PX5420

The growing use of serial optical modules in datacenter LAN and SAN infrastructures have created a need for multi gigabit optical modules. The introduction of 4 Gb/s Fiber Channel standard for SANs is leading the data rate requirements for current 1 Gb/s and 2 Gb/s optical modules while demanding full backward compatibility. The Zarlink PX5420 multi-rate TIA/LA optical receiver provides the performance and feature set required by competitive SFF and SFP optical modules.

The Zarlink PX5420 optical receiver is a single channel TIA/LA optical receiver designed for various applications to 4.25 Gb/s. It consists of a transimpedance amplifier (TIA) and an AC-coupled differential limiting amplifier (LA).

The transimpedance amplifier PX5420 achieves a nominal bandwidth of 3 GHz over a wide range of photodiode input capacitance. A photodiode bias current monitor allows for a simple alignment procedure.

The transimpedance amplifier PX5420 is AC-coupled internally to a high-gain, high-bandwidth, limiting amplifier. The limiting amplifier provides a differential back-terminated current-mode logic (CML) output that can be used to drive a 4.25 Gb/s intra module post amplifier or directly drive to the edge of the module.

Full diagnostics are delivered through loss of signal, squelch, and received signal strength indicator circuits.