Tag Archives: QSFP+ modules

The Introduction Of 40G QSFP+ AOC

The 40G QSFP+ AOC (40G QSFP+ AOC) is a parallel 40Gbps Quad Small Form Factor Pluggable (QSFP+) Active Optical Cable, which supplies higher port density and total system cost. The QSFP+ optical modules provide four full-duplex independent transmit and receive channels, each are able of 10Gbps operation 40Gbps aggregate bandwidth of at least 100m long multimode fibre.

The 40G QSFP+ AOC is according to QSFP+ Multi-Source Agreement(MSA) design and shape, optical/electrical connections and digital diagnostic interface. It is designed to meet the most demanding external operating conditions including temperature, humidity and EMI interference. This module supplies a quite high functionality and feature integration, through a two-wire serial interface to reach.

40G QSFP+ AOC Functional Description

The TF-QQxxx-N00 converts parallel electrical input signals using a laser driver and a Vertical Cavity Surface Emitting Laser (VCSEL) array into parallel optical output signals. The transmitter module accepts electrical input signals which can be voltage suitable for Common Mode Logic (CML) levels. All input data signals are differential and therefore are internally terminated. The receiver module converts parallel optical input signals using a receiver and a photo detector array into parallel electrical output signals. The receiver module outputs electrical signals, which are voltage suitable for Common Mode Logic (CML) levels. All data signals are differential and support a data rates as much as 10 Gbps per channel.

A single+3.3V power is needed to power up the module. Both power source pins VccTx and VccRx are internally connected and will be used concurrently. As per MSA specifications the module offers 7 low speed hardware control pins (including the 2-wire serial interface): ModSelL, SCL, SDA, ResetL, LPMode, ModPrsL and IntL.

Module Select (ModSelL) is an input pin. When held low by the host, the module responds to 2-wire serial communication commands. The ModSelL allows the use of multiple QSFP+ modules on a single 2-wire interface bus ¨C individual ModSelL lines per QSFP+ module can be used.

Serial Clock (SCL) and Serial Data (SDA) are needed for the 2-wire serial bus communication interface and let the host to connect to the QSFP+ memory map.

The ResetL pin to produce a complete module reset, the return capsule back to the default state , when within the ResetL pin low hold time is longer than the minimum pulse length . Master reset should be performed bit desperate state until reset interrupt instructions to finish the module .

Low Power Mode (LPMode) pin can be used to set the maximum power consumption for the module so that you can protect hosts that aren’t capable of cooling higher power modules, should such modules be accidentally inserted.

Module Present (ModPrsL) is a signal local to the host board which, even without the a module, is generally pulled up to the host Vcc. When a module is inserted in to the connector, it completes the path to ground though a resistor on the host board and asserts the signal. ModPrsL then indicates a module happens by setting ModPrsL to a “Low” state.

Interrupt (IntL) is an output pin. When “Low”, it indicates a probable module operational fault or a status critical to the host system. The host identifies the origin of the interrupt with all the 2-wire serial interface. The IntL pin can be an open collector output and should be pulled to the Host Vcc voltage on the Host board.

40G QSFP+ Active Optical Cable (AOC) is a high performance, low power consumption integrated cable for short-range multi-lane data communication and interconnect applications, supporting 40G Ethernet, fibre channel and PCIE. It is compliant using the QSFP+ MSA and IEEE P802.3ba 40GBASE-SR4. It has been designed to meet the harshest external operating conditions including temperature, humidity and EMI interference. FS.COM QSFP+ Cables can be found in various lengths along with other options.