MAX4890_07 Datasheet, PDF (1/17 Pages) Maxim Integrated Products – 10/100/1000 Base-T Ethernet LAN Switch

19-3577; Rev 2; 8/07
10/100/1000 Base-T Ethernet LAN Switch
General Description
The MAX4890/MAX4891/MAX4892 high-speed analog
switches meet the needs of 10/100/1000 Base-T appli-
cations. These devices switch the signals from two
interface transformers and connect the signals to a sin-
gle 10/100/1000 Base-T Ethernet PHY, simplifying
docking station design and reducing manufacturing
costs. The MAX4890/MAX4891/MAX4892 can also
route signals from a common interface transformer to
two different boards in board-redundancy applications.
The MAX4890/MAX4891/MAX4892 switches provide an
extremely low capacitance and on-resistance to meet
Ethernet insertion and return-loss specifications. The
MAX4891/MAX4892 feature one and three built-in LED
switches, respectively.
The MAX4890/MAX4891/MAX4892 are available in
space-saving 32- and 36-lead TQFN packages,
significantly reducing the required PC board area.
These devices operate over the -40°C to +85°C tem-
perature range.
Applications
Notebooks and Docking Stations
Servers and Routers with Ethernet Interfaces
Board-Level Redundancy Protection
SONET/SDH Signal Routing
T3/E3 Redundancy Protection
Video Switching
Features
♦ Single +3.0V to +3.6V Power-Supply Voltage
♦ Low On-Resistance (R_ON): 4Ω (typ), 6.5Ω (max)
♦ Ultra-Low On-Capacitance (C_ON): 6.5pF (typ)
♦ Low < 200ps Bit-to-Bit Skew
♦ -3dB Bandwidth: 1GHz
♦ Optimized Pin-Out for Easy Transformer and PHY
Interface
♦ Built-In LED Switches for Switching Indicators to
Docking Station
♦ Low 450µA (max) Quiescent Current
♦ Bidirectional 8 to 16 Multiplexer/Demultiplexer
♦ Space-Saving Packages
32-Pin, 5mm x 5mm, TQFN Package
36-Pin, 6mm x 6mm, TQFN Package
Ordering Information
PART
PIN-PACKAGE
LED SWITCHES
MAX4890ETJ
32 TQFN-EP*
—
MAX4891ETJ
32 TQFN-EP*
1
MAX4892ETX
36 TQFN-EP*
3
Note: All devices are specified for operation in the -40°C to
+85°C temperature range.
*EP = Exposed pad.
Pin Configurations
TOP VIEW
32 31 30 29 28 27 26 25
A2 1
A3 2
N.C. 3
N.C. 4
N.C. 5
N.C. 6
A4 7
A5 8
24 2B1
23 3B1
22 2B2
MAX4890
21 3B2
20 4B1
19 5B1
*EP
18 4B2
17 5B2
9 10 11 12 13 14 15 16
Functional Diagrams and Typical Operating Circuit appear
at end of data sheet.
TQFN
*EP = EXPOSED PAD. CONNECT EP TO GND OR LEAVE UNCONNECTED
Pin Configurations continued at end of data sheet.
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