Datasheet
AD9260
Rev. C | Page 8 of 44
Table 5. Integer Filter Coefficients for First Stage
Decimation Filter (23-Tap Half-Band FIR Filter)
Lower Coefficient Upper Coefficient Integer Value
H(1) H(23) –1
H(2) H(22) 0
H(3) H(21) 13
H(4) H(20) 0
H(5) H(19) –66
H(6) H(18) 0
H(7) H(17) 224
H(8) H(16) 0
H(9) H(15) –642
H(10) H(14) 0
H(11) H(13) 2496
H(12) 4048
Table 6. Integer Filter Coefficients for Second Stage
Decimation Filter (43-Tap Half-Band FIR Filter)
Lower Coefficient Upper Coefficient Integer Value
H(1) H(43) 3
H(2) H(42) 0
H(3) H(41) –12
H(4) H(40) 0
H(5) H(39) 35
H(6) H(38) 0
H(7) H(37) –83
H(8) H(36) 0
H(9) H(35) 172
H(10) H(34) 0
H(11) H(33) –324
H(12) H(32) 0
H(13) H(31) 572
H(14) H(30) 0
H(15) H(29) –976
H(16) H(28) 0
H(17) H(27) 1680
H(18) H(26) 0
H(19) H(25) –3204
H(20) H(24) 0
H(21) H(23) 10274
H(22) 16274
NOTE: The composite filter undecimated coefficients (i.e.,
impulse response) in the 4× decimation mode can be
determined by convolving the first stage filter taps with a
“zero stuffed” version of the second stage filter taps (i.e., insert
one zero between samples). Similarly, the composite filter
coefficients in the 8× decimation mode can be determined by
convolving the taps of the composite 4× decimation mode (as
previously determined) with a “zero stuffed” version of the third
stage filter taps (i.e., insert three zeros between samples).
Table 7. Integer Filter Coefficients for Third Stage
Decimation Filter (107-Tap Half-Band FIR Filter)
Lower Coefficient Upper Coefficient Integer Value
H(1) H(107) –1
H(2) H(106) 0
H(3) H(105) 2
H(4) H(104) 0
H(5) H(103) –2
H(6) H(102) 0
H(7) H(101) 3
H(8) H(100) 0
H(9) H(99) –3
H(10) H(98) 0
H(11) H(97) 1
H(12) H(96) 0
H(13) H(95) 3
H(14) H(94) 0
H(15) H(93) –12
H(16) H(92) 0
H(17) H(91) 27
H(18) H(90) 0
H(19) H(89) –50
H(20) H(88) 0
H(21) H(87) 85
H(22) H(86) 0
H(23) H(85) –135
H(24) H(84) 0
H(25) H(83) 204
H(26) H(82) 0
H(27) H(81) –297
H(28) H(80) 0
H(29) H(79) 420
H(30) H(78) 0
H(31) H(77) –579
H(32) H(76) 0
H(33) H(75) 784
H(34) H(74) 0
H(35) H(73) –1044
H(36) H(72) 0
H(37) H(71) 1376
H(38) H(70) 0
H(39) H(69) –1797
H(40) H(68) 0
H(41) H(67) 2344
H(42) H(66) 0
H(43) H(65) –3072
H(44) H(64) 0
H(45) H(63) 4089
H(46) H(62) 0
H(47) H(61) –5624
H(48) H(60) 0
H(49) H(59) 8280
H(50) H(58) 0
H(51) H(57) –14268
H(52) H(56) 0
H(53) H(55) 43520
H(54) 68508