- 您现在的位置：买卖IC网 > PDF目录382336 > MM74HC943 (NATIONAL SEMICONDUCTOR CORP) Low-Voltage Adjustable Precision Shunt Regulator 3-TO-92 -40 to 85 PDF资料下载
参数资料
| 型号： | MM74HC943 |
| 厂商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分类： | 调制器/解调器 |
| 英文描述： | Low-Voltage Adjustable Precision Shunt Regulator 3-TO-92 -40 to 85 |
| 中文描述： | 0.3 kbps DATA, MODEM, PDIP20 |
| 文件页数： | 1/8页 |
| 文件大小： | 153K |
| 代理商： | MM74HC943 |
TL/F/5349
M
PRELIMINARY
January 1988
MM74HC943 300 Baud Modem
General Description
The MM74HC943 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.
The MM74HC943 utilizes advanced silicon-gate CMOS
technology. Switched capacitor techniques are used to pe-
form analog signal processing.
MODULATOR SECTION
The modulator contains a frequency synthesizer and a sine
wave synthesizer. It produces a phase coherent frequency
shift keyed (FSK) output.
LINE DRIVER AND HYBRID SECTION
The line driver and hybrid are designed to facilitate connec-
tion to a 600
X
phone line. They can perform two to four wire
conversion and drive the line at a maximum of
b
9 dBm.
DEMODULATOR SECTION
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.
Features
Y
5V supply
Y
Drives 600
X
at
b
9 dBm
Y
All filters on chip
Y
Transmit level adjustment compatible with universal
service order code
Y
TTL and CMOS compatible logic
Y
All inputs protected against static damage
Y
Low power consumption
Y
Full duplex answer or originate operation
Y
Analog loopback for self test
Y
Power down mode
Applications
Y
Built-in low speed modems
Y
Remote data collection
Y
Radio telemetry
Y
Credit verification
Y
Stand-alone modems
Y
Point-of-sale terminals
Y
Tone signaling systems
Y
Remote process control
Connection and Block Diagrams
Dual-In-Line Package
TL/F/5349–1
Order Number MM74HC943
TL/F/5349–2
TRI-STATE
é
is a registered trademark of National Semiconductor Corporation.
C
1995 National Semiconductor Corporation
RRD-B30M105/Printed in U. S. A.
相关PDF资料 |
PDF描述 |
|---|---|
| MM74HC943J | Low-Voltage Adjustable Precision Shunt Regulator 3-TO-92 -40 to 85 |
| MM74HC943N | Low-Voltage Adjustable Precision Shunt Regulator 3-SOT-89 -40 to 85 |
| MM74HCT109 | ANA 5V USR DFINED LIN REG; Package: SO-16 WB; No of Pins: 16; Container: Tape and Reel; Qty per Container: 1000 |
| MM54HCT109 | Dual J-K Flip-Flops with Preset and Clear |
| MM54HCT109J | Dual J-K Flip-Flops with Preset and Clear |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MM74HC943J | 制造商:NSC 制造商全称:National Semiconductor 功能描述:300 Baud Modem |
| MM74HC943N | 制造商:NSC 制造商全称:National Semiconductor 功能描述:300 Baud Modem |
| MM74HCA393M | 制造商:Texas Instruments 功能描述: |
| MM74HCCOOM | 制造商:Fairchild Semiconductor Corporation 功能描述: |
| MM74HCOOM | 制造商:Texas Instruments 功能描述: |
发布紧急采购，3分钟左右您将得到回复。