Low-Power, Compact, Multirate Limiting Amplifier for SFF/SFP Applications Functions as a Data Quantizer for SONET, Fibre-Channel and Gigabit Ethernet Optical Receivers
The MAX3746 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 selectable-level,
current-mode logic (CML) output voltages with controlled
edge speeds. A received-signal-strength indicator
(RSSI) is available when the MAX3746 is
DC-coupled to the MAX3744/MAX3724 SFP transimpedance
amplifier (TIA). A receiver consisting of the
MAX3744/MAX3724 and the MAX3746 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 MAX3746 and the MAX3744/MAX3724 allows for the implementation of all the small-form-factor SFF-8472 digital diagnostic specifications using a standard 4-pin TO-46 header.
The MAX3746 is pin-for-pin compatible with the
MAX3748A limiting amplifier and consumes 30% less
power. The MAX3746 is packaged in a 3mm x 3mm,
16-pin QFN package.