Datasheet

3.3 V, ±15 kV ESD-Protected, Half- and
Full-Duplex, RS-485/RS-422 Transceivers
ADM3070E/ADM3071E/ADM3072E/ADM3073E/ADM3074E/ADM3075E/ADM3076E/ADM3077E/ADM3078E
Rev. E
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FEATURES
TIA/EIA RS-485/RS-422 compliant
±15 kV ESD protection on RS-485 input/output pins
Data rates
ADM3070E/ADM3071E/ADM3072E: 250 kbps
ADM3073E/ADM3074E/ADM3075E: 500 kbps
ADM3076E/ADM3077E/ADM3078E: 16 Mbps
Half- and full-duplex options
True fail-safe receiver inputs
Up to 256 nodes on the bus
−40°C to +125°C temperature option
Hot-swap input structure on DE and
RE
pins
Reduced slew rates for low EMI
Low power shutdown current (all except ADM3071E/
ADM3074E/ADM3077E)
Outputs high-Z when disabled or powered off
Common-mode input range: −7 V to +12 V
Thermal shutdown and short-circuit protection
8-lead and 14-lead narrow SOIC packages
APPLICATIONS
Power/energy metering
Industrial control
Lighting systems
Telecommunications
Security systems
Instrumentation
GENERAL DESCRIPTION
The ADM307xE are 3.3 V, low power data transceivers with
±15 kV ESD protection suitable for full- and half-duplex
communication on multipoint bus transmission lines. They
are designed for balanced data transmission, and they comply
with TIA/EIA standards: RS-485 and RS-422.
The devices have a ⅛ unit load receiver input impedance, which
allows up to 256 transceivers on a bus. Because only one driver
should be enabled at any time, the output of a disabled or powered-
down driver is tristated to avoid overloading the bus.
The receiver inputs have a true fail-safe feature, which eliminates
the need for external bias resistors and ensures a logic high
output level when the inputs are open or shorted. This guar-
antees that the receiver outputs are in a known state before
communication begins and when communication ceases.
FUNCTIONAL BLOCK DIAGRAMS
ADM3070E/
ADM3073E/
ADM3076E
RO
RE
DE
DI
V
CC
A
B
Z
Y
GND
R
D
06285-001
Figure 1.
ADM3071E/
ADM3074E/
ADM3077E
RO
DI
V
CC
A
B
Z
Y
GND
R
D
0
6285-002
Figure 2.
ADM3072E/
ADM3075E/
ADM3078E
RO
RE
DE
DI
V
CC
A
B
GND
D
R
06285-003
Figure 3.