RF9908
6
Typical Applications
鈥?CDMA/FM Cellular Systems
鈥?Supports Dual-Mode AMPS/CDMA
鈥?Supports Dual-Mode TACS/CDMA
鈥?Commercial and Consumer Systems
鈥?3-Cell Battery-Operated Systems
CDMA/FM UPCONVERTER/BPSK MODULATOR
Product Description
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鈩?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.
Optimum Technology Matching廬 Applied
Si BJT
Si Bi-CMOS
0.008
0.004
0.018
0.014
-A-
0.196
0.189
0.050
6
0.157
0.150
0.244
0.229
Dimensions in mm
0.068
0.053
8擄 MAX
0擄 MIN
0.034
0.016
0.009
0.007
NOTES:
1. Shaded lead is Pin 1.
2. All dimensions are excluding
mold flash.
3. Lead coplanarity -
0.005 with respect to datum "A".
眉
GaAs HBT
SiGe HBT
Package Style: SOIC-8
GaAs MESFET
Si CMOS
Features
鈥?Supports Dual Mode Operation
鈥?+8dBm Input/Output Intercept Point
鈥?Single 3.6V Power Supply
鈥?Internally Matched Inputs and Outputs
鈥?Buffered Output
鈥?Double-Balanced Mixer
IF+ 1
IF- 2
GND 3
LO+ 4
8 RF OUT
7 VCC
6 GND
5 LO-
Ordering Information
RF9908
RF9908 PCBA
CDMA/FM Upconverter/BPSK Modulator
Fully Assembled Evaluation Board
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
Rev A2 010720
6-57
MIXERS
1
2
3
4
