LTC2854_15 Datasheet, PDF (1/16 Pages) Linear Technology – 3.3V 20Mbps RS485/RS422 Transceivers with Integrated Switchable Termination

FEATURES
■ _{Integrated, Logic-Selectable 120Ω Termination}
Resistor
■ _{3.3V Supply Voltage}
■ _{20Mbps Maximum Data Rate}
■ _{No Damage or Latchup Up to ±25kV HBM}
■ _{High Input Impedance Supports 256 Nodes}
(C, I-Grade)
■ _{Operation Up to 125°C (H-Grade)}
■ _{Guaranteed Failsafe Receiver Operation Over the}
Entire Common Mode Range
■ _{Current Limited Drivers and Thermal Shutdown}
■ _{Delayed Micropower Shutdown: 5μA Maximum}
(C, I-Grade)
■ _{Power Up/Down Glitch-Free Driver Outputs}
■ _{Low Operating Current: 370μA Typical in}
Receive Mode
■ _{Compatible with TIA/EIA-485-A Specifications}
■ _{Available in 10-Pin 3mm × 3mm DFN, 12-Pin}
4mm × 3mm DFN and 16-Pin SSOP Packages
APPLICATIONS
■ _{Low Power RS485/RS422 Transceiver}
■ _{Level Translator}
■ _{Backplane Transceiver}
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
LTC2854/LTC2855
3.3V 20Mbps RS485/RS422
Transceivers with Integrated
Switchable Termination
DESCRIPTION
The LTC^®2854 and LTC2855 are low power, 20Mbps
RS485/RS422 transceivers operating on 3.3V supplies.
The receiver includes a logic-selectable 120Ω termina-
tion, one-eighth unit load supporting up to 256 nodes per
bus (C, I-Grade), and a failsafe feature that guarantees a
high output state under conditions of floating or shorted
inputs.
The driver maintains a high output impedance over the
entire common mode range when disabled or when the
supply is removed. Excessive power dissipation caused by
bus contention or a fault is prevented by current limiting
all outputs and by a thermal shutdown.
Enhanced ESD protection allows the LTC2854 to withstand
±25kV (human body model) and the LTC2855 to withstand
±15kV on the transceiver interface pins without latchup
or damage.
PRODUCT SELECTION GUIDE
PART NUMBER
LTC2854
LTC2855
DUPLEX
HALF
FULL
PACKAGE
DFN-10
SSOP-16, DFN-12
TYPICAL APPLICATION
RO
R
RE
TE
DE
DI
D
LTC2854
120Ω
LTC2854
120Ω
120Ω
LTC2854
R
RO
RE
TE
DE
D
DI
285455 TA01
R
D
RO RE TE DE DI
LTC2854 at 20Mbps into 54Ω
DI
A
B
2V/DIV
A-B
20ns/DIV
285455 TA01b
285455fb
1