SFP‐PX20 GEPON OLT SFP Transceiver 1.25Gbps, 1000BASE-PX20

WDS5441H-C(H)3AL

 GEPON OLT SFP Transceiver, 1000BASE-PX20+, for Wodaplug GEPON OLTs

General Description 

WDS5441H-C(H)3AL is a high performance transceiver  module  for  single  fiber communications  using  a  1490nm continuous-mode transmitter and a 1310nm burst-mode receiver. It is designed to meet CTC 3.0 and IEEE802.3ah -2004 1000BASE- PX20+ applications. Symetric datatransfer with 1,25Gbps speed upstream and 1,25Gbps downstream for up to 20km distance.

The transmitter has automatic power control (APC) function and temperature compensation circuitry to ensure stable optical power output and extinction ratio over all operating temperature range. The transmitter meets Class 1 eye safety per IEC825 and CDRH standards.

The receiver has a hermetically packaged APD-TIA (trans-impedance amplifier) pre-amplifier and a limiting amplifier with LVPECL compatible differential outputs. It features a burst-mode Loss of signal (LOS) output which is LVTTL compatible. The receiver offers bust-mode RSSI outputs, which is I2C

accessible digitized data stored in the internal flash memory.

The module provides digital diagnostic information of its operating conditions and status, including transmitting power, laser bias current, module temperature, supply voltage, and burst-mode receiving power. Calibration and alarm/warning threshold data are written and stored in the internal memory (EEPROM). The memory map is compatible with SFF-8472.

Features

z  Single fiber bi-directional data links application with 1.25Gbps upstream and 1.25Gbps downstream. z 1490nm continuous mode DFB transmitter. 

z  1310nm burst mode APD-TIA receiver. z High power 1550nm video signal rejection . z 0 to 70°C and -40 to 85°C operating case temperature. z SFP package with SC/UPC receptacle. z Single +3.3V power supply.  z LVPECL interface logic level for data input and output. z LVTTL transmitter disable control

z  LVTTL transmitter laser failure alarm z LVTTL receiver Loss of Signal (LOS) indication z LVTTL RSSI Trigger control z Low EMI and excellent ESD protection z ClassⅠlaser safety standard IEC-60825 compliant z Complies with RoHS-6

Applications

z  Gigabit Ethernet Passive Optical Networks(GEPON) – OLT side 

Standard

z Compliant with SFF MSA - 2000 

z Compliant with SFF-8472 Rev.11.0

z Compliant with IEEE 802.3ah-2004  

z Compliant with FCC 47 CFR Part 15, Class B

z Compliant with FDA 21 CFR 1040.10 and 1040.11, ClassⅠ

z Complies with China Telecom EPON equipment technology requirement V3.0

Absolute Maximum Ratings

Recommended Operating Conditions

Transmitter Optical and Electrical Characteristics 

Note 1: Launched into 9/125um Single Mode Fiber.

Note 2: Measured with PRBS 2⁷-1 test pattern @1.25Gbit/s.

Note 3: Measured with the Bessel-Thompson filter OFF.

Note 4: Maximum sensitivity penalty due to transmitter and dispersion effect through 20km of SMF optical fiber.

Note 5: Compatible with LVPECL input, AC coupled internally. 

Note 6: Transmitter enable and disable timing

Receiver Optical and Electrical Characteristics 

Note 1: Measured with a PRBS 2⁷-1 test pattern @1.25Gbit/s and ER=10dB, BER =10^-12.

Note 2: Input optical power level difference of adjacent burst packets. 

Note 3: Low level indicates that burst packet is detected by the receiver. 

Note 4: LVPECL output, DC coupled internally, guaranteed in the full range of input optical power (-6dBm

to -30dBm) 

Note 5: RSSI DDM accuracy is better than +/-2dB (25℃) or +/-3dB (0℃~70℃) for input power levels between -6 to -30 dBm. Measured with 1310nm, 1.25Gbps PRBS27-1 burst-mode optical input, ER=10dB, 50%duty cycle. 

LOS Timing characteristics

The Timing characteristics for RSSI 

Figure 3  RSSI vs Trigger timing 

Digital Diagnostic Monitor Accuracy

Pin Description

Note: 

1. TX Fault is an open collector/drain output, which should be pulled up with a 4.7K–10KΩ resistor on the host board. Pull up voltage between 2.0V to VccT+0.3V or VccR+0.3V. High output indicates a laser fault of some kinds. Low indicates normal operation. In the low state, the output voltage will be below 0.8V.
2. TX disable is an input that is used to control the transmitter power output. It is pulled up within the module with a 4.7–10 KΩ resistor. Its states are: Low (0 – 0.8V): Transmitter on; (>0.8, < 2.0V):

Undefined; High (2.0 – Vcc): Transmitter Disabled Open: Transmitter Disabled

1. These pins should be pulled up with a 4.7K –10KΩ resistor on the host board. The pull-up voltage

shall be VccT or VccR. Mod-Def 0 is grounded by the module to indicate that the module is present.

1. RSSI TRIG is a LVTTL input. Assert high after 500ns delay time of the beginning of the monitored burst package,at least 500ns in duration.
2. LOS (Loss of Signal) is an open collector/drain output, which should be pulled up with a 4.7K – 10KΩ resistor to VccT +0.3V or VccR+0.3V. Low level indicates that burst packet is detected by the

receiver.  

1. RD-/+: These are the differential receiver outputs. They are DC coupled 100Ω differential line

which should be terminated with 100Ω (differential) at the user SER.DES.

1. VccR and VccT are the receiver and transmitter power supplies. They are defined as 3.3V ±5% at the SFP connector pin. Maximum supply current is 400mA. Recommended host board power supply

filtering is shown interface circuit. Inductors with DC resistance of less than 1Ω, in order to insure the voltage at the SFP input pin with 3.3V. When the recommended supply filtering network is used, hot plugging of the SFP transceiver module will result in an inrush current of no more than 30 mA greater than the steady state value. VccR and VccT may be internally connected within the SFP transceiver

module.

1. TD-/+: These are the differential transmitter inputs. They are AC-coupled, differential lines with100Ω differential termination inside the module. The AC coupling is done inside the module and is

thus not required on the host board.