a
FEATURES
250 MHz–1000 MHz Operating Frequency
+2.5 dBm P1 dB @ 800 MHz
–155 dBm/Hz Noise Floor
0.5 Degree RMS Phase Error (IS95)
0.2 dB Amplitude Balance
Single 2.7 V–5.5 V Supply
Pin-Compatible with AD8346
16-Lead Exposed Paddle TSSOP Package
APPLICATIONS
Cellular Communication Systems
W-CDMA/CDMA/GSM/PCS/ISM Transceivers
Fixed Broadband Access Systems LMDS/MMDS
Wireless LAN
Wireless Local Loop
Digital TV/CATV Modulators
Single Sideband Upconverter
250 MHz–1000 MHz
Quadrature Modulator
AD8345
FUNCTIONAL BLOCK DIAGRAM
AD8345
IBBP
1
IBBN
2
COM3
3
COM1
4
LOIN
5
LOIP
6
VPS1
7
BIAS
ENBL
8
9
COM3
16
QBBP
15
QBBN
14
COM3
13
COM3
12
VPS2
+
PHASE
SPLITTER
11
VOUT
10
COM2
PRODUCT DESCRIPTION
APPLICATIONS
The AD8345 is a silicon RFIC quadrature modulator, designed
for use from 250 MHz to 1000 MHz. Its excellent phase accu-
racy and amplitude balance enable the high performance direct
modulation of an IF carrier.
The AD8345 accurately splits the external LO signal into two
quadrature components through the polyphase phase-splitter
network. The two I and Q LO components are mixed with the
baseband I and Q differential input signals. Finally, the outputs
of the two mixers are combined in the output stage to provide a
single-ended 50
Ω
drive at VOUT.
The AD8345 Modulator can be used as the IF transmit modu-
lator in digital communication systems such as GSM and PCS
transceivers. It can also directly modulate an LO signal to
produce QPSK and various QAM formats for 900 MHz com-
munication systems as well as digital TV and CATV systems.
Additionally, this quadrature modulator can be used with direct
digital synthesizers in hybrid phase-locked loops to generate
signals over a wide frequency range with millihertz resolution.
The AD8345 Modulator is supplied in a 16-lead TSSOP pack-
age with exposed paddle. Its performance is specified over a
–40°C to +85°C temperature range. This device is fabricated on
Analog Devices’ advanced silicon bipolar process.
REV. 0
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 2001
AD [ ANALOG DEVICES ]
