TLC7528C, TLC7528E, TLC7528I

DUAL 8BIT MULTIPLYING

DIGITALTOANALOG CONVERTERS

SLAS062E − JANUARY 1987 − REVISED NOVEMBER 2008

12

POST OFFICE BOX 655303

APPLICATION INFORMATION

Table 3. Attenuation vs DACA, DACB Code

ATTEN (dB)

DAC INPUT CODE

CODE IN

DECIMAL

ATTN (dB)

DAC INPUT CODE

CODE IN

DECIMAL

0

1 1 1 1 1 1 1 1

255

8.0

0 1 1 0 0 1 1 0

102

0.5

1 1 1 1 0 0 1 0

242

8.5

0 1 1 0 0 0 0 0

96

1.0

1 1 1 0 0 1 0 0

228

9.0

0 1 0 1 1 0 1 1

91

1.5

1 1 0 1 0 1 1 1

215

9.5

0 1 0 1 0 1 1 0

86

2.0

1 1 0 0 1 0 1 1

203

10.0

0 1 0 1 0 0 0 1

81

2.5

1 1 0 0 0 0 0 0

192

10.5

0 1 0 0 1 1 0 0

76

3.0

1 0 1 1 0 1 0 1

181

11.0

0 1 0 0 1 0 0 0

72

3.5

1 0 1 0 1 0 1 1

171

11.5

0 1 0 0 0 1 0 0

68

4.0

1 0 1 0 0 0 1 0

162

12.0

0 1 0 0 0 0 0 0

64

4.5

1 0 0 1 1 0 0 0

152

12.5

0 0 1 1 1 1 0 1

61

5.0

1 0 0 1 1 1 1 1

144

13.0

0 0 1 1 1 0 0 1

57

5.5

1 0 0 0 1 0 0 0

136

13.5

0 0 1 1 0 1 1 0

54

6.0

1 0 0 0 0 0 0 0

128

14.0

0 0 1 1 0 0 1 1

51

6.5

0 1 1 1 1 0 0 1

121

14.5

0 0 1 1 0 0 0 0

48

7.0

0 1 1 1 0 0 1 0

114

15.0

0 0 1 0 1 1 1 0

46

7.5

0 1 1 0 1 1 0 0

108

15.5

0 0 1 0 1 0 1 1

43

programmable state-variable filter

This programmable state-variable or universal filter configuration provides low-pass, high-pass, and bandpass

outputs, and is suitable for applications requiring microprocessor control of filter parameters.

As shown in Figure 10, DACA1 and DACB1 control the gain and Q of the filter while DACA2 and DACB2 control

the cutoff frequency. Both halves of the DACA2 and DACB2 must track accurately in order for the

cutoff-frequency equation to be true. With the TLC7528, this validity is easy to achieve.

fc +

1

2

p R1C1

The programmable range for the cutoff or center frequency is 0kHz to 15kHz with a Q ranging from 0.3 to 4.5.

This parameter defines the limits of the component values.