PRISM 2.4GHz Chip Set - Intersil Corporation

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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

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

DPSK

DEMOD

DPSK

MOD.

DE-

SPREAD

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.

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