AD8345_15 Datasheet, PDF (1/20 Pages) Analog Devices – 140 MHz to 1000 MHz Quadrature Modulator

FEATURES
140 MHz to 1000 MHz operating frequency
+2.5 dBm P1dB @ 800 MHz
−155 dBm/Hz noise floor
0.5 degree RMS phase error (IS95)
0.2 dB amplitude balance
Single 2.7 V to 5.5 V supply
Pin-compatible with AD8346 and AD8349
16-lead TSSOP_EP 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
PRODUCT DESCRIPTION
The AD8345 is a silicon RFIC quadrature modulator, designed
for use from 140 MHz to 1000 MHz. Its excellent phase
accuracy 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 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.
140 MHz to 1000 MHz
Quadrature Modulator
AD8345
FUNCTIONAL BLOCK DIAGRAM
IBBP 1
AD8345
16 QBBP
IBBN 2
15 QBBN
COM3 3
COM1 ⁴
14 COM3
+
13 COM3
LOIN 5
LOIP 6
VPS1 7
ENBL 8
PHASE
SPLITTER
BIAS
12 VPS2
11 VOUT
10 COM2
9 COM3
Figure 1.
APPLICATIONS
The AD8345 modulator can be used as the IF transmit
modulator 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
communication 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_EP
package. 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. B
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