Analog Devices AD9854 User Manual

AD9854
Rev. E | Page 16 of 52
TYPICAL APPLICATIONS
LPF
REFCLK
RF/IF
INPUT
I BASEBAND
COS
LPF
LPF
AD9854
Q BASEBAND
LPF
SIN
00636-025
CHANNEL
SELECT
FILTERS
Figure 25. Quadrature Downconversion
LPF
REFCLK
COS
LPF
AD9854
SIN
RF OUTPUT
I BASEBAND
Q BASEBAND
00636-026
Figure 26. Direct Conversion Quadrature Upconverter
I
Q
Rx
RF IN
DUAL
8-/10-BIT
ADC
DIGITAL
DEMODULATOR
Rx BASEBAND
DIGITAL DATA
OUT
8
8
I/Q MIXER
AND
LOW-PASS
FILTER
VCA
ADC ENCODE
ADC CLOCK FREQUENCY
LOCKED TO Tx CHIP/
SYMBOL/PN RATE
REFERENCE
CLOCK
48
CHIP/SYMBOL/PN
RATE DATA
AD9854
CLOCK
GENERATOR
AGC
00636-027
Figure 27. Chip Rate Generator in Spread Spectrum Application
50 Ω
BAND-P
A
SS
FILTER
50Ω
I
OUT
AD9854
FUNDAMENTAL
F
C
–F
O
IMAGE
F
CLK
F
C
+F
O
IMAGE
BAND-PASS
FILTER
F
C
+F
O
IMAGE
AD9854
SPECTRUM
FINAL OUTPUT
SPECTRUM
AMPLIFIER
00636-028
Figure 28. Using an Aliased Image to Generate a High Frequency

Analog Devices AD9854 Specifications

General

Brand	Analog Devices
Model	AD9854
Category	Synthesizer
Language	English