
2-27
7
Preliminary
Product Description
Ordering Information
Typical Applications
Features
Functional Block Diagram
RF Micro Devices, Inc.
7628 Thorndike Road
Greensboro, NC 27409, USA
Tel (336) 664 1233
Fax (336) 664 0454
http://www.rfmd.com
Optimum Technology Matching® Applied
Si BJT
GaAs MESFET
GaAs HBT
Si Bi-CMOS
ü
SiGe HBT
Si CMOS
1
2
3
4
5
6
7
14
13
12
11
10
9
8
IF1+
GND
OSCB
OSCE
GND
LO2-
LO2+
IF IN-
VCC
PD
GND
I OUT
REF IN
Q OUT
QUAD
DIV.
BY 2
POWER
CONTROL
5k
Ω
5k
Ω
RF2721
QUADRATURE DEMODULATOR
• UHF Digital and Analog Receivers
• Digital Communication Systems
• Spread-Spectrum Communication Systems
• Commercial and Consumer Systems
• Portable Battery-Powered Equipment
• General Purpose Frequency Conversion
The RF2721 is a monolithic integrated quadrature
demodulator intended for use in digital mobile radio
receivers. In this application it is used to recover the in-
phase and quadrature baseband signals from the ampli-
fied and filtered IF. The RF2721 is intended for IF sys-
tems where the IF frequency ranges from 100kHz to
500MHz, and the LO frequency is two times the IF. The
IC contains all of the required components to implement
the demodulation function of the receiver and contains a
digital divider type 90° phase shifter, two double-balanced
mixers, and baseband amplifiers designed to interface
with analog to digital converters. The output DC offset
maybeslavedtothe referenceofthe ADCs to maintain
DC accuracy.
• 5V Power Supply
• On-Chip Active Device for Oscillator
• ADC Compatible Outputs
• Low LO Power Requirement
• Digitally Controlled Power Down Mode
• 100kHz to 500MHz IF Operation
RF2721
Quadrature Demodulator
RF2721 PCBA
Fully Assembled Evaluation Board
2
Rev A2 010509
0.156
0.148
0.059
0.057
0.252
0.236
0.010
0.004
.018
.014
8° MAX
0° MIN
0.0500
0.0164
0.010
0.007
0.347
0.339
0.050
Package Style: SOIC-14