The MAX3747/MAX3747A multirate limiting amplifiers function as data quantizers for OC-3 through OC-48 synchronous optical network (SONET), Fibre-Channel, 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, currentmode logic (CML) output voltages with controlled edge speeds. The MAX3747 output voltage level is 500mVp-p and the MAX3747A output voltage is 800mVp-p. The MAX3747/MAX3747A limiting amplifiers feature a programmable loss-of-signal detect (LOS) and an optional disable function (DISABLE). Output disable can be used to implement squelch.