MAX3746 Datasheet, PDF (1/12 Pages) Maxim Integrated Products – Low-Power, 622Mbps to 3.2Gbps

19-3386; Rev 0; 8/04
Low-Power, 622Mbps to 3.2Gbps
Limiting Amplifier
General Description
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 con-
trolled edge speeds. A received-signal-strength indica-
tor (RSSI) is available when the MAX3746 is
DC-coupled to the MAX3744/MAX3724 SFP transim-
pedance 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 dis-
able 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.
Applications
Gigabit Ethernet SFF/SFP Transceiver Modules
Fibre-Channel SFF/SFP Transceiver Modules
Multirate OC-12 to OC48-FEC SFF/SFP
Transceiver Modules
Features
♦ SFP Reference Design Available
♦ Low 115mW Power Consumption
♦ 16-Pin QFN Package with 3mm x 3mm Footprint
♦ 70ps Rise and Fall Time
♦ Loss-of-Signal with Programmable Threshold
♦ RSSI Interface (with MAX3744/MAX3724 TIA)
♦ Output Disable
♦ Polarity Select
♦ 8.4ps_P-P Deterministic Jitter (3.2Gbps)
♦ Improved EMI Performance
♦ Selectable CML Output levels
♦ Pin Compatible with MAX3748A
Ordering Information
PART
TEMP RANGE PIN-PACKAGE PKG CODE
MAX3746ETE -40°C to +85°C 16 QFN
T1633F-3
Pin Configuration appears at end of data sheet.
Typical Operating Circuits continued at end of data sheet.
Typical Operating Circuits
4-PIN TO HEADER
MAX3744 TIA
DS1859
3-INPUT DIAGNOSTIC
MONITOR
R1
3kΩ
SFP OPTICAL RECEIVER
OUTPOL
VCC
IN+
IN-
MAX3746
RSSI TH
GND
RTH = 14kΩ
C1
0.1µF
SUPPLY FILTER
HOST BOARD
HOST FILTER
VCC_RX
OUT+
OUT-
0.1µF
0.1µF
50Ω
SERDES
50Ω
DISABLE LOS
4.7kΩ TO 10kΩ
2.97V TO 3.6V
LOS
________________________________________________________________ Maxim Integrated Products 1
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