PRELIMINARY TECHNICAL DATA
Enhanced Slew Rate Limiting for Error-Free Data
Fail-Safe Receiver Operation while Maintaining
Low-Current (1nA) Shutdown Mode
High Input Impedance — Up to 256 Transceivers on Bus
±15kV ESD Protection (Human Body Model) on
RS-485 I/O pins
Pin-Compatible with Industry Standard 75176
Enhanced Replacement for Industry-Standard Parts
LANs for Industrial Control Applications
The ADM3082/ADM3085/ADM3088 are high-speed
RS-485/RS-422 transceivers consisting of one driver and one
receiver per package. The devices feature fail-safe operation,
ensuring a logic-high receiver output when the receiver in-
puts are open-circuit or short-circuit. This guarantees that
the receiver output will be high if all the transmitters on a
terminated bus are disabled (high-impedance).
The ADM3082 has a slew-rate limited driver to minimize
electromagnetic interference (EMI) and reduce reflections
caused by incorrectly terminated cables. This allows error-
free transmission at data rates up to 115kbps.
The ADM3085 offers a higher slew rate allowing data rates
up to 500kbps, while the ADM3088 has a driver whose slew
rate is not limited, allowing data rates up to 10Mbps.
All devices in the family feature ±15kV electrostatic dis-
charge (ESD) protection and high receiver input imped-
ance (1/8 unit load), allowing up to 256 transceivers on
the bus. The devices have low current drain of 375µA un-
loaded, or fully loaded with the drivers disabled, and fea-
ture an ultra-low power (1nA) shutdown mode.
FUNCTIONAL BLOCK DIAGRAM
REV. PrA 02/02
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