3.3 V, 3.2 Gbps Limiting Amplifier

The ADN2891 is a 3.2 Gbps limiting amplifier with integrated loss-of-signal (LOS) detection circuitry and a received signal strength indicator (RSSI). This part is optimized for SONET, Gigabit Ethernet (GbE), and Fibre Channel optoelectronic conversion applications. The ADN2891 has a differential input sensitivity of 4 mV p-p and accepts up to a 2.0 V p-p differential input overload voltage. The ADN2891 supports current mode logic (CML) outputs with controlled rise and fall times.

By monitoring the bias current through a photodiode, the on-chip RSSI detector measures the average power received with 2% typical linearity over the entire valid input range of the photodiode. The on-chip RSSI detector facilitates SFF-8472-compliant optical transceivers by eliminating the need for external RSSI detector circuitry.

Additional features include a programmable loss-of-signal (LOS) detector and output squelch.

The ADN2891 is available in a 3 mm × 3 mm, 16-lead LFCSP.

Applications

* SFP/SFF/GBIC optical transceivers

* OC-3/OC-12/OC-48, GbE, Fibre Channel (FC) receivers

* 10GBASE-LX4 transceivers

* WDM transponders

* Input sensitivity: 4 mV p-p

* 80 ps rise/fall times

* CML outputs: 700 mV p-p differential

* Programmable LOS detector: 3.5 mV to 35 mV

* Rx signal strength indicator (RSSI)

* SFF-8472-compliant average power measurement

* Single-supply operation: 3.3 V

* Low power dissipation: 145 mW

* Available in space-saving 3 mm × 3 mm, 16-lead LFCSP

* Extended temperature range: −40°C to +95°C

* SFP reference design available