The MAX3747/MAX3747A/MAX3747B multirate limiting amplifiers function as data quantizers for OC-3 through OC-48 synchronous optical network (SONET), FibreChannel, and Gigabit Ethernet optical receivers. They are pin-for-pin compatible with the SY88993V from Micrel Semiconductor, Inc. The amplifiers accept a wide range of input voltages and provide constant-level, current-mode logic (CML) output voltages with controlled edge speeds. The MAX3747 output voltage level is 500mVP-P and the MAX3747A/MAX3747B output voltages are 800mVP-P. The MAX3747B has enhanced LOS operation under overload conditions. The MAX3747/MAX3747A/MAX3747B limiting amplifiers feature a programmable loss-of-signal detect (LOS) and an optional disable function (DISABLE) that can be combined to implement squelch.