TLC7528C, TLC7528E, TLC7528I
DUAL 8-BIT MULTIPLYING
DIGITAL-TO-ANALOG CONVERTERS
SLAS062B – JANUARY 1987 – REVISED MARCH 2000
APPLICATION INFORMATION
Table 3. Attenuation vs DACA, DACB Code
CODE IN
CODE IN
DECIMAL
ATTN (dB)
DAC INPUT CODE
ATTN (dB)
DAC INPUT CODE
DECIMAL
255
242
228
215
203
192
181
171
162
152
144
136
128
121
114
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
1 1 1 1 1 1 1 1
1 1 1 1 0 0 1 0
1 1 1 0 0 1 0 0
1 1 0 1 0 1 1 1
1 1 0 0 1 0 1 1
1 1 0 0 0 0 0 0
1 0 1 1 0 1 0 1
1 0 1 0 1 0 1 1
1 0 1 0 0 0 1 0
1 0 0 1 1 0 0 0
1 0 0 1 1 1 1 1
1 0 0 0 1 0 0 0
1 0 0 0 0 0 0 0
0 1 1 1 1 0 0 1
0 1 1 1 0 0 1 0
0 1 1 0 1 1 0 0
8.0
8.5
0 1 1 0 0 1 1 0
0 1 1 0 0 0 0 0
0 1 0 1 1 0 1 1
0 1 0 1 0 1 1 0
0 1 0 1 0 0 0 1
0 1 0 0 1 1 0 0
0 1 0 0 1 0 0 0
0 1 0 0 0 1 0 0
0 1 0 0 0 0 0 0
0 0 1 1 1 1 0 1
0 0 1 1 1 0 0 1
0 0 1 1 0 1 1 0
0 0 1 1 0 0 1 1
0 0 1 1 0 0 0 0
0 0 1 0 1 1 1 0
0 0 1 0 1 0 1 1
102
96
91
86
81
76
72
68
64
61
57
54
51
48
46
43
9.0
9.5
10.0
10.5
11.0
11.5
12.0
12.5
13.0
13.5
14.0
14.5
15.0
15.5
108
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 is easy to achieve.
1
f
c
2
R1C1
The programmable range for the cutoff or center frequency is 0 to 15 kHz with a Q ranging from 0.3 to 4.5. This
defines the limits of the component values.
12
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TI [ TEXAS INSTRUMENTS ]
