LTC2850/LTC2851/LTC2852
3.3V 20Mbps RS485/RS422
Transceivers
FEATURES DESCRIPTION
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3.3V Supply Voltage
The LTC 2850, LTC2851 and LTC2852 are low power,
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20Mbps Maximum Data Rate
20Mbps RS485/RS422 transceivers operating on 3.3V
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No Damage or Latchup Up to 15kV HBM
supplies. The receiver has a one-eighth unit load supporting
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High Input Impedance Supports 256 Nodes
up to 256 nodes per bus (C-, I-grade), and a failsafe feature
(C-, I-Grade)
that guarantees a high output state under conditions of
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Operation Up to 125C (H-Grade)
floating or shorted inputs.
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Guaranteed Failsafe Receiver Operation Over the
The driver maintains a high output impedance over the
Entire Common Mode Range
entire common mode range when disabled or when the
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Current Limited Drivers and Thermal Shutdown
supply is removed. Excessive power dissipation caused by
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Delayed Micropower Shutdown: 5A Maximum
bus contention or a fault is prevented by current limiting
(C-, I-Grade)
all outputs and by thermal shutdown.
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Power Up/Down Glitch-Free Driver Outputs
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Enhanced ESD protection allows these parts to withstand
Low Operating Current: 370A Typical in
up to 15kV (human body model) on the transceiver
Receive Mode
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interface pins without latchup or damage.
Compatible with TIA/EIA-485-A Specifications
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Available in 8-Pin and 10-Pin 3mm 3mm DFN,
PART NUMBER DUPLEX PACKAGE
8-Pin and 10-Pin MSOP, and 8-Pin and 14-Pin
LTC2850 Half SO-8, MSOP-8, DFN-8
SO Packages
LTC2851 Full SO-8, MSOP-8, DFN-8
LTC2852 Full SO-14, MSOP-10, DFN-10
APPLICATIONS
L, LT, LTC, LTM, Linear Technology, the Linear logo and Module are registered trademarks of
n Linear Technology Corporation. All other trademarks are the property of their respective owners.
Low Power RS485/RS422 Transceiver
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Level Translator
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Backplane Transceiver
TYPICAL APPLICATION
LTC2850 at 20Mbps Into 54
LTC2850
RO1
V
CC1
R
RE1 DI
R
T
A
DE1
D
DI1
GND1
B
2V/DIV
A-B
LTC2850
R
T
RO2
V
CC2
R
RE2
285012 TA01b
20ns/DIV
DE2
DI2 D
GND2
285012 TA01a
285012fe
1
For more information www.linear.com/LTC2850LTC2850/LTC2851/LTC2852
ABSOLUTE MAXIMUM RATINGS (Note 1)
Supply Voltage (V ) ................................... 0.3V to 7V Operating Temperature (Note 4)
CC
Logic Input Voltages (RE, DE, DI) ................ 0.3V to 7V LTC285xC ................................................ 0C to 70C
Interface I/O: LTC285xI .............................................40C to 85C
A, B, Y, Z ....................................... (V 15V) to 15V LTC285xH .......................................... 40C to 125C
CC
Receiver Output Voltage (RO) .......0.3V to (V + 0.3V) LTC285xMP ....................................... 55C to 125C
CC
Storage Temperature Range .................. 65C to 150C
Lead Temperature (Soldering, 10 sec)
MSOP ...............................................................300C
PIN CONFIGURATION
LTC2850
TOP VIEW
TOP VIEW
TOP VIEW
RO 1 8 V
RO 1 8 V
CC CC
RO 8 V
1
CC
RE 2 7 B
RE 2 7 B
RE 2 7 B
9
DE 3 6 A
DE 3 6 A
DE 3 6 A
DI 4 5 GND
DI 4 5 GND
DI GND
4 5
MS8 PACKAGE
8-LEAD PLASTIC MSOP
S8 PACKAGE
DD PACKAGE
T = 150C, = 200C/W, = 40C/W
JMAX JA JC
8-LEAD PLASTIC SO
8-LEAD (3mm 3mm) PLASTIC DFN
T = 150C, = 150C/W, = 39C/W
JMAX JA JC
T = 150C, = 43C/W, = 3C/W
JMAX JA JC
EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB
LTC2851
TOP VIEW
TOP VIEW
TOP VIEW
V 1 8 A
CC
V 1 8 A
CC
V 1 8 A
RO 2 7 B CC
RO 7 B RO 2 7 B
9 2
DI Z
3 6
DI 3 6 Z
DI 3 6 Z
GND 4 5 Y
GND 4 5 Y
GND Y
4 5
MS8 PACKAGE
8-LEAD PLASTIC MSOP
DD PACKAGE
S8 PACKAGE
T = 150C, = 200C/W, = 40C/W
JMAX JA JC
8-LEAD (3mm 3mm) PLASTIC DFN
8-LEAD PLASTIC SO
T = 150C, = 150C/W, = 39C/W
JMAX JA JC
T = 150C, = 43C/W, = 3C/W
JMAX JA JC
EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB
LTC2852
TOP VIEW
TOP VIEW
NC 1 14 V
CC
RO 10 V
1 TOP VIEW
CC
RO 2 13 NC
RE 2 9 A 10
RO 1 V
CC
RE 3 12 A
9 A
RE 2
11
DE 3 8 B
8 B
DE 3
DE 4 11 B
DI 4 7 Z
7 Z
DI 4
DI 5 10 Z
6 Y
GND 5 6 Y GND 5
GND 6 9 Y
MS PACKAGE
DD PACKAGE
10-LEAD PLASTIC MSOP
GND 7 8 NC
10-LEAD (3mm 3mm) PLASTIC DFN
T = 150C, = 120C/W, = 45C/W
JMAX JA JC
T = 150C, = 43C/W, = 3C/W
JMAX JA JC
S PACKAGE
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
14-LEAD PLASTIC SO
T = 150C, = 88C/W, = 37C/W
JMAX JA JC
285012fe
2
For more information www.linear.com/LTC2850