Document
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
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 powereddown 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 guarantees that the receiver outputs are in a known state before communication begins and when communication ceases.
FUNCTIONAL BLOCK DIAGRAMS
VCC
ADM3070E/ ADM3073E/ ADM3076E
RO R RE DE
DI D
A B
Z Y
06285-001
GND
Figure 1.
VCC
ADM3071E/ ADM3074E/ ADM3077E
A
RO
R B
06285-002
DI D
Z Y
GND
Figure 2.
VCC
ADM3072E/ ADM3075E/ ADM3078E
RO R RE DE
DI D
A B
GND
Figure 3.
06285-003
Rev. E
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ADM3070E/ADM3071E/ADM3072E/ADM3073E/ADM3074E/ADM3075E/ADM3076E/ADM3077E/ADM3078E
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications.........................................................................