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a

AD6411

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781/329-4700

World Wide Web Site: http://www.analog.com

Fax: 781/326-8703

© Analog Devices, Inc., 1998

DECT RF Transceiver

FUNCTIONAL BLOCK DIAGRAM

LNA

PA

RSSI

RX

DATA

TX

DATA

AD6411

PLL

DEMODULATOR

PLL

VCO

CONTROL

INTERFACE

PFD

FEATURES

Fully Compliant with DECT Specifications

Single IC DECT Radio

Integrated UHF VCO (External Resonator)

Integrated Synthesizer Supporting Extended Frequency

Allocation

Built-In Supply Regulation

Direct VCO Modulation for DECT Transmit Path

PLL-Based Demodulator

Use with Low Cost Plastic Packaged SAW Filters

Ultralow Power Design

Operates from +3.0 V to +5.5 V Battery

User-Selectable Power-Down Modes

Small 48-Lead LQFP Package

APPLICATIONS

DECT Cordless Telephones

DECT-Based Wireless Local Loop Systems

DECT-Based Wireless Data Systems

DESCRIPTION

The AD6411 provides the complete transmit and receive RF

signal processing necessary to implement a digital wireless

transceiver based on the Digital Enhanced Cordless Telecom-

munications (DECT) standard.

The AD6411’s receive signal path consists of a mixer, IF ampli-

fiers and PLL demodulator. The low noise, high intercept mixer

is a development of the doubly-balanced Gilbert-Cell type. It

has a nominal –16 dBm input-referred 1 dB compression point

and a –8 dBm input referred third-order intercept. The limiter

amplifier provides sufficient gain to drive the PLL demodulator,

which provides selectable analog or sliced outputs. The RSSI

output provides a voltage proportional to the receive signal

strength. It measures nearly 100 dB IF signal strength range

with 14 mV/dB gain scaling.

The transmit path accepts baseband data, which is filtered and

applied to the VCO directly. The VCO operates at half the RF

carrier frequency, and is doubled to avoid pulling due to leakage

from the output.

An on-chip PLL frequency synthesizer provides channel selec-

tion. Operating modes are selected either through a serial bus or

asynchronous control pins. This allows compatibility with most

of the available DECT baseband controller ASICs.

The AD6411 is packaged in a 48-lead LQFP.