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Maxim - DS1878 SFP+ controller includes a digital LDD interface for communication with a laser driver/limiting amplifier.

20th January 2011

Maxim Integrated

ES Admin

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Datasheet

Maxim introduced the DS1878, a small form factor pluggable (SFP+) controller with a digital laser diode driver (LDD) interface. State machine based, the DS1878 eliminates the tedious software development process. It enables efficient implementation of the SFF-8472 specification and greatly reduces the time to market. Moreover, as the most reliable I2C controller available to optical transceiver designers, the DS1878 enhances the reliability of SFP+ optical transceiver modules.

The DS1878 controls and monitors all functions for SFF, SFP, and SFP+ optical modules and fully supports the SFF-8472 standard. It can be combined with a MAX3798 or MAX3799 SFP+ laser driver/limiting amplifier to provide an automatic power control (APC) loop, modulation current control, and eye safety functionality—the core feature set of SFP and SFP+ optical modules. The DS1878 also works with the MAX3945 limiting amplifier or the MAX3946 LDD to support 10GHz applications featuring distributed feedback (DFB) or electro-absorption-modulated (EML) lasers.

Laser modulation is controlled with a dedicated temperature-driven lookup table (LUT). Two additional 9-bit delta-sigma DAC outputs with 36-entry LUTs are provided. The DS1878 monitors six analog channels: temperature, Vcc, and MON1 to MON4; MON3 is a fully differential input.

The DS1878 is specified over the -40 degrees Celsius to +95 degrees Celsius temperature range. It uses 0.35micrometer technology to enable the high level of integration required for SFF-8472 implementation in a small 5mm x 5mm, 28-pin TQFN package with exposed pad. Pricing begins at $1.33 (1000-up, FOB USA).