MICRO-LINEAR ML2721

product
BRIEF
900MHz DSSS RF to Digital
Transceiver Chipset
All the BOM Advantages of Direct Conversion Radio
The Performance Advantages of a Superhet Radio
Small, Simple to Use and Ideal for Volume Manufacture
ML2721
Low IF Digital Cordless
Transceiver
ML2751
Power Amplifier and LNA
Features
ML2721
ML2751
Fully Integrated Receiver With 900mhz RF In
And NRZ Out
Power Amplifier Output +21dbm (125mw) Typical
Max Output At 3.0V
Fully Integrated Transmitter With Integrated
Modulation Filter
Power Amplifier Gain 35db (Typical Max)
Fully Integrated, Self Aligning IF Filtering,
Frequency To Voltage Converter, Transmit And
Receive Data Filters
Integrated Frequency Synthesizer With On
Chip Pre Aligned VCO
Single Supply 2.7V - 4.5V Operating Range
Power Amplifier Efficiency 35% At 3.3V
PA Control Pin For Power Consumption Reduction In
Portable Products
On-Chip Low Noise Amplifier For Receiver
•
Transmitter Low Voltage Lock-Out Circuit To Avoid
Out Of Band Emissions At Low Battery Voltage
On-Chip PIN Diode Drivers For Tx/Rx
•
•
•
On-Chip DC Regulation For 2.7V To 5.0V Operation
Small TSSOP-20 Package
Analog RSSI Output
Small 32 Pin TQFP Package, 0.75mm Pitch
900MHz DSSS RF to Digital Transceiver Chipset
Micro Linear has developed a single IC radio, the ML2721. The very high level of integration
absorbs all the circuits either difficult to design or those that require production alignment. Adding
just an external RF switch makes a complete radio with a digital control interface. On receive, the
input is RF, the output is demodulated data. All the LO circuits are integrated, including the VCO
tank circuit which Micro Linear tunes in production. For transmit, the chip is digital data in and
modulated RF out. To ensure proper functionality in products, all the DC regulation and power
management functions are integrated into the ML2721. This chip can be used for 900MHz ISM
band applications, as either a 1.1Mbps to 1.6Mbps FSK radio, or a 1.1Mcps direct sequence radio.
To extend the radio range, the ML2751 integrates a 100mW PA and a 18dB gain LNA. The ML2751
PA/LNA can implement front-end solutions for many communications products using TDD/TDMA
(half duplex radios) in the 600MHz to 1 GHz range and for transmitter powers up to 100mW at 3.0V.
Block Diagram
ML2751
ANTENNA
902 - 928
MHz FILTER
ML2731
IF CIRCUITS
LNA
BASEBAND
IC
MODEM
CODEC
PROTOCOL
MMI
CONTROL
FILTER
ALIGN
RF PIN
DIODE
SWITCH
WATCH
AND
OSCILLATOR
XTAL
CONTROL
LOGIC
PIN DIODE
DRIVERS
PLL
Tx RF
BUFFER
PA & DRIVER
QUADRATURE
DIVIDED BY 2
VTUNE
Tx DATA
FILTER
MEMORY
KEYPAD
DISPLAY
MIC
SPEAKER
RINGER
LOOP
FILTER
BATTERY
Micro Linear makes no representations or warranties with respect to the accuracy, utility, or completeness of the contents of this publication and reserves the right to make changes to specifications and product
descriptions at any time without notice. No license, express or implied, by estoppel or otherwise, to any patents or other intellectual property rights is granted by this document. The circuits contained in this
document are offered as possible applications only. Particular uses or applications may invalidate some of the specifications and/or product descriptions contained herein. The customer is urged to perform its
own engineering review before deciding on a particular application. Micro Linear assumes no liability whatsoever, and disclaims any express or implied warranty, relating to sale and/or use of Micro Linear
products including liability or warranties relating to merchantability, fitness for a particular purpose, or infringement of any intellectual property right. Micro Linear products are not designed for use in medical,
CORPORATE HEADQUARTERS
WESTERN UNITED STATES
Micro Linear Corporation
2092 Concourse Drive
San Jose, CA 95131
Tel: (408) 433-5200
Fax: (408) 432-1627
http//www.microlinear.com
CENTRAL UNITED STATES
Micro Linear Corporation
59 Cardinal Street
Pearl River, NY 10965
Tel: (914) 735-5848
Fax: (914) 735-5852
© 2000 Micro Linear Corporation. All Rights Reserved.
EASTERN UNITED STATES
Micro Linear Corporation
35 Pinehurst Avenue
Nashua, NH 03062
Tel: (603) 888-1326
Fax: (603) 888-4239
EUROPE
Micro Linear Corporation
Babraham Road
Sawston, Cambridge
CB2 4LJ, UK
Tel: 44-1223-839534
Fax: 44-1223-836761
ASIA
Micro Linear Corporation
#705 2-8-12 Mita
Minato-ku, Tokyo 108-0073
Tel/Fax: +81-3-5439-6256
10k
0200
PB2721-01