SN74HC257NSR集成电路（IC）的信号开关多路复用器解码器规格书PDF中文资料

SN74HC257NSR属于集成电路（IC）的信号开关多路复用器解码器。由德州仪器制造生产的SN74HC257NSR信号开关，多路复用器，解码器逻辑型信号开关、多路复用器和编码器 IC 可用于对以数字格式表示数据的电信号进行路由和选择。这些器件与设计用于模拟信号的类似产品有所不同，它们保留的信息表示为两个电状态之一，而不是两个外部界限内的无穷变化量。

1 Features

• Wide operating voltage range of 2 V to 6 V

• High-current inverting outputs can drive up to 15

LSTTL loads

• Low power consumption, 80-μA max ICC

• 'HC257 typical tpd = 9 ns

• 'HC258 typical tpd = 12 ns

• ±6-mA output drive at 5 V

• Low input current of 1 μA max

• Provides bus interface from multiple sources in

high-performance systems

2 Description

The SNx4HC257 and '258 contain four data selectors/

multiplexers to select one of two data sources. All

channels are controlled by the same address select

(A/B) input, and active-low strobe (G) input. A high

level at the G terminal forces all outputs into the highimpedance

state. The '257 has non-inverted outputs

and the '258 has inverted outputs.