MAX3748 Datasheet, PDF (1/11 Pages) Maxim Integrated Products – Compact 155Mbps to 3.2Gbps Limiting Amplifier

19-2717; Rev 1; 7/03
EVAALVUAAILTAIOBNLEKIT
Compact 155Mbps to 3.2Gbps
Limiting Amplifier
General Description
The MAX3748/MAX3748A multirate limiting amplifier func-
tions as a data quantizer for SONET, Fibre Channel, and
Gigabit Ethernet optical receivers. The amplifier accepts
a wide range of input voltages and provides constant-
level current-mode logic (CML) output voltages with con-
trolled 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 small-
form-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 QFN
package with an exposed pad.
*Future product—contact factory for availability.
Applications
Gigabit Ethernet SFF/SFP Transceiver Modules
Fibre Channel SFF/SFP Transceiver Modules
Multirate OC-3 to OC-48-FEC SFF/SFP
Transceiver Modules
4-PIN TO HEADER
MAX3744 TIA*
DS1858
3-INPUT DIAGNOSTIC
MONITOR
R1
3kΩ
SFP OPTICAL RECEIVER
OUTPOL
VCC
IN+
IN-
MAX3748/
MAX3748A
RSSI TH
GND
RTH
C1
0.1µF
*FUTURE PRODUCT.
Features
o SFP Reference Design Available
o 16-Pin QFN Package with 3mm ✕ 3mm Footprint
o Single +3.3V Supply Voltage
o 86ps Rise and Fall Time
o Loss of Signal with Programmable Threshold
o RSSI Interface (with MAX3744 TIA)
o Output Disable
o Polarity Select
o 8.5ps_P-P Deterministic Jitter (3.2Gbps)
Ordering Information
PART
TEMP RANGE
MAX3748ETE -40°C to +85°C
MAX3748AETE -40°C to +85°C
*EP = Exposed pad.
PIN-
PACKAGE
16 QFN-EP*
16 QFN-EP*
PACKAGE
CODE
T1633-3
T1633-3
Functional Diagram and Pin Configuration appear at end of
data sheet.
Typical Operating Circuits
0.1µF
SUPPLY FILTER
CAZ1 CAZ2
HOST BOARD
HOST FILTER
VCC_RX
OUT+
OUT-
0.1µF
0.1µF
50Ω
SERDES
50Ω
DISABLE LOS
4.7kΩ TO 10kΩ
VCC_HOST
LOS
Typical Operating Circuits continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products 1
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