LTC1688_15 Datasheet, PDF (1/12 Pages) Linear Technology – 100Mbps RS485 Hot Swapable Quad Drivers

FEATURES
s _{Ultrahigh Speed: 100Mbps}
s _{Guaranteed Propagation Delay: 8ns ±4ns}
Over Temperature
s _{Low Channel-to-Channel Skew: 500ps Typ}
s _{Hot Swap}^TM _Capable
s _{50Mbps Operation with VDD = 3V}
s _{Low tPLH/tPHL Skew: 500ps Typ}
s _{Driver Outputs Maintain High Impedance in}
Three-State or with Power Off
s _{Short-Circuit Protected: 3mA Typ Output Current}
for an Indefinite Short
s _{Thermal Shutdown Protected}
s _{Single 5V or 3V Supply}
s _{Pin Compatible with LTC486/LTC487}
U
APPLICATIO S
s _{High Speed RS485 Twisted-Pair Drivers}
s _{High Speed Backplane Drivers}
s _{Complementary Clock Drivers}
s _{STS-1/OC-1 Data Drivers}
s _{SCSI Drivers}
LTC1688/LTC1689
100Mbps RS485
Hot Swapable Quad Drivers
DESCRIPTIO
The LTC^®1688/LTC1689 are ultrahigh speed, differential
bus/line drivers that can operate at data rates up to
100Mbps. Propagation delay is guaranteed at 8ns ±4ns
over the full operating temperature range. These devices
operate over the full RS485 common mode range (– 7V
to 12V), and also meet RS422 requirements.
The driver outputs are Hot Swap capable, maintaining
backplane data integrity during board insertion and
removal. The drivers feature three-state outputs, maintain-
ing high impedance over the entire common mode range
(– 7V to 12V). Outputs also remain high impedance during
power-up and with the power off. A short-circuit feature
detects bus contention and substantially reduces driver
output current. Thermal shutdown circuitry protects the
parts from excessive power dissipation.
The LTC1688 allows all four drivers to be enabled together,
while the LTC1689 allows two drivers at a time to be
enabled.
The LTC1688/LTC1689 operate from a single 5V or 3V
supply and draw only 9mA of supply current.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Hot Swap is a trademark of Linear Technology Corporation.
TYPICAL APPLICATIO
50Mbps RS485 Data Connection
DRIVER
1/4 LTC1688
100Ω
100Ω
100 FT CATEGORY 5 UTP
RECEIVER
1/4 LTC1518
1688/89 TA01
20ns Pulse Across 100 Feet
of Category 5 UTP
2V/DIV
DRIVER INPUT
2V/DIV
2V/DIV
5V/DIV
DRIVER OUTPUTS
CABLE DELAY
RECEIVER INPUT
RECEIVER OUTPUT
20ns/DIV
1688/89 TA02
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