描述 Description

The ST490A is a low power transceiver for RS485 and RS-422 communications. The device contains one driver and one receiver in full duplex configuration. The ST490A draws 5mA (typ.) of supply current when unloaded or fully loaded with disabled drivers. It operates from a single 5V 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.

特性 Features

? Current limiting and thermal shutdown for driver overload protection
? ±4 kV ESD protection
? Low supply current: 5mA max
? 70mV typical input hysteresis
? -7V to 12V common mode input voltage range
? Operate from a single 5 V supply
? Designed for 25Mbps operation

簡介

ST490AB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ST490AB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。