10

Maxim Integrated

Digitally-Programmed, Dual

2nd-Order Continuous Lowpass Filter

MAX270/MAX271

Table 1. Programmed Cutoff Frequency Codes (typ)

Programmed code is the data on pins D0–D6 (0–127). D6 is the MSB.

PROGRAMMED

CODE

fC (kHz)

PROGRAMMED

CODE

fC (kHz)

PROGRAMMED

CODE

fC

(kHz)

PROGRAMMED

CODE

fC (kHz)

0

1.000

32

1.576

64

3.571

96

6.325

1

1.011

33

1.605

65

3.620

97

6.481

2

1.023

34

1.635

66

3.671

98

6.645

3

1.035

35

1.666

67

3.723

99

6.818

4

1.047

36

1.699

68

3.777

100

7.008

5

1.060

37

1.732

69

3.832

101

7.191

6

1.073

38

1.767

70

3.888

102

7.394

7

1.087

39

1.804

71

3.947

103

7.608

8

1.100

40

1.842

72

4.007

104

7.835

9

1.114

41

1.881

73

4.069

105

8.076

10

1.129

42

1.923

74

4.133

106

8.333

11

1.143

43

1.966

75

4.200

107

8.606

12

1.158

44

2.011

76

4.268

108

8.898

13

1.174

45

2.058

77

4.338

109

9.210

14

1.190

46

2.108

78

4.411

110

9.545

15

1.206

47

2.160

79

4.487

111

9.905

16

1.223

48

2.215

80

4.565

112

10.294

17

1.241

49

2.272

81

4.646

113

10.714

18

11.259

50

2.333

82

4.729

114

11.170

19

1.277

51

2.397

83

4.816

115

11.666

20

1.296

52

2.464

84

4.906

116

12.209

21

1.315

53

2.536

85

5.000

117

12.804

22

1.335

54

2.611

86

5.097

118

13.461

23

1.356

55

2.692

87

5.198

119

14.189

24

1.378

56

2.777

88

5.303

120

15.000

25

1.400

57

2.868

89

5.412

121

15.909

26

1.422

58

2.966

90

5.526

122

16.935

27

1.446

59

3.070

91

5.645

123

18.103

28

1.470

60

3.181

92

5.769

124

19.444

29

1.495

61

3.301

93

5.898

125

21.000

30

1.521

62

3.431

94

6.034

126

22.826

31

1.548

63

3.571

95

6.176

127

25.000