This document provides information about the FT-901B-S-LC20 series 155Mbps Fast Ethernet SFP transceiver module. It operates at 1550nm for transmission and 1310nm for reception over single mode fiber with an LC connector and a reach of 20km. The module complies with relevant standards and has features such as hot pluggability and a TTL-level signal detect indicator. It provides optical-to-electrical conversion with differential inputs/outputs and includes a laser driver IC and post-amplification circuitry.

1. FT-901B-S-LC20 series
155Mpbs Fast Ethernet SFP Transceiver,
WDM-B, Single-Mode, TX1550/RX1310, LC 20km
Features:
▲SFP Multi-Source Agreement compliant
▲Compliant with SONET/SDH Standard
▲Compliant with Fast Ethernet standard
▲Compliant with IEEE802.3ah 100Base-BX
▲Compliant with ITU-T G.985 class S
▲Industry standard small form pluggable (SFP)
package
▲Simplex LC connector
▲Differential LVPECL inputs and outputs
▲Single power supply 3.3V
▲TTL signal detect indicator
▲Hot Pluggable
▲Class 1 laser product complies with EN 60825-1
▲RoHS compliant
Ordering Information:
Model Number Reach TX/RX Input/Out Signal Detect Temperature LD Type
FT-901B-S-LC20 20 km 1550/1310 AC/AC TTL 0°C ~ 70 °C 1550 FP
FT-901RB-S-LC20 20 km 1550/1310 AC/AC TTL -40°C ~ 85 °C 1550 FP
TEL: 886-2-2658-6893 FELIZ Technology Co., Ltd. ver. 1.1
sales@feliz.com.tw www.feliz.com.tw page: 1/4

2. FT-901B-S-LC20 series
155Mpbs Fast Ethernet SFP Transceiver,
WDM-B, Single-Mode, TX1550/RX1310, LC 20km
Absolute Maximum Ratings:
Parameter Symbol Min. Max. Units Note
Storage Temperature Ts -40 85 °C
Supply Voltage Vcc ## 4.0 V
Input Voltage V IN ## Vcc V
Output Current Io -- 50 mA
Operating Current I OP -- 400 mA
Recommended Operating Conditions:
Parameter Symbol Min. Max. Units Note
Operating Case 0 70 °C FT-901B-S-LC20
Tc
Temperature -40 85 °C FT-901RB-S-LC20
Supply Voltage Vcc 3.1 3.5 V
Supply Current I TX + I RX -- 200 mA
Transmitter Electro-optical Characteristics:
Vcc = 3.1 V to 3.5 V, T C = 0 °C to 70 °C (-40 °C to 85 °C)
Parameter Symbol Min. Type Max. Units Note
Output Optical Power
P out -14 -- -8 dBm Average
9/125 µm fiber
Extinction Ratio ER 8.2 -- -- dB
Center Wavelength λC 1480 1520 1580 nm
Spectral Width(RMS) λ -- -- 3 nm
Rise/Fall Time(10−90%) Tr, f -- 1 2 ns
Output Eye Compliant with Telcordia GR-253-CORE Issue 3 and ITU-T recommendation G-957
Max P out
P OFF -- -- -45 dBm
TX-DISABLE Asserted
Differential Input Voltage V DIFF 0.4 -- 2.0 V
TEL: 886-2-2658-6893 FELIZ Technology Co., Ltd. ver. 1.1
sales@feliz.com.tw www.feliz.com.tw page: 2/4

3. FT-901B-S-LC20 series
155Mpbs Fast Ethernet SFP Transceiver,
WDM-B, Single-Mode, TX1550/RX1310, LC 20km
Receiver Electro-optical Characteristics:
Vcc = 3.1 V to 3.5 V, T C = 0 °C to 70 °C (-40 °C to 85 °C)
Parameter Symbol Min. Type Max. Units Note
-10
Optical Input Power-max. P IN 0 -- -- dBm BER < 10
Optical Input Power-
min. P IN -- -- -32 dBm BER < 10
-10
(Sensitivity)
Operating Center Wavelength λC 1260 -- 1360 nm
Optical Return Loss ORL 14 -- -- dB λ=1260~1360nm
Optical isolation ISO -- -- -40 dB λ=1480~1600nm
Loss of Signal-Asserted PA -- -- -32 dBm
Loss of Signal-Deasserted PD -45 -- -- dBm
Differential Output Voltage V DIFF 0.5 -- 1.6 V
Data Output Rise, Fall
T r, f -- 1 2 ns
Time (10%−90%)
Receiver Loss of Signal
RX_LOS L 0 -- 0.5 V
Output Voltage-Low
Receiver Loss of Signal
RX_LOS H 2.4 -- V CC V
Output Voltage-High
Block Diagram of Transceiver:
TEL: 886-2-2658-6893 FELIZ Technology Co., Ltd. ver. 1.1
sales@feliz.com.tw www.feliz.com.tw page: 3/4

4. FT-901B-S-LC20 series
155Mpbs Fast Ethernet SFP Transceiver,
WDM-B, Single-Mode, TX1550/RX1310, LC 20km
Transmitter and Receiver Optical Sub-assembly Section
A 1550 nm InGaAsP laser and an InGaAs PIN photodiode integrate with an WDM filter to form a
bi-directional single fiber optical subassembly (OSA). The laser of OSA is driven by a LD driver IC which
converts differential input LVPECL logic signals into an analog laser driving current. And, The photodiode
of OSA is connected to a circuit providing post-amplification quantization, and optical signal detection.
TX_DISABLE
The TX_DISABLE signal is high (TTL logic “1”) to turn off the laser output.
Receive Loss (RX_LOS)
The RX_LOS is high (logic “1”) when there is no incoming light from the companion transceiver. This signal
is normally used by the system for the diagnostic purpose. The signal is operated in TTL level.
Dimensions:
Note: All information contained in this document is subject to change without notice.
TEL: 886-2-2658-6893 FELIZ Technology Co., Ltd. ver. 1.1
sales@feliz.com.tw www.feliz.com.tw page: 4/4