Datasheet

6
FIGURE 5. AVERAGING AC TO DC CONVERTER FOR A/D
CONVERTERS SUCH AS ICL7106, ICL7107,
ICL7109, ICL7116, ICL7117
FIGURE 6. BURN-IN AND LIFE TEST CIRCUIT
FIGURE 7. FIFTH ORDER CHEBYCHEV MULTIPLE FEEDBACK LOW PASS FILTER
10µF
1/2
+
-
20kΩ
V
IN
20kΩ
V
OH
V
OL
1MΩ
2.2MΩ
COMMON
10kΩ
0.5µF
1.8k = 5%
SCALE
ADJUST
TO
SUCCEEDING
INPUT
STAGE
+
-
ICL7621
1/2
ICL7621
+
-
V-
OUT
V+
V+
-8V
+8V
T
A
= 125
o
C
+
-
+
-
INPUT
30kΩ 160kΩ
0.2µF
0.2µF
0.2µF
0.2µF 0.1µF0.1µF
51kΩ100kΩ680kΩ
360kΩ
360kΩ
1MΩ
1MΩ
OUTPUT
1/2
ICL7621
1/2
ICL7621
NOTE 4
NOTE 4
NOTES:
4. Small capacitors (25 - 50pF) may be needed for stability in some cases.
5. The low bias currents permit high resistance and low capacitance values to be used to achieve low frequency cutoff. f
C
= 10Hz, AV
CL
=4,
Passband ripple = 0.1dB.
Typical Performance Curves
FIGURE 8. SUPPLY CURRENT PER AMPLIFIER vs SUPPLY
VOLTAGE
FIGURE 9. SUPPLY CURRENT PER AMPLIFIER vs FREE-AIR
TEMPERATURE
10K
1K
100
10
1
SUPPLY CURRENT (µA)
0246810121416
SUPPLY VOLTAGE (V)
T
A
= 25
o
C
NO LOAD
NO SIGNAL
I
Q
= 1mA
I
Q
= 100µA
I
Q
= 1mAI
Q
= 10µA
10
4
10
3
10
2
10
1
SUPPLY CURRENT (µA)
-50 -25 0 25 50 75 100 125
FREE-AIR TEMPERATURE (
o
C)
V+ - V- = 10V
NO LOAD
NO SIGNAL
I
Q
= 1mA
I
Q
= 100µA
I
Q
= 10µA
ICL7621, ICL7641, ICL7642