FX469 查看數據表（PDF） - CML Microsystems Plc

零件编号

产品描述 (功能)

生产厂家

FX469

1200/2400/4800 Baud FFSK Modem

CML Microsystems Plc 

CML Semiconductor Products

PRODUCT INFORMATION

FX469 1200/2400/4800 Baud

FFSK Modem

Features

Selectable Data Rates

1200, 2400 and 4800 Baud

Full-Duplex FFSK

Rx and Tx Bandpass Filters

Clock Recovery and Carrier

Detect Facilities

Rx and Tx Enable Functions

Publication D/469/6 April 1998

Pin Selected Xtal/Clock Inputs

1.008MHz or 4.032MHz

Radio and General Applications

Data-Over-Radio

PMR and Cellular Signalling

Portable Data Terminals

Personal/Cordless Telephone

Tx DATA I/P

Tx ENABLE

Tx GENERATOR Tx FILTER

CLOCK RATE

XTAL/CLOCK

XTAL

CLOCK

OSCILLATOR

1200/2400 BAUD SELECT

4800 BAUD SELECT

Rx ENABLE

Rx SIGNAL I/P

Rx FILTER

DIVIDER

f .. n

LIMITER

RETRIGGERABLE

MONOSTABLE

DIGITAL

FILTER

DATA

FILTER

Tx SIGNAL O/P

Tx SYNC O/P

VDD

V BIAS

VSS

LIMITER

BANDPASS O/P

UNCLOCKED

DATA O/P

RECTIFIER

NOISE FILTER RECTIFIER

Fig.1 Functional Block Diagram

DIGITAL

PLL

DATA

LATCH

CLOCKED

DATA O/P

Rx SYNC O/P

S/N

COMPARATOR

CARRIER DETECT TIME CONSTANT

CARRIER DETECT O/P

FX469

Brief Description

The FX469 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 2400/4800

Hz 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

synchronization, the transmitter and receiver operate

entirely independently including individual section

powersave functions.

The FX469 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 FX469 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

(S.O.I.C) and cerdip DIL packages.

1

Share Link: