LTM2885
6500V Isolated
RMS
RS485/RS422 Module
Transceiver + Power
FEATURES DESCRIPTION
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RS485/RS422 Transceiver: 6500V for 1 Minute The LTM 2885 is a complete galvanically isolated
RMS
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Reinforced Insulation full-duplex RS485/RS422 Module (micromodule)
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Isolated DC Power: 5V at 200mA transceiver. No external components are required. A
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single supply powers both sides of the interface through
No External Components Required
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an integrated, isolated, low noise, efficient 5V output
20Mbps or Low EMI 250kbps Data Rate
n DC/DC converter.
High ESD: 15kV HBM on Transceiver Interface
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High Common Mode Transient Immunity: 50kV/s
Coupled inductors and an isolation power transformer
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Integrated Selectable 120 Termination
provide 6500V of isolation between the line transceiver
RMS
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Extended Creepage and Clearance ~14.6mm
and the logic interface. This device is ideal for systems
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1.62V to 5.5V Logic Supply Pin for Flexible
where the ground loop is broken allowing for large common
Digital Interface
mode voltage variation. Uninterrupted communication is
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Maximum Continuous Working Voltage: 690V
RMS guaranteed for common mode transients up to 50kV/s.
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High Input Impedance Failsafe RS485 Receiver
Maximum data rates are 20Mbps or 250kbps in slew
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Current Limited Drivers and Thermal Shutdown
limited mode. Transmit data, DI, and receive data, RO, are
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Compatible with TIA/EIA-485-A and PROFIBUS
implemented with event driven low jitter processing. The
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High Impedance Output During Internal Fault Condition
receiver has a one-eighth unit load supporting up to 256
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Low Current Shutdown Mode (< 10A)
nodes per bus. A logic supply pin allows easy interfacing
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General Purpose CMOS Isolated Channel
with different logic levels from 1.62V to 5.5V, independent
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22mm 9mm 5.16mm Surface Mount BGA Package
of the main supply.
Enhanced ESD protection allows this part to withstand up
APPLICATIONS
to 15kV (human body model) on the transceiver interface
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Isolated RS485/RS422 Interface
pins to isolated supplies and 25kV through the isolation
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Industrial Networks
barrier to logic supplies without latch-up or damage.
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Breaking RS485 Ground Loops
L, LT, LTC, LTM, Linear Technology, the Linear logo and Module are registered trademarks of
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Analog Devices, Inc. All other trademarks are the property of their respective owners.
Isolated PROFIBUS-DP Networks
TYPICAL APPLICATION
Isolated Half-Duplex RS485 Module Transceiver LTM2885 Operating Through 100kV/s CM Transients
5V
V
CC LTM2885 DI
V 5V
CC2
5V/DIV
PWR
OUT
V A RO
L
5V/DIV
RO
B
RE
TWISTED-PAIR MULTIPLE SWEEPS
OF COMMON MODE
CABLE
TE
TRANSIENTS
DE
Y
DI 300V/DIV
Z
2885 TA01b
20ns/DIV
GND GND2
2885 TA01a
2885fa
1
For more information www.linear.com/LTM2885
ISOLATION BARRIERLTM2885
ABSOLUTE MAXIMUM RATINGS
(Note 1)
Signal Voltages SLO,
V to GND .................................................. 0.3V to 6V
D to GND2 ....................................0.3V to V +0.3V
CC
IN CC2
V to GND2 ............................................... 0.3V to 6V
Operating Temperature Range (Note 4)
CC2
V to GND .................................................... 0.3V to 6V
LTM2885C ............................................... 0C to 70C
L
Interface Voltages
LTM2885I ............................................40C to 85C
(A, B, Y, Z) to GND2 ........................ V 15V to 15V
LTM2885H ......................................... 40C to 105C
CC2
(A-B) with Terminator Enabled ..............................6V
Maximum Internal Operating Temperature ............ 125C
Signal Voltages ON, RO, DI, DE,
Storage Temperature Range .................. 55C to 125C
RE, TE, D to GND ......................... 0.3V to V +0.3V Peak Body Reflow Temperature ............................ 245C
OUT L
PIN CONFIGURATION
TOP VIEW
7
ON
6
V V V
L CC CC2
5
RO A
4
RE B
3
DE Z
2
DI GND GND2 Y
1
TE DOUT NC NC DIN SLO
A B C D E F G H J K L M N P R S T
BGA PACKAGE
42-PIN (22mm 9mm 5.2mm)
T = 125C, = 35C/W, = 23.9C/W, = 29.6C/W, = 22.7C/W
JMAX JA JC(BOTTOM) JC(TOP) JBOARD
VALUES DETERMINED PER JESD51-9, WEIGHT = 1.9g
ORDER INFORMATION