3.2Gbps SFP Transimpedance Amplifiers with RSSI

The MAX3724/MAX3725 transimpedance amplifiers provide a compact, low-power solution for communication up to 3.2Gbps. They feature 325nA input-referred noise at 2.1GHz bandwidth (BW) with 0.6pF input capacitance. The parts also have > 2mAP-P AC input overload.

Both parts operate from a single +3.3V supply and consume 93mW. The MAX3724/MAX3725 are in a compact 30-mil x 50-mil die and require no external compensation capacitor. A space-saving filter connection is provided for positive bias to the photodiode through an on-chip 580Ω resistor to VCC. These features allow easy assembly into a low-cost TO-46 or TO-56 header with a photodiode.

The MAX3724 and MAX3748A receiver chip set provides an RSSI output using a Maxim interface technique. The MAX3724 preamplifier, MAX3748A postamplifier, and the DS1858/DS1859 SFP controller meet all the SFF-8472 digital diagnostic requirements.

Applications

* Optimized for Small-Form-Factor Pluggable (SFP) Optical Receivers * Up to 3.2Gbps SFF/SFP Optical Receivers

* Wider Bandwidth than MAX3744/MAX3745

* RSSI Implementation in 4-Pin TO-46 Header (MAX3724 and MAX3748A)

* 8psP-P Deterministic Jitter for < 100µAP-P Input Current

* 325nARMS Input-Referred Noise at 2.1GHz Bandwidth

* 28mA Supply Current at +3.3V

* 2.5GHz Small-Signal Bandwidth

* 2.0mAP-P AC Overload

* Die Size: 30 mils x 50 mils (Identical to the MAX3744/MAX3745)