
6-57
6
M
Produc t Desc ription
Ordering Information
Typic al Applic ations
Features
Func tional 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 HBT
Si Bi-CMOS
SiGe HBT
GaAs MESFET
Si CMOS
1
2
3
4
8
7
6
5
IF+
IF-
GND
LO+
RF OUT
VCC
GND
LO-
RF9908
CDMA/FM UPCONVE R T E R/BPS K MODULAT OR
CDMA/FM Cellular Systems
Supports Dual-Mode AMPS/CDMA
Supports Dual-Mode TACS/CDMA
Commercial and Consumer Systems
3-Cell Battery-Operated Systems
The RF9908 is a complete upconverter designed for
CDMA/FM cellular applications. The IC contains a dou-
ble-balanced mixer stage and an output buffer amplifier
stage. This device may also be used to directly BPSK
modulate a carrier. The mixer is a Gilbert cell with emitter
degeneration resistors to provide high IP
3
. The output
stage is a class-B, push-pull configuration to reduce the
overall current and still provide a good 50
output match.
The unit operates at 3.6V and does not require any exter-
nal matching components other than coupling capacitors.
This circuit is designed as part of the RFMD CDMA Chip
Set, consisting of a Transmit IF AGC Amp, this Transmit
Upconverter, a Receive LNA/Mixer, and a Receive IF
AGC Amp.
Supports Dual Mode Operation
+8dBm Input/Output Intercept Point
Single 3.6V Power Supply
Internally Matched Inputs and Outputs
Buffered Output
Double-Balanced Mixer
RF9908
RF9908 PCBA
CDMA/FM Upconverter/BPSK Modulator
Fully Assembled Evaluation Board
6
Rev A2 010720
0.244
0.229
0.157
0.150
0.018
0.014
0.050
0.068
0.053
NOTES:
1. Shaded lead is Pin 1.
2. All dimensions are excluding
mold flash.
3. Lead coplanarity -
0.005 with respect to datum "A".
Dimensions in mm
0.196
0.189
0.008
0.004
-A-
8° MAX
0° MIN
0.034
0.016
0.009
0.007
Pac kage S tyle: S OIC-8