ICL8038AMJD/883B View Datasheet(PDF) - Harris Semiconductor
Part Name
Description
MFG CO.
'ICL8038AMJD/883B' PDF : 10 Pages View PDF
ICL8038
Typical Applications
The sine wave output has a relatively high output impedance
(1kΩ Typ). The circuit of Figure 6 provides buffering, gain
and amplitude adjustment. A simple op amp follower could
also be used.
RA
74
RB
5
8
ICL8038
6 2 AMPLITUDE
+
100K 741
-
V+
10K
FREQ.
20K
0.1µF
1N457
DUTY CYCLE
1K
4.7K
4.7K
+10V
15K
5
4
69
8
ICL8038
3
10
11
4.7K
C
V-
FIGURE 6. SINE WAVE OUTPUT BUFFER AMPLIFIERS
10
11
12 2
20K ≈15M
0.0047µF
DISTORTION
100K
-10V
IGURE 8. VARIABLE AUDIO OSCILLATOR, 20Hz TO 20kHzY
With a dual supply voltage the external capacitor on Pin 10 can
be shorted to ground to halt the ICL8038 oscillation. Figure 7
shows a FET switch, diode ANDed with an input strobe signal
to allow the output to always start on the same slope.
RA
RB
V+
15K
74
5
9
8
ICL8038
1N914
11
10 2
C
2N4392
-15V
1N914
STROBE
100K
OFF
ON
+15V (+10V)
-15V (-10V)
FIGURE 7. STROBE TONE BURST GENERATOR
To obtain a 1000:1 Sweep Range on the ICL8038 the volt-
age across external resistors RA and RB must decrease to
nearly zero. This requires that the highest voltage on control
Pin 8 exceed the voltage at the top of RA and RB by a few
hundred mV. The Circuit of Figure 8 achieves this by using a
diode to lower the effective supply voltage on the ICL8038.
The large resistor on pin 5 helps reduce duty cycle variations
with sweep.
The linearity of input sweep voltage versus output frequency
can be significantly improved by using an op amp as shown
in Figure 9.
8-159
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