74VHC943

更新时间： 2024-10-01 00:01:23

品牌	Logo	应用领域
美国国家半导体 - NSC		调制解调器
页数	文件大小	规格书
13页	158K
描述
300 Baud Modem (5V Supply)

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中文翻译

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数据手册

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74VHC943 数据手册

PRELIMINARY

October 1995

74VHC943

300 Baud Modem (5V Supply)

General Description

Features

5V supply

The 74VHC943 is a full duplex low speed modem. It pro-

vides a 300 baud bidirectional serial interface for data com-

munication over telephone lines and other narrow band-

width channels. It is Bell 103 compatible.

Drives 600X at 9 dBm

All filters on chip

Transmit level adjustment compatible with universal

service order code

The 74VHC943 utilizes advanced silicon-gate CMOS tech-

nology. Switched capacitor techniques are used to perform

analog signal processing.

TTL and CMOS compatible logic

All inputs protected against static damage

Low power consumption

MODULATOR SECTION

Full duplex answer or originate operation

Analog loopback for self test

The modulator contains a frequency synthesizer and a sine

wave synthesizer. It produces a phase coherent frequency

shift keyed (FSK) output.

Power down mode

Direct Pin and function replacement for the 74HC943

LINE DRIVER AND HYBRID SECTION

The line driver and hybrid are designed to facilitate connec-

tion to a 600X phone line. They can perform two to four wire

conversion and drive the line at a maximum of 9 dBm.

Applications

Built-in low speed modems

Remote data collection

DEMODULATOR SECTION

Radio telemetry

The demodulator incorporates anti-aliasing filters, a receive

filter, limiter, discriminator, and carrier detect circuit. The

nine-pole receive filter provides 60 dB of transmitted tone

rejection. The discriminator is fully balanced for stable

operation.

Credit verification

Stand-alone modems

Point-of-sale terminals

Tone signaling systems

Remote process control

Commercial

74VHC943WM

74VHC943N

Package Number

M20B

Package Description

20-Lead Molded JEDEC SOIC (0.300 Wide)

N20A

20-Lead Molded DIP

Note: Surface mount packages are also available on Tape and Reel. Specify by appending the suffix letter

‘‘X’’ to the ordering code.

Connection Diagram

Pin Assignments for

SOIC and PDIP

TL/F/11679–1

TRI-STATEÉ is a registered trademark of National Semiconductor Corporation.

1995 National Semiconductor Corporation

TL/F/11679

RRD-B30M125/Printed in U. S. A.

12 3 4 5 6 7...13

中文翻译

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与74VHC943相关器件

型号	品牌	获取价格	描述	数据表
74VHC943N	NSC	获取价格	300 Baud Modem (5V Supply)
74VHC943NX	NSC	获取价格	300 Baud Modem (5V Supply)
74VHC943WM	NSC	获取价格	300 Baud Modem (5V Supply)
74VHC943WMX	NSC	获取价格	300 Baud Modem (5V Supply)
74VHC9541FT	TOSHIBA	获取价格	Octal Buffer, TSSOP20B
74VHC9595FT	TOSHIBA	获取价格	8-bit Shift Register, TSSOP16B
74VHCT00	STMICROELECTRONICS	获取价格	QUAD 2-INPUT NAND GATE
74VHCT00A	STMICROELECTRONICS	获取价格	QUAD 2-INPUT NAND GATE
74VHCT00A	FAIRCHILD	获取价格	Quad 2-Input NAND Gate
74VHCT00A_04	STMICROELECTRONICS	获取价格	QUAD 2-INPUT NAND GATE