Optical transceivers

Analog Devices’ new SFP (small form factor pluggable) optical transceiver chipset and reference design supports both gigabit Ethernet and Fibre Channel data rates up to 4.25 Gbit/sec in SAN (storage area network) equipment.

The 1x/2x/4x SFP chipset meets the requirements of the Fibre Channel MSA (Multisource Agreement) specifications and is optimized for SFF-8472 digital diagnostics.

The SFP chipset includes four Analog Devices’ products designed to work seamlessly together.

On the receive chain, the ADN2882, a 4.25 Gbit/sec TIA (transimpedance amplifier), has a sensitivity of -22 dBm, while dissipating only 75 mW of power.

The ADN2892, a 4.25 Gbit/sec limiting amplifier, features selectable bandwidth for operation at the 1x and 2x Fibre Channel rates (1.063 Gbit/sec and 2.125 Gbit/sec) and the gigabit Ethernet rate (1.25 Gbit/sec) ensuring backwards compatibility to 1x and 2x Fibre Channel modules, while dissipating 160 mW of power.

On the transmit side, Analog Devices offers a choice of laser diode drivers. The ADN2871 single-loop LDD supports VCSEL (vertical-cavity surface-emitting laser) DFB (distributed feedback) and FP (Fabry-Perot) lasers, and provides over 45% eye margin to the 4x Fibre Channel mask.

The ADN2870 dual-loop laser diode driver automatically controls DFB and FP lasers over temperature and compensates for laser aging, thus reducing or eliminating the need for expensive temperature calibration.

Use of Analog Device’s ADuC7020 precision microcontroller allows the module function to be set in software or control more complicated and higher performance modules. On a single-chip, the microcontroller integrates a 32-bit RISC core with precision data conversion technology that supports up to 16 channels of 12-bit analog-to-digital conversion and up to four 12-bit digital-to-analog converters.

The 1x/2x/4x multi-rate reference design includes an SFP board and the optics to enable immediate evaluation. In addition, the reference design includes a host board, I2C support, Gerber files, object and source code for the microcontroller, a graphical user interface and technical documentation.

The ADN2882 TIA, ADN2892 limiting amplifier and ADN2870 dual-loop laser driver are available in production quantities now. Samples of the ADN2882 TIA are available in either die form or in a receive optical sub-assembly (ROSA). The ADN2871 single-loop laser driver will sample in February of 2005. The ADuC7020 precision microcontroller is sampling now and will be available in production quantities in July 2005.

The chipset will sell in high volume for $3.90.

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