Datasheet

+
+
+
–
I
Q
DAC
DAC
A
B
LO
Quadrature
Modulator
DAC5686
cos(w
c
t)
sin(w
c
t)
sin(w
c
t)
cos(w
c
t)
A(t) = I(t)cos(w w
c c
t) – Q(t)sin( t)
B(t) = I(t)sin(w w
c c
t) + Q(t)cos( t)
cos(w
LO
t)
sin(w
LO
t)
0°
90°
IF(t) = I(t)cos(w w
w w
c LO
c LO
+ )t
– Q(t)sin( + )t
B0022–01
0
0
ω
c
ω
ω
ω
ω
LO
ω
LO
– ω
c
ω
LO
+ ω
c
Real Input
Spectrum
to DAC5686
Complex Input
Spectrum
to Quadrature Modulator
Output Spectrum
to Quadrature Modulator
M0016-01
DAC5686
www.ti.com ............................................................................................................................................................ SLWS147F – APRIL 2003 – REVISED JUNE 2009
Figure 20. DAC5686 in SSB Mode With Quadrature Modulator
Figure 21. Spectrum After First and Second Up-Converson for Real Input
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