74hc123d中文资料

概述

RTL8019AS采用100脚PQFP封装，其主要引角功能如下：

引角1－4,97－100：中断控制INT0-7;

引角33：复位控制；

引脚34：使能控制角AEN,低电平有效；

引脚6,7,70，：数字电源，＋5V；

引脚14,28,83,86：数字地GND;

引脚47,57：模拟电源：＋5V；

引脚44,52：模拟地；

引脚7－13,15,16,18－27：ISA地址总线；

引脚36－43,87,88,90－95：ISA数据总线；

引脚31：Boot ROM读操作控制；

引脚32：Boot ROM写操作控制；

引脚62：RX接收数据显示LED1脚；

引脚63：TX发送数据显示LED2脚；

引脚58,59:接收数据TP IN+/-;

引脚45,46:发送数据TP OUT+/-;

引脚50,51:外接晶体。

特性

产品种类: 单稳态多谐振荡器

逻辑系列: 74HC

逻辑类型: Dual Monostable Multivibrator

封装 / 箱体: SOT-109

传播延迟时间: 51 ns

最大功率耗散: 500 mW

最大工作温度: 125 C

最小工作温度: - 40 C

封装: Tube

安装风格: SMD/SMT

工作电源电压: 2 V to 6 V

参数

暂无74HC123D的参数信息

引脚图与功能

暂无74HC123D的引脚图与功能信息

1. General description

The 74HC123; 74HCT123 ar e hig h-sp eed Si-g ate CMOS d evices and ar e pin compatible

with Low-power Schottky TTL (LSTTL). They are specified in compliance with JEDEC

standard no. 7A.

The 74HC123; 74HCT123 are dual retriggerable monostable multivibrators with output

pulse width control by three methods:

1. The basic pulse is programmed by selection of an external resistor (R

EXT

) and

capacitor (C

EXT

).

2. Once triggered, the basic output pulse width may be extended retriggering the

gated active LOW- going edge input (nA

) or the active HIGH-going edge in put (nB). By

repeating this process, the ou tput pulse period ( nQ = HIGH, nQ

by

= LOW) can be made

as long as desired. Alternatively an output delay can be terminated at any time by a

LOW-going edge on input nRD

, which also inhibits the triggering.

3. An internal connection from nRD

to the input gates makes it possible to trigger the

circuit by a HIGH-going signal at input nRD

as shown in Table 3.

Schmitt-trigger action in the nA

and nB inputs, makes the circuit highly tolerant to slower

input rise and fall times.

The 74HC123; 74HCT123 are identical to the 74HC423; 74HCT423 but can be triggered

via the reset input.

2. Features and benefits

DC triggered from active HIGH or active LOW inputs

Retriggerable for very long pulses up to 100 % duty factor

Direct reset terminates output puls e

Schmitt-trigger action on all inputs except for the reset input

ESD protection:

HBM JESD22-A114F exceeds 2000 V

MM JESD22-A115-A exceeds 200 V

Specified from 40 Cto+85C and from 40 Cto+125C