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PRODUCT INFORMATION

CML Semiconductor Products

FX589

Features

Full-Duplex Gaussian Minimum

Shift Keying (GMSK)

Operating from 3 Volts to 5.5 Volts

Data Rates 4kb/s to 64kb/s

Selectable BT (0.3 or 0.5)

Low-Current Analogue/Digital

Non-DSP Solution

Meets RCR STD-18

Applications

Wireless LAN/Modems

Handy Data Terminals

Low-Power Wireless Data Link

for PCs, Laptops and Printers

Point-Of-Sale Terminals

Wireless Bar-Code Readers

and Stock Controllers

Brief Description

The FX589 is a single-chip modem employing

Gaussian Minimum Shift Keying (GMSK) modulation.

Data rates of 4kb/s to 64kb/s and the choice of BT

to 0.3 or 0.5 are pin-programmable functions to suit

radio data channel bandwidth requirements.

The Rx and Tx digital data interfaces are bit-serial

and synchronised to Rx and Tx data clocks generated

by the modem. Separate Rx and Tx Powersave/Enable

inputs allow for full- or half-duplex operation.

Rx input levels can be set by a suitable ac and dc

level adjusting circuit built, with external components,

around an on-chip Rx input amplifier.

FX589

Tx PS

Rx PS

BT

Tx DATA

ClkDIVA

PLLacq

RxDCacq

Rx SIGNAL IN

Rx FEEDBACK

ClkDIVB

XTAL/CLOCK

Tx ENABLE

XTAL

RxHold

+

-

DOC1

Rx CLOCK

Tx CLOCK

Tx OUT

Rx DATA

Rx S/N

DOC2

DATA RETIME

&

LEVEL SHIFT

Tx

FILTER

CLOCK

DIVIDER

Rx CIRCUIT

CONTROL

Rx

FILTER

Rx LEVEL

MEASURE

Rx CLOCK

EXTRACT

Rx S/N

DETECTION

Rx DATA

EXTRACT

Low-Voltage/High-Speed

GMSK Modem

Fig.1 Functional Block Diagram

Acquisition, lock and hold of Rx data signals is made

easier and faster by the use of Rx Control Inputs to clamp,

detect and/or hold input data levels and can be set by the

system µProcessor as required.

Indication is available, from the Rx S/N output, as to the

quality of the received signal.

The FX589 design features a low-current analogue/digital

ASIC process offering significantly lower current

consumption than DSP technology. For data rates up to

32kb/s the FX589 draws typically 1.5mA at 3.0 volts V

for data rates up to 64kb/s at 5.0 volts, typically 4.0mA.

This low-power CMOS microcircuit is available in both

24-pin plastic DIL and Small Outline (SOIC and SSOP)

packages.

Publication D/589/7 January 1998