GAOTek Copper SFP Transceiver 1.25Gb (1000BASE-T, Link )

This 1.25 Gbps 1000BASE-T Copper SFP transceiver is used to span up to 1.2 Miles (2 Km) transmission distance


This 1.25 Gbps Copper SFP transceiver is used to span up to 1.2 Miles (2 Km) over the unshielded twisted pair of Cat 5 Cable. This Copper Small Form-Factor Pluggable (Copper SFP) is compatible with the Gigabit Ethernet Standards specified in IEEE STD 802.3, 1000BASE-X auto-negotiation and ROHS Standards.

Key Features

  • Up to 1.25 Gb/s bi-directional data links
  • 25 Gigabit Ethernet over Cat 5 cable
  • 10/100/1000 BASE-T operation in host systems with SGMII interface
  • Compact RJ-45 connector assembly
  • Hot-pluggable SFP footprint
  • Low power dissipation(1.05W typical)
  • Fully metal enclosure, for lower EMI
  • RoHS compliant and lead-free
  • Single +3.3V power supply
  • Case operating temperature range from

Commercial: 32° F to 158° F (0°C to +70°C)

Extended: 14°F to 176°F (-10°C to +80°C)

Industrial: -40°F to 185°F (-40°C to +85°C)

Technical Specifications

Protocol 2 Wire Serial Communication
Standard IEEE Std 802.3

1000BASE-X auto-negotiation


Working Range Up to  1.2 Miles (2Km)
Data rate 1.25 Gb/s
Line Frequency 125 MHz
Cable Length 100 m
Supply Current 375 mA
Dimensions 2.28in*0.52in*0.5 in

(L  58mm*W 13.4mm*H 15mm)

Storage Temperature -40°F to 185°F (-40°C to 85°C)
Case Operating Temperature Commercial: 32° F to 158° F(0°C to +70°C)

Extended: 14°F to 176°F(-10°C to +80°C)

Industrial: -40°F to 185°F (-40°C to +85°C)

PIN Descriptions:


  1. Circuit ground is connected to chassis ground
  2. Should be pulled up with 4.7k – 10k Ohms on host board to a voltage between 2.0 V and 3.6 V. MOD_DEF (0) pulls line low to indicate module is plugged in.
  3. LVTTL compatible with a maximum voltage of 2.5V.

General Specifications


  1. Clock tolerance is +/- 50 ppm
  2. By default, the GAO-CUSFP-103 is a full duplex device in preferred master mode
  3. Automatic crossover detection is enabled. External crossover cable is not required.
  4. GAO-CUSFP-104 does not support SGMII .With a SERDES the module will operate at 1000BASE-T only.

3.3 Electrical Power Interface:

The GAO-CUSFP-104 has an input voltage range of 3.3 V +/- 5%. The 4V maximum voltage is not allowed for continuous operation.

Note (1): Power consumption and surge current are higher than the specified values in the SFP MSA.

Low Speed Signals

MOD_DEF (1) (SCL) and MOD_DEF (2) (SDA) are open drain CMOS signals (see  “Serial Communication Protocol”). Both MOD_DEF (1) and MOD_DEF (2) must be pulled up to host_Vcc.

Serial Communication Protocol

GAO-CUSFP-104 supports the 2-wire serial communication protocol outlined in the SFP MSA. It uses an Atmel AT24C02B 256 byte EEPROM with an address of A0h.

High Speed Electrical Interface

All high-speed signals are AC-coupled internally.

Mechanical Specifications

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