LTC1688/LTC1689
100Mbps RS485
Hot Swapable Quad Drivers
FEATURES
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DESCRIPTIO
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Ultrahigh Speed:
100Mbps
Guaranteed Propagation Delay: 8ns
±
4ns
Over Temperature
Low Channel-to-Channel Skew: 500ps Typ
Hot Swap
TM
Capable
50Mbps Operation with V
DD
= 3V
Low t
PLH
/t
PHL
Skew: 500ps Typ
Driver Outputs Maintain High Impedance in
Three-State or with Power Off
Short-Circuit Protected: 3mA Typ Output Current
for an Indefinite Short
Thermal Shutdown Protected
Single 5V or 3V Supply
Pin Compatible with LTC486/LTC487
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.
APPLICATIO S
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High Speed RS485 Twisted-Pair Drivers
High Speed Backplane Drivers
Complementary Clock Drivers
STS-1/OC-1 Data Drivers
SCSI Drivers
TYPICAL APPLICATIO
50Mbps RS485 Data Connection
2V/DIV
DRIVER
100Ω
100Ω
2V/DIV
RECEIVER
2V/DIV
100 FT CATEGORY 5 UTP
1/4 LTC1688
1/4 LTC1518
1688/89 TA01
5V/DIV
U
20ns Pulse Across 100 Feet
of Category 5 UTP
DRIVER INPUT
DRIVER OUTPUTS
CABLE DELAY
RECEIVER INPUT
RECEIVER OUTPUT
20ns/DIV
1688/89 TA02
U
U
16889fa
1
LINEAR_DIMENSIONS [ LINEAR DIMENSIONS SEMICONDUCTOR ]
