Datasheet

  
  
 
SLAS062E − JANUARY 1987 − REVISED NOVEMBER 2008
12
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
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.
f
c
+
1
2p 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.