CA1524 Datasheet, PDF (13/16 Pages) Intersil Corporation – Regulating Pulse Width Modulator

CA1524, CA2524, CA3524
+5
V_REFERENCE
2K
TO PIN 9
1.1K
1.1K
DUTY CYCLE
R2
ADJUSTMENT
10K
2K
FREQUENCY
ADJUSTMENT
20K
R1
50K
0.1µF
SILVER
MICA
1
16
2
15
3
14
4 _CA3524 13
5
12
6
11
7
10
8
9
V⁺ = 9V
1.5K
1_/2S2
TO PIN 12 TO PIN 13
OUTPUT 1 OUTPUT 2
OUTPUT 1A
1_/2S1
1_/2S2
1.5K
1_/2S1
OUTPUT 2A
TO PIN 1
SWITCH
S1
S2
OUTPUT
PULSES
0V - 5V
-
DUTY
CYCLE
0% - 45%
0% - 90%
FIGURE 22. LOW-FREQUENCY PULSE GENERATOR
The Variable Switcher
The circuit diagram of the CA1524, used as a variable output
voltage power supply is shown in Figure 23. By connecting
the two output transistors in parallel, the duty cycle is
doubled, i.e., 0% - 90%. As the reference voltage level is
varied, the feedback voltage will track that level and cause
the output voltage to change according to the change in
reference voltage.
D1
AC
IN
D2
D1-D4 - A15A
D3
36
D4
5100µF
100V
2N6385
(PNP DARLINGTON)
V_DC
Q1
R2
1.5
R1
10W
1K
1W
0.01µF
L1
20mH
D5
RURD410
C3
10000µF
100V
L2
50mH
BIFILAR
WINDING
C4
0.1µF
C7
0.1µF
R3
10K
R6
2K
R4
5K
R7
10K
R5
2K
R8
2K
16 15 14 13 12 11 10 9
CA1524
12
3
4
5
6
7
8
C8
0.1µF
R9
C9
15K
3300
1%
pF
1%
R10
16K
C11
0.01µF
C10
1100pF
SILVER
MICA
7V - 30V
0A - 3A
V_OUT
C5
25µF
NON-POLAR
RETURN
C6
25µF
NON-POLAR
VOLTAGE
CONTROL
f_OSC = 20KHz
FIGURE 23. THE CA1524 USED AS A 0-5A, 7-30 V LABORATORY SUPPLY
13