MC1776C Datasheet, PDF (9/12 Pages) ON Semiconductor – PROGRAMMABLE OPERATIONAL AMPLIFIER

Figure 13. Wien Bridge Oscillator
22 k
200 k +15 V
10 k
2
7
–
6
MC1776C
3
+
8
VO
4
Rset
–15 V
C
RR
C
MC1776C
Figure 15. Multiple Feedback Bandpass Filter
(1.0 kHz)
C
R5
+15 V
R1
Input
2 _–7
C
6
MC1776C
3
Output
R2
+8
4
2.0 M
for a 1.0 kHz filter
with Q = 10
and A (fo) = 1
R1 = 160 k
R2 = 820
R5 = 300 k
C = 0.01 µF
–15 V
1
fo = _{2π RC}
R= 16 kΩ
C = 0.01 µF
(for fo = 1.0 kHz)
Figure 14. Multiple Feedback Bandpass Filter
Vin ^R1
CC
R5
2
VCC
7
–
6
MC1776C
R2
3
+8
VO
4
Rset
For a given:
fo = center frequency
A (fo) = Gain at center frequency
Q = quality factor
VEE
Choose a value for C, then
R5 =
Q
πfoC
R1 =
R5
2A (fo)
R2 =
R1,R5
4Q2 R1–R5
To obtain less than 10% error from the operational amplifier:
QO fo
≤ 0.1
GBW
where fo and GBW are expressed in Hz. GBW is available from
Figure 6 as a function of Set Current, Iset.
Figure 16. Gated Amplifier
10 k
2
3
Input
10 k
10 k
Gate
5.6 k
1M
+15 V
7
–
6
MC1776C
+4
–15 V
8
2.7 M
270 k
Q
Output
VCC
15 V
Figure 17. High Input Impedance Amplifier
50 M
10 k
500 k
Input
500 k
50 M
+15 V
2
–
7
MC1776C
3
+
4
8
–15 V
30 M
90 k
6
Output
MOTOROLA ANALOG IC DEVICE DATA
9