AD9779A-EBZ Analog Devices Inc, AD9779A-EBZ Datasheet - Page 31

• Manufacturer Part Number: AD9779A-EBZ
• Description: Dual 16B, 1.0 GSPS TxDAC
• Manufacturer: Analog Devices Inc
• Series: TxDAC®r

Specifications of AD9779A-EBZ

• Design Resources: Interfacing ADL5370 to AD9779A Dual-Channel, 1 GSPS High Speed DAC (CN0016) Interfacing ADL5371 to AD9779A Dual-Channel, 1 GSPS High Speed DAC (CN0017) Interfacing ADL5372 to AD9779A Dual-Channel, 1 GSPS High Speed DAC (CN0018) Interfacing ADL5373 to AD9779A Dual-Channel, 1 GSPS High Speed DAC (CN0019) Interfacing ADL5374 to AD9779A Dual-Channel, 1 GSPS High Speed DAC (CN0020) Interfacing ADL5375 to AD9779A Dual-Channel, 1 GSPS High Speed DAC (CN0021)
• Number Of Dac's: 2
• Number Of Bits: 16
• Outputs And Type: 2, Differential
• Sampling Rate (per Second): 1G
• Data Interface: Serial
• Dac Type: Current
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Utilized Ic / Part: AD9779A
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Settling Time: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

INTERPOLATION FILTER ARCHITECTURE
The AD9776A/AD9778A/AD9779A can provide up to 8× inter-
polation, or the interpolation filters can be entirely disabled. It
is important to note that the input signal should be backed off
by approximately 0.01 dB from full scale to avoid overflowing
the interpolation filters. The coefficients of the low-pass filters
and the inverse sinc filter are given in Table 15, Table 16, Table 17,
and Table 18. Spectral plots for the filter responses are shown in
Figure 57, Figure 58, and Figure 59.
Table 15. Low-Pass Filter 1
Lower Coefficient
H(1)
H(2)
H(3)
H(4)
H(5)
H(6)
H(7)
H(8)
H(9)
H(10)
H(11)
H(12)
H(13)
H(14)
H(15)
H(16)
H(17)
H(18)
H(19)
H(20)
H(21)
H(22)
H(23)
H(24)
H(25)
H(26)
H(27)
H(28)
Upper Coefficient
H(55)
H(54)
H(53)
H(52)
H(51)
H(50)
H(49)
H(48)
H(47)
H(46)
H(45)
H(44)
H(43)
H(42)
H(41)
H(40)
H(39)
H(38)
H(37)
H(36)
H(35)
H(34)
H(33)
H(32)
H(31)
H(30)
H(29)
Integer Value
−4
0
+13
0
−34
0
+72
0
−138
0
+245
0
−408
0
+650
0
−1003
0
+1521
0
−2315
0
+3671
0
−6642
0
+20,755
+32,768
Rev. A | Page 31 of 60
Table 16. Low-Pass Filter 2
Lower Coefficient
H(1)
H(2)
H(3)
H(4)
H(5)
H(6)
H(7)
H(8)
H(9)
H(10)
H(11)
H(12)
Table 17. Low-Pass Filter 3
Lower Coefficient
H(1)
H(2)
H(3)
H(4)
H(5)
H(6)
H(7)
H(8)
Table 18. Inverse Sinc Filter
Lower Coefficient
H(1)
H(2)
H(3)
H(4)
H(5)
Figure 57. 2× Interpolation, Low-Pass Response to ±4× Input Data Rate
–100
–10
–20
–30
–40
–50
–60
–70
–80
–90
10
0
–4
–3
(Dotted Lines Indicate 1 dB Roll-Off)
AD9776A/AD9778A/AD9779A
–2
Upper Coefficient
H(15)
H(14)
H(13)
H(12)
H(11)
H(10)
H(9)
Upper Coefficient
H(9)
H(8)
H(7)
H(6)
Upper Coefficient
H(23)
H(22)
H(21)
H(20)
H(19)
H(18)
H(17)
H(16)
H(15)
H(14)
H(13)
f
OUT
–1
(× Input Data Rate)
0
1
Integer Value
−39
0
+273
0
−1102
0
+4964
+8192
Integer Value
+2
−4
+10
−35
+401
2
Integer Value
−2
0
+17
0
−75
0
+238
0
−660
0
+2530
+4096
3
4