MAX4890/MAX4891/MAX4892
Analog Signal Levels
The on-resistance of the MAX4890/MAX4891/MAX4892
is very low and stable as the analog input signals are
swept from ground to V+ (see the
Typical Operating
Characteristics
). The switches are bidirectional, allow-
ing A_ and _B_ to be configured as either inputs or out-
puts.
ESD Protection
The MAX4890/MAX4891/MAX4892 are characterized
using the Human Body Model for ±2kV of ESD protec-
tion. Figure 8 shows the Human Body Model, and Figure
9 shows the current waveform the Human Body Model
generates when discharged into a low-impedance load.
This model consists of a 100pF capacitor charged to the
ESD voltage of interest, which is then discharged into the
test device through a 1.5kΩ resistor.
Applications Information
Typical Operating Circuit
The
Typical Operating Circuit
depicts the MAX4890/
MAX4891/MAX4892 in a 10/100/1000 Base-T docking
station application.
Line-Card Redundancy (Ethernet T3/E3)
Figure 10 shows the MAX4890/MAX4891/MAX4892 in a
line-card redundancy configuration.
Power-Supply Sequencing and
Overvoltage Protection
Caution: Do not exceed the absolute maximum ratings.
Stresses beyond the listed ratings may cause perma-
nent damage to the device.
Proper power-supply sequencing is recommended for
all CMOS devices. Always apply V+ before applying
analog signals, especially if the analog signal is not
current limited.
Layout
High-speed switches require proper layout and design
procedures for optimum performance. Keep design-
controlled-impedance printed circuit board traces as
short as possible. Ensure that bypass capacitors are as
close to the device as possible. Use large ground
planes where possible.
10/100/1000 Base-T Ethernet LAN Switch
10 ______________________________________________________________________________________
Figure 4. Differential Crosstalk
