ADM1487E Datasheet | Analog Devices

FEATURES TIA/EIA RS-485/RS-422 pliant ESD protection on RS-485 I/O pins ±15 k V human body model (HBM) Data rates ADM487E: 250 kbps ADM485E/ADM1487E: 2.5 Mbps Half-duplex Reduced slew rates for low EMI mon-mode input range: - 7 V to +12 V Thermal shutdown and short-circuit protection 8-lead SOIC packages ADM487EW qualified for automotive applications APPLICATIONS Energy/power metering Lighting systems Industrial control Telemunications Security systems Instrumentation GENERAL DESCRIPTION The ADM485E/ADM487E/ADM1487E are 5 V, low power data transceivers with ±15 k V ESD protection suitable for halfduplex munication on multipoint bus transmission lines. They are designed for balanced data transmission and ply with Telemunication Industry Association/Electronics Industries Association (TIA/EIA) standards RS-485 and RS-422. The ADM487E and ADM1487E have a 1/4 unit load receiver input impedance that allows up to 128 transceivers on a bus, whereas the ADM485E allows up to 32 transceivers on a bus. Because only one driver is enabled at any time, the output of a disabled or power-down driver is three-stated to avoid overloading the bus. FUNCTIONAL BLOCK DIAGRAM ADM485E/ ADM487E/ ADM1487E 06356-001 Figure 1. The driver outputs are slew rate limited to reduce EMI and data errors caused by reflections from improperly terminated buses. Excessive power dissipation caused by bus contention or output shorting is prevented with a thermal shutdown circuit. The parts are fully specified over the industrial temperature ranges and are available in 8-lead SOIC packages. Table 1. Selection Table Part Number ADM485E ADM487E ADM1487E Half-/Full Duplex Half Half Half Guaranteed Data Rate (Mbps) 2.5 0.25 2.5 Slew Rate Limited No Yes No Low Power Shutdown No Yes No Driver/Receiver Enable Yes Yes Yes Quiescent Current (μA) 300 120 230 Number of Nodes on Bus 32 128 128 Pin Count 8 8 8 Rev. B Information furnished by Analog Devices is believed to...