CML無線調制解調器 CMX469AD3

CML無線調制解調器 CMX469AD3屬性

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CML無線調制解調器 CMX469AD3描述

CMX469A： 1200/2400/4800 Baud FFSK/MSK Modem

The CMX469A is a single-chip CMOS LSI circuit which operates as a full-duplex pin-selectable 1200, 2400 or 4800 baud FFSK Modem.The mark and space frequencies are 1200/1800, 1200/2400 and 2400/4800Hz respectively. Tone frequencies are phase continuous; transitions occur at the zero crossing point.Employing a common Xtal oscillator with a choice of two clock frequencies (1.008MHz or 4.032MHz) to provide baud-rate, transmit frequencies, and Rx and Tx synchronisation, the transmitter and receiver operate entirely independently including individual section powersave functions.

The CMX469A includes on-chip circuitry for Carrier Detect and Rx Clock recovery, both of which are made available as output pins. Rx, Tx and Carrier Detect paths each contain a bandpass filter to ensure the provision of optimum signal conditions both in the modem and for the Tx modulation circuitry.

The CMX469A demonstrates a high sensitivity and good bit-error-rate under adverse signal conditions; the carrier detect time constant is set by an external capacitor, whose value should be arranged as required to further enhance this product’s performance in high noise environments.

This low-power device requires few external components and is available in small outline plastic SOIC and TSSOP packages.

Features:
Selectable Data Rates: 1200/2400/4800 Baud
Full Duplex FFSK
Rx and Tx Bandpass Filters
Clock Recovery and Carrier Detect Facilities
Pin Selectable Xtal/Clock Inputs:1.008MHz or 4.032MHz
Simple Control: No μP Required

Applications:
Data-Over-Radio
PMR and Cellular Radio Signalling
Automatic Vehicle Location (Differential GPS) Links
Portable Data Terminals
Personal/Cordless Telephone
Industrial Control Signalling

Supply Requirement:
2.7 to 5.5 V


CMX469A是CML公司推出的FFSK／MSK全雙工MODEM芯片，它內部集成了載波檢測、RX時鐘恢復電路和振蕩電路，并具有很好的信噪比以及低電壓、低功耗等特性，能夠接收、發射FFSK／MSK信號，同時可提供收發時鐘。CMX469A的工作原理、應用電路和程序控制流程。 全雙工無線Modem芯片 ，它采用CMOS工藝制造，工作電壓為2.7Ｖ～5.5Ｖ，當電源電壓為３Ｖ時，它的典型工作電流為２ｍＡ，數據傳輸速率可設定為1200bps、2400bps和4800bps。在這三種波特率下，邏輯高、低電平的頻率相應為1200／1800Ｈｚ，1200／2400Ｈｚ，2400／4800Ｈｚ。CMX469A采用快速移頻鍵控FFSK／MSK調制方式，可廣泛應用于無線通訊系統中（例如水文檢測系統、船載監控系統等）

CMX469A特性：
●具有獨立的發送、接收使能控制；
●可以接外部１．008MHz或４．032MHz晶振;
●可選擇三種波特率：1200bps、2400bps、4800bps（4800bps傳輸時，需要外接4.032MHz晶振）；
●具有載波檢測、接收時鐘故障恢復功能；
●低電壓、低功耗（電源為3V時，典型工作電流為2mA；節能模式下，供電電流只有300μＡ）；
●抗干擾性能優良，在信號條件比較差的情況下具有優良的靈敏度，同時可通過外部電容設置載波檢測周期，以使器件在高噪音環境下具有更完善的性能。

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