描述 Description

The ST485A is a low power, high speed transceiver for RS-485 and RS-422 communications. The device contains one driver and one receiver in half duplex configuration. The ST485A draws 3 mA (typ.) of supply current when unloaded or fully loaded with disabled drivers. It operates from a single 5 V supply.

Driver is short-circuit current limited and is protected against excessive power dissipation by thermal shutdown circuitry that place the driver outputs into a high-impedance state. The receiver input has a fail-safe feature that guarantees a logic high output if both inputs are open circuit.

The ST485A is designed for bi-directional data communications or multipoint bus transmission lines.

特性 Features

? Latch-up free up to 500 mA
? Current limiting and thermal shutdown for driver overload protection
? Operate from single 5 supply
? 70mV typical input hysteresis
? Low supply current: 5 mA max
? Designed for RS 485 interface applications
? High data rate > 30 Mbps
? Driver maintains high impedance in 3-state or with the power off
? ±4 kV ESD protection
? -7 to 12 common mode input voltage range

簡介

ST485AB屬于集成電路（IC）的驅(qū)動器接收器收發(fā)器。由制造生產(chǎn)的ST485AB驅(qū)動器，接收器，收發(fā)器該系列產(chǎn)品的主要功能是提供必需的硬件資源，以通過延長電纜或印制線進行通信。確切的功能會因所采用的通信協(xié)議而異，可能包括諸如瞬態(tài)抑制之類的功能，這些功能對于通信用途可能并非絕對必要，但對于可能的使用環(huán)境卻是明智之選。