Datasheet

AD9786
Rev. B | Page 26 of 56
DIGITAL FILTER SPECIFICATIONS
DIGITAL INTERPOLATION FILTER COEFFICIENTS
Table 23. Stage 1 Interpolation Filter Coefficients
Lower Coefficient Upper Coefficient Integer Value
H(1) H(43) 9
H(2) H(42) 0
H(3) H(41) –27
H(4) H(40) 0
H(5) H(39) 65
H(6) H(38) 0
H(7) H(37) –131
H(8) H(36) 0
H(9) H(35) 239
H(10) H(34) 0
H(11) H(33) –407
H(12) H(32) 0
H(13) H(31) 665
H(14) H(30) 0
H(15) H(29) –1070
H(16) H(28) 0
H(17) H(27) 1764
H(18) H(26) 0
H(19) H(25) –3273
H(20) H(24) 0
H(21) H(23) 10358
H(22) 16384
Table 24. Stage 2 Interpolation Filter Coefficients
Lower Coefficient Upper Coefficient Integer Value
H(1) H(19) 19
H(2) H(18) 0
H(3) H(17) –120
H(4) H(16) 0
H(5) H(15) 436
H(6) H(14) 0
H(7) H(13) –1284
H(8) H(12) 0
H(9) H(11) 5045
H(10) 8192
Table 25. Stage 3 Interpolation Filter Coefficients
Lower Coefficient Upper Coefficient Integer Value
H(1) H(11) 7
H(2) H(10) 0
H(3) H(9) –53
H(4) H(8) 0
H(5) H(7) 302
H(6) 512
03152-041
0.5–0.5 –0.4 –0.3 –0.2 –0.1 0 0.1 0.2 0.3 0.4
–
140
0
–20
–40
–60
–80
–
100
–
120
Figure 41. 2× Interpolation Filter Response
03152-042
0.5–0.5 –0.4 –0.3 –0.2 –0.1 0 0.1 0.2 0.3 0.4
–
140
0
–20
–40
–60
–80
–
100
–
120
Figure 42. 4× Interpolation Filter Response
03152-043 0.5–0.5 –0.4 –0.3 –0.2 –0.1 0 0.1 0.2 0.3 0.4
–
140
0
–20
–40
–60
–80
–
100
–
120
Figure 43. 8× Interpolation Filter Response