AD9772A
DIGITAL FILTER SPECIFICATIONS
TMIN to TMAX, AVDD = 3.3 V, CLKVDD = 3.3 V, PLLVDD = 0 V, DVDD = 3.3 V, IOUTFS = 20 mA, differential transformer-coupled output,
50 Ω doubly terminated, unless otherwise noted.
Table 4.
Parameter
Min
Typ
Max
Unit
MAXIMUM INPUT DATA RATE (fDATA
DIGITAL FILTER CHARACTERISTICS
Pass-Bandwidth1: 0.00ꢀ dB
Pass-Bandwidth: 0.01 dB
Pass-Bandwidth: 0.1 dB
Pass-Bandwidth: −3 dB
)
1ꢀ0
MSPS
0.401
0.404
0.422
0.479
fOUT/fDATA
fOUT/fDATA
fOUT/fDATA
fOUT/fDATA
LINEAR PHASE (FIR IMPLEMENTATION)
STOP BAND REJECTION
0.606 fCLOCK to 1.394 fCLOCK
GROUP DELAY2
73
11
dB
Input clocks
IMPULSE RESPONSE DURATION
−40 dB
−60 dB
36
42
Input clocks
Input clocks
1 Excludes sin(x)/x characteristic of DAC.
2 Defined as the number of data clock cycles between impulse input and peak of output response.
0
Table 5. Integer Filter Coefficients for Interpolation Filter
(43-Tap Half-Band FIR Filter)
–20
–40
Lower
Upper
Coefficient
Integer
Value
Coefficient
H(1)
H(2)
H(3)
H(4)
H(ꢀ)
H(6)
H(7)
H(8)
H(43)
H(42)
H(41)
H(40)
H(39)
H(38)
H(37)
H(36)
H(3ꢀ)
H(34)
H(33)
H(32)
H(31)
H(30)
H(29)
H(28)
H(27)
H(26)
H(2ꢀ)
H(24)
H(23)
10
0
−31
0
69
–60
–80
–100
–120
–140
0
−138
0
248
0
−419
0
678
0
−1083
0
1776
0
−3282
0
10,364
16,384
H(9)
0
0.1 0.2
0.3 0.4
0.5 0.6
0.7
)
0.8
0.9 1.0
FREQUENCY (DC TO fDATA
H(10)
H(11)
H(12)
H(13)
H(14)
H(1ꢀ)
H(16)
H(17)
H(18)
H(19)
H(20)
H(21)
H(22)
Figure 4. FIR Filter Frequency Response—Baseband Mode
1.0
0.8
0.6
0.4
0.2
0
–0.2
–0.4
0
5
10
15
20
25
30
35
40
45
TIME (Samples)
Figure 5. FIR Filter Impulse Response—Baseband Mode
Rev. C | Page 8 of 40
ROCHESTER [ Rochester Electronics ]
