DAC1617D1G0HN IDT [Integrated Device Technology], DAC1617D1G0HN Datasheet - Page 30

• Manufacturer Part Number: DAC1617D1G0HN
• Description: Dual 16-bit DAC, LVDS interface, up to 1 Gsps, x2, x4 and x8 interpolating
• Manufacturer: IDT [Integrated Device Technology]

Integrated Device Technology
Table 15.
DAC1617D1G0 3
Preliminary data sheet
MODULATION[2:0] Mode
000
001
010
011
100
others
Complex modulator operation mode
10.11.2 NCO low power
10.11.3 Complex modulator
bypass
positive
upper sob
positive
lower ssb
negative
upper ssb
negative
lower ssb
not defined
The five MSB-bits of register FREQNCO_B4 (bits FREQ_NCO[39:35]; see Table 25) can
set the frequency, when using NCO low power (bit NCO_LP_SEL; see Table 23).
The frequency is calculated with Equation 5.
Where:
The five MSB-bits of register PHINCO_MSB (see Table 31) can set the phase of the NCO
low power.
The complex modulator upconverts the single side band by mixing NCO signals and I and
Q input signals. Table 15 shows the various possibilities set by bits MODULATION[2:0] of
register TXCFG (see Table 23).
The effect of the MODULATION parameter is better viewed after mixing the A and B
signal with a LO frequency through an IQ modulator:
Fig 21. Complex modulation after LO mixing
•
•
f
NCO
M is the two’s complement coding representation of FREQ_NCO[39:35]
f
s
is the DAC clock sampling frequency
=
M
--------------
Path A
-
I t  
I t  
I t  
I t  
2

5




f
s
cos
cos
cos
cos








NCO
NCO
NCO
NCO
Rev. 03 — 2 July 2012




t
t
t
t




I t  
Dual 16-bit DAC: up to 1 Gsps; x2, x4 and x8 interpolating
–
+
–
+
Q t  
Q t  
Q t  
Q t  




sin
sin
sin
sin








NCO
NCO
NCO
NCO




t
t
t
t




Path B
-
I t  
I t  
–
–
I t  
I t  




sin
sin
sin
sin


DAC1617D1G0






NCO
NCO
NCO
NCO




t
t


t
t
Q t  
+
–


–
+
Q t  
Q t  
Q t  
Q t  


© IDT 2012. All rights reserved.


cos
cos
cos
cos








NCO
NCO
NCO
NCO
30 of 78




t
t

(5)

t
t

