LTC2856-1/LTC2856-2
LTC2857-1/LTC2857-2
LTC2858-1/LTC2858-2
20Mbps and Slew Rate
Limited 15kV RS485/RS422
Transceivers
DESCRIPTION
FEATURES
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20Mbps or Low EMI 250kbps Maximum Data Rate
No Damage or Latchup to ESD: ±15kV HBM
High Input Impedance Supports 256 Nodes
Guaranteed Failsafe Receiver Operation Over the
Entire Common Mode Range
Current Limited Drivers and Thermal Shutdown
Delayed Micropower Shutdown: 5µA Maximum
Power Up/Down Glitch-Free Driver Outputs
Low Operating Current: 900µA Maximum in Receive
Mode
Compatible with TIA/EIA-485-A Specifications
Available in 8-Lead and 10-Lead 3mm × 3mm DFN
and 8-Lead and 10-Lead MSOP Packages
APPLICATIONS
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Low Power RS485/RS422 Transceiver
Level Translator
Backplane Transceiver
The LTC®2856-1, LTC2856-2, LTC2857-1, LTC2857-2,
LTC2858-1 and LTC2858-2 are low power, RS485/RS422
transceivers operating on 5V supplies at maximum data
rates of 20Mbps or 250kbps for low EMI. The receiver has
a one-eighth unit load, supporting up to 256 nodes per
bus, 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 thermal shutdown.
Enhanced ESD protection allows these parts to withstand
±15kV (human body model) on the transceiver interface
pins without latchup or damage.
Product Selection Guide
MAX DATA
RATE (Mbps)
DUPLEX
PACKAGE
LTC2856-1
20
Half
MSOP-8, DFN-8
LTC2856-2
0.25
Half
MSOP-8, DFN-8
20
Full
MSOP-8, DFN-8
LTC2857-2
0.25
Full
MSOP-8, DFN-8
LTC2858-1
20
Full
MSOP-10, DFN-10
LTC2858-2
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
PART
NUMBER
LTC2857-1
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0.25
Full
MSOP-10, DFN-10
TYPICAL APPLICATION
LTC2858-1 at 20Mbps
LTC2856-1
RO1
RE1
R
VCC1
DE1
D
LTC2856-1
RO2
RE2
R
Y
GND1
Z
2V/DIV
DI1
DI
RT
VCC2
RT
Y-Z
DE2
DI2
D
GND2
285678 TA01a
20ns/DIV
2856 TA01b
285678fb
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