The MAX3748/MAX3748A multirate limiting amplifier functions as a data quantizer for SONET, Fibre Channel, and Gigabit Ethernet optical receivers. The amplifier accepts a wide range of input voltages and provides constantlevel current-mode logic (CML) output voltages with controlled edge speeds. A received-signal-strength indicator (RSSI) is available when the MAX3748/MAX3748A is combined with the MAX3744 SFP transimpedance amplifier (TIA). A receiver consisting of the MAX3744 and the MAX3748/ MAX3748A can provide up to 19dB RSSI dynamic range. Additional features include a programmable loss-of-signal (LOS) detect, an optional disable function (DISABLE), and an output signal polarity reversal (OUTPOL). Output disable can be used to implement squelch. The combination of the MAX3748/MAX3748A and the MAX3744 allows for the implementation of all the smallform-factor SFF-8472 digital diagnostic specifications using a standard 4-pin TO-46 header. The MAX3748/ MAX3748A is packaged in a 3mm 3mm 16-pin thin QFN package with an exposed pad.