CA3524E Intersil, CA3524E Datasheet - Page 12

• Manufacturer Part Number: CA3524E
• Description: REGUL. PULSE WIDTH MODULATOR
• Manufacturer: Intersil

Specifications of CA3524E

• Rohs Status: RoHS non-compliant
• Other names: CA3524

Flyback Converter
Figure 20 shows a flyback converter circuit for generating a
dual 15V output at 20mA from a 5V regulated line.
Reference voltage is provided by the input and the internal
reference generator is unused. Current limiting in this circuit
is accomplished by sensing current in the primary line and
resetting the soft-start circuit.
Push-Pull Converter
The output stages of the CA1524 provide the drive for
transistors Q1 and Q2 in the push-pull application of Figure
21. Since the internal flip-flop divides the oscillator frequency
by two, the oscillator must be set at twice the output
frequency. Current limiting for this circuit is done in the
primary of transformer T1 so that the pulse width will be
reduced if transformer saturation should occur.
+28V
+5V
100 F
V+
V+
+
5K
5K
0.1 F
5K
5K
25K
0.01 F
5K
0.02 F
2K
5K
5K
2K
FIGURE 21. PUSH-PULL TRANSFORMER-COUPLED CONVERTER
1 16
1 16
1 10
1 10
1 1
1 2
1 6
1 7
1 3
1
1
1 2
1 6
1 7
1 3
FIGURE 20. FLYBACK CONVERTER CIRCUIT
CA1524, CA2524, CA3524
CA3524
1 15
1 15
1 8
1 8
0.001 F
20K
1 12
1 11
1 13
1 14
1 12
1 11
1 13
1 14
300
1 4
1 5
1 9
12
1 4
1K
1 5
1 9
1W
Low-Frequency Pulse Generator
Figure 22 shows the CA1524 being used as a low-frequency
pulse generator. Since all components (error amplifier,
oscillator, oscillator reference regulator, output transistor
drivers) are on the lC, a regulated 5-V (or 2.5-V) pulse of 0%
- 45% (or 0% - 90%) on time is possible over a frequency
range of 150 to 500Hz. Switch S1 is used to go from a 5-V
output pulse (S1 closed) to a 2.5-V output pulse (S1 open)
with a duty cycle range of 0% to 45%. The output frequency
will be roughly half of the oscillator frequency when the
output transistors are not connected in parallel (75Hz to
250Hz, respectively). Switch S2 will allow both output stages
to be paralleled for an effective duty cycle of 0%-90% with
the output frequency range from 150 to 500Hz. The
frequency is adjusted by R1; R2 controls duty cycle.
1K
1W
IN914
0.001 F
1K
1K
1M
2N6292
2N6292
+
4.7 F
0.1 F
200
0.1 F
2N2102
510
620
+
100 F
20T
20T
20T
RURD620
RURD620
5T
RURD620
5T
2N6290
1
CORE: FEROX CUBE
2213P - A250 - 387
OR EQUIVALENT
RURD620
50T
50T
1mH
1500 F
50 F
50 F
+
+15V
-15V
5V
5A