ADM3491-1

Data Sheet FEATURES Operates with 3.3 V supply EIA RS-422 and RS-485 compliant over full CM range 19 kΩ input impedance Up to 50 transceivers on bus 20 Mbps data rate Short-circuit protection Specified over full temperature range Thermal shutdown Interoperable with 5 V logic 840 μA supply current 2 nA shutdown current Available in PDIP, SOIC, and TSSOP Meets IEC1000-4-4 (>1 kV) 8 ns skew Upgrade for MAX3491, SN75ALS180 3.3 V, Full-Duplex, 840 μA, 20 Mbps, EIA RS-485 Transceiver ADM3491-1 FUNCTIONAL BLOCK DIAGRAM ADM3491-1 RO R RE A B DE DI D Z Y 05234-001 Figure 1. APPLICATIONS Telecommunications DTE–DCE interface Packet switching Local area networks Data concentration Data multiplexers Integrated services digital network (ISDN) AppleTalk Industrial controls GENERAL DESCRIPTION The ADM3491-1 is a low power, differential line transceiver designed to operate using a single 3.3 V power supply. Low power consumption, coupled with a shutdown mode, makes it ideal for power-sensitive applications. It is suitable for communication on multipoint bus transmission lines. The ADM3491-1 is intended for balanced data transmission and complies with both Electronic Industries Association (EIA) Standards RS-485 and RS-422. It contains a differential line driver and a differential line receiver, making it suitable for fullduplex data transfer. The input impedance is 19 kΩ, allowing up to 50 transceivers to be connected on the bus. A thermal shutdown circuit prevents excessive power...