2
1
0
75
W with high return loss
1:1.15 step-up
21
27
1
0
75
W with high return loss
1:1.36 step-up
21
18
1
0
120
W with high return loss
1:1.36 step-up
21
27
* N.M. = Not Meaningful (return loss value too low for significance).
** Refer to Application Note 324 for details on E1 line interface design.
相關(guān)PDF資料
PDF描述
DS21354LN DATACOM, PCM TRANSCEIVER, PQFP100
DS21372TN SPECIALTY TELECOM CIRCUIT, PQFP32
DS21372T SPECIALTY TELECOM CIRCUIT, PQFP32
DS21372 SPECIALTY TELECOM CIRCUIT, PQFP32
DS2141AN DATACOM, FRAMER, PDIP40
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DS21354L+ 功能描述:網(wǎng)絡(luò)控制器與處理器 IC 3.3/5V E1 Single Chip 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
DS21354LB 功能描述:網(wǎng)絡(luò)控制器與處理器 IC 3.3/5V E1 Single Chip 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
DS21354LB+ 功能描述:網(wǎng)絡(luò)控制器與處理器 IC 3.3/5V E1 Single Chip 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
DS21354LC1 功能描述:網(wǎng)絡(luò)控制器與處理器 IC 3.3/5V E1 Single Chip 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
DS21354LC1+ 功能描述:網(wǎng)絡(luò)控制器與處理器 IC 3.3/5V E1 Single Chip 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