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PRISM™ 2.4GHz Chip Set
Direct Sequence Spread Spectrum
Wireless Transceiver Chip Set
The Intersil 2.4GHz PRISM™ chip set is
a highly integrated six-chip solution for
RF modems employing Direct Sequence
Spread Spectrum (DSSS) signaling.
Significant integration of tr ansmit and
receive functions employ the following ICs: complete integrated
DSSS engine, the HFA3824; a quadrature
modulator/demodulator, integrated with an IF limiter amplifier
with RSSI, the HFA3724, HFA3726; a combined LNA/Mix er
and upconv erter/preamplifier , the HFA3624; a high
perf ormance, low noise amplifier f or increased receiver
sensitivity, the HFA3424; a dual synthesizer, the HFA3524 and
a monolithic RF power amplifier, the HFA3925. Each of the
functions ma y be used individually or in any combination in
support of a v ariety of RF modem applications.
The PRISM™ chip set is intended to support various data
rates including systems targeting the proposed IEEE 802.11
standard “Direct Sequence Ph ysical layer (DS-PHY)”.
Diff erential BPSK and QPSK signaling is employed with
diff erential encoding and decoding of packetized data. A PN
sequence rate of up to 22 MCPS is supported f or up to a 16
chip PN code. Integr ated prog r ammable low pass filters are
used on the HFA3724 to allow chip rates from 2.75 MCPS to
22 MCPS. A flexible gener al purpose data and control
interf ace is pro vided for parameter configuration and for
transferring data packets between the PHY and Media Access
Control (MAC) layers. Data rates of up to 2 MBPS for DBPSK
and 4 MBPS f or DQPSK are supported.
Features
• Provides Antenna-to-Bits™ Data Stream
• Low Voltage Operation from 2.7V to 5.5V
• 2.4GHz - 2.5GHz ISM Band Operation
• Single Heterodyne Conversion
• Programmable Antialiasing and Shaping Filters
• 10MHz to 400MHz IF Operation with RSSI
• Autonomous Half Duplex Direct Sequence Modem
• Selectable DBPSK, DQPSK Signalling
• Antenna Diversity Selection
• Direct Sequence Physical Layer (DS-PHY)
• Differential Data Encoding/Decoding
• Programmable 16-Bit PN Code
• Data Rates up to 4 MBPS DQPSK
• Power Management Control
• Low Profile PCMCIA-Compatible Surface Mount
Packaging
Applications
• Systems Targeting IEEE 802.11 Standard
• PCMCIA Wireless Transceiver
• WLAN RF Modems
• TDMA Packet Protocol Radios
• Part 15 Compliant Radio Links
Typical Application Diagram
™
QUAD IF MODULATOR
RFPA
HFA3925
HFA3724, HFA3726
DSSS BASEBAND PROCESSOR
DATA TO MACCTRL
HFA3824
TUNE/SELECT
HFA3524/A
0o/90o
VCO
A/D
A/D
MAC-PHY
INTERFACE
802.11
VCO
DUAL SYNTHESIZER
HFA3624
UP/DOWN
CONVERTER A/D
(FILE# 4067, 4310) (FILE# 4308)
(FILE# 4062)
(FILE# 4066)
(FILE# 4132)
PRISM™ CHIP SET FILE #4063
M
U
X
M
U
X
DPSK
DEMOD
DPSK
MOD.
DE-
SPREAD
SPREAD
Q
I
HFA3424 (NOTE)
(FILE# 4131)
NOTE: Required for systems targeting 802.11 specifications.
CCA
RXI
RXQ
RSSI
TXI
TXQ
÷2
Data Sheet August 1997 File Number
4063.6
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
http://www.intersil.com or 407-727-9207 |Copyright © Intersil Corporation 1999
PRISM® is a registered trademark of Intersil Corporation. PRISM logo is a trademark of Intersil Corporation.
Antenna to Bits™ is a trademark of Intersil Corporation.
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All Intersil semiconductor products are manufactured, assembled and tested under ISO9000 quality systems certification.
Intersil semiconductor products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design and/or specifications at any time with-
out notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No license is gr anted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see web site http://www.intersil.com
Sales Office Headquarters
NORTH AMERICA
Intersil Corporation
P. O. Box 883, Mail Stop 53-204
Melbourne, FL 32902
TEL: (407) 724-7000
FAX: (407) 724-7240
EUROPE
Intersil SA
Mercure Center
100, Rue de la Fusee
1130 Brussels, Belgium
TEL: (32) 2.724.2111
FAX: (32) 2.724.22.05
ASIA
Intersil (Taiwan) Ltd.
7F-6, No. 101 Fu Hsing North Road
Taipei, Taiwan
Republic of China
TEL: (886) 2 2716 9310
FAX: (886) 2 2715 3029
Typical 802.11 DS-PHY System Level Performance
(Note 5) (Measured at a diversity antenna port)
Receiver
• Frequency Range . . . . . . . . . . . . . . .2.4GHz - 2.4835GHz
• Step Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1MHz
• Cascaded Noise Figure . . . . . . . . . . . . . . . . . . . . . .6.8dB
• Sensitivity . . . . . . . .-93dBm, 1 MBPS, 8E-2 FER (Note 1)
-90dBm, 2 MBPS, 8E-2 FER (Note 1)
• Input Intercept Point . . . . . . . . . . . . . . . . . . . . . . . -17dBm
• IF Frequency. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280MHz
• IF Bandwidth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17MHz
• Image Rejection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80dB
• Adjacent Channel Rejection . . . . . . . . . . . . . . . . . . >35dB
• Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . .2.7V - 5.5V
Transmitter
• Frequency Range . . . . . . . . . . . . . .2.4GHz - 2.4835GHz
• Step Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1MHz
• Output Power . . . . . . . . . . . . . . . . . . . . . . . . . . . .+18dBm
• Spurious Outputs . . . . . . . . . . . . . . Targeting ISM/802.11
• Transmit Spectral Mask . . . . . . -32dBr at First Side-Lobe
• IF Frequency. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280MHz
• Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . .2.7V - 5.5V
General Specifications
• Targeted Standard . . . . . . . . . . . . . . . . . . . . .IEEE 802.11
• Data Rate. . . . . . . . . . . . . . . . . . . . . . . . .1 MBPS DBPSK
2 MBPS DQPSK
• Range. . . . . . . . . . . . . . . . . . . . . . . . 400ft Indoor (Note 2)
3700ft Outdoor (Note 2)
• RX/TX Switching Speed. . . . . . . . . . . . . . . . . . . . . . . .2µs
• Power Savings Modes
- Mode 1: 190mA at 1µs Recovery (Notes 3, 4)
- Mode 2: 70mA at 25µs Recovery (Notes 3, 4)
- Mode 3: 60mA at 2ms Recovery (Notes 3, 4)
- Mode 4: 30mA at 5ms Recovery (Notes 3, 4)
• Average Current
(Without Power Savings Modes) . . . . . . . 298mA (Note 6)
• Average Current
(With Power Savings Modes) . . . . . . . . . . . 60mA (Note 7)
NOTES:
1. FER = Frame Error Rate or Packet Error Rate.
2. Range Test using AND-C-107 omnidirectional antenna.
3. Supply current includes AM79C930 MAC Processor.
4. Recovery time is for the PRISM™ 2.4GHz Chip Set only and
does not include programming latency of the AM79C930 MAC
Processor.
5. Refer to Application Note AN9624 for more information on the
“PRISM™ DSSS PC Card Wireless LAN Description”.
6. Based on average current consumption for “typical” application.
7. Power savings modes refer to AN9665. Average radio current
consumption for “typical” application.
PRISM™ 2.4GHz Chip Set
