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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.