Intersil Corporation CA3524, CA2524, CA1524 Datasheet

7-16

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
407-727-9207

| Copyright © Intersil Corporation 1999

CA1524, CA2524

CA3524

Regulating Pulse Width Modulator

Description

The CA1524, CA2524, and CA3524 are silicon monolithic
integrated circuits designed to provide all the control circuitry
for use in a broad range of switching regulator circuits.

The CA1524, CA2524, and CA3524 have all the features of
the industry types SG1524, SG2524, and SG3524,
respectively. A block diagram of the CA1524 series is shown
in Figure 1. The circuit includes a zener voltage reference,
transconductance error amplifier, precision R-C oscillator,
pulse-width modulator, pulse-steering flip-flop, dual alternat­ing output switches, and current-limiting and shutdown
circuitry. This device can be used for switching regulators of
either polarity, transformer-coupled dc-dc converter,
transformerless voltage doublers, dc-ac power inverters,
highly efficient variable power supplies, and polarity
converter, as well as other power-control applications.

Ordering Information

PART

NUMBER

TEMPERATURE

RANGE PACKAGE

CA1524E -55oC to +125oC 16 Lead Plastic DIP
CA1524F -55oC to +125oC 16 Lead CerDIP
CA2524E 0oC to +70oC 16 Lead Plastic DIP
CA2524F 0oC to +70oC 16 Lead CerDIP
CA3524E 0oC to +70oC 16 Lead Plastic DIP
CA3524F 0oC to +70oC 16 Lead CerDIP

Features

• Complete PWM Power Control Circuitry

• Separate Outputs for Single-Ended or Push-Pull
Operation

• Line and Load Regulation. . . . . . . . . . . . . . . 0.2% (Typ)

• Internal Reference Supply with 1% (Max) Oscillator
and Reference Voltage Variation Over Full
Temperature Range

• Standby Current of Less Than 10mA

• Frequency of Operation Beyond 100kHz

• Variable-Output Dead Time of 0.5µs to 5µs

• Low V

CE(sat)

Over the Temperature Range

Applications

• Positive and Negative Regulated Supplies

• Dual-Output Regulators

• Flyback Converters

• DC-DC Transformer-Coupled Regulating Converters

• Single-Ended DC-DC Converters

• Variable Power Supplies

File Number

1239.3

Pinout

CA1524, CA2524, CA3524

(PDIP, CERDIP)

TOP VIEW

14

15

16

9

13

12

11

10

1

2

3

4

5

7

6

8

C

T

R

T

V

REF

EMITTER B
COLLECTOR B

COLLECTOR A
EMITTER A

SHUTDOWN

INV. INPUT

OSC OUT

GND

(-) C.L.

SENSE

(+) C.L.
SENSE

V+

COMPENSATION
AND COMPARATOR

NON-

INV. INPUT

April 1994

7-17

CA1524, CA2524, CA3524

Functional Block Diagram

Test Circuit

REFERENCE
REGULATOR

5V

FLIP

OSCILLATOR

COMPARATOR

INV. INPUT

NON-INV.
INPUT

ERROR

AMP

SHUTDOWN

GND

16

15

3

6

7

1

2

10

8

FLOP

+5V

+5V TO ALL
INTERNAL CIRCUITS

+5V

-

+

+5V

+5V

C.L.

+5V

+

-

10kΩ

1kΩ

9

5

4

COMPENSATION AND COMPARATOR

- SENSE

+ SENSE

12

11

S

A

E

A

C

A

13

14

S

B

E

B

C

B

C

T

R

T

OSC OUT

V

REF

V+

12

13

11

14

5410912768

16

15

3

ls

CA1524

V+

8 - 40V

0.1µF

R

T

C

T

2kΩ

10kΩ

1kΩ

10

kΩ

2kΩ

2kΩ

2kΩ

1W

2kΩ
1W

OUT A

OUT B

7-18

Specifications CA1524, CA2524, CA3524

Absolute Maximum Ratings Thermal Information

Input Voltage (Between VIN and GND Terminals) . . . . . . . . . . . 40V

Operating Voltage Range (VIN to GND) . . . . . . . . . . . . . . . .8 to 40V

Output Current Each Output:

(Terminal 11, 12 or 13, 14) . . . . . . . . . . . . . . . . . . . . . . . . . 100mA

Output Current (Reference Regulator). . . . . . . . . . . . . . . . . . .50mA

Oscillator Charging Current . . . . . . . . . . . . . . . . . . . . . . . . . . . .5mA

Thermal Resistance θ

JA

Plastic DIP Package . . . . . . . . . . . . . . . . . . . . . . . . 100oC/W

Device Dissipation

Up to TA = +25oC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.25W

Above TA = +25oC. . . . . . . . . . . . . . .Derate Linearly at 10mW/oC

Operating Temperature Range . . . . . . . . . . . . . . . .-55oC to +125oC

Storage Temperature Range. . . . . . . . . . . . . . . . . .-65oC to +150oC

Lead Temperature (During Soldering)

At distance 1/16 ± in. (1.59mm ±0.79mm)

from case for 10s Max. . . . . . . . . . . . . . . . . . . . . . . . . . . . +265oC

CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation
of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied.

Electrical Specifications T

A

= -550C to +125oC for CA1524, 0oC to +70oC for the CA2524 and CA3524; V+ = 20V and

f = 20kHz, Unless Otherwise Stated.

PARAMETER TEST CONDITIONS

CA1524, CA2524 CA3524

UNITSMIN TYP MAX MIN TYP MAX

REFERENCE SECTION
Output Voltage 4.8 5 5.2 4.6 5 5.4 V
Line Regulation V+ = 8 to 40V - 10 20 - 10 30 mV
Load Regulation IL = 0 to 20mA - 20 50 - 20 50 mV
Ripple Rejection f = 120Hz, TA = 25oC - 66 - - 66 - db
Short Circuit Current Limit V

REF

= 0, TA = 25oC - 100 - - 100 - mA

Temperature Stability Over Operating Temperature

Range

- 0.3 1 - 0.3 1 %

Long Term Stability TA = 25oC - 20 - - 20 - mV/khr
OSCILLATOR SECTION
Maximum Frequency CT = 0.001µF, RT = 2KΩ - 300 - - 300 - kHz
Initial Accuracy RT and CT Constant - 5 - - 5 - %
Voltage Stability V+ = 8 to 40V, TA = 25oC--1--1%
Temperature Stability Over Operating Temperature

Range

--2--2 %

Output Amplitude Terminal 3, TA = 25oC - 3.5 - - 3.5 - V
Output Pulse Width (Pin 3) CT = 0.01µF, TA = 25oC - 0.5 - - 0.5 - µs
Ramp Voltage Low (Note 1) Pin 7 - 0.6 - - 0.6 - V
Ramp Voltage High (Note 1) Pin 7 - 3.5 - - 3.5 - V
Capacitor Charging Current Range Pin 7 (5-2 VBE)/R

T

0.03 - 2 0.03 - 2 mA
Timing Resistance Range Pin 6 1.8 - 120 1.8 - 120 kΩ
Charging Capacitor Range Pin 7 0.001 - 0.1 0.001 - 0.1 µF
Dead Time Expansion Capacitor on

Pin 3 (when a small osc. cap is used)

Pin 3 100 - 1000 100 - 1000 pF

ERROR AMPLIFIER SECTION
Input Offset Voltage VCM = 2.5V - 0.5 5 - 2 10 mV
Input Bias Current VCM = 2.5V - 1 10 - 1 10 µA
Open Loop Voltage Gain 72 80 - 60 80 - dB
Common Mode Voltage TA = 25oC 1.8 - 3.4 1.8 - 3.4 V
Common Mode Rejection Ratio TA = 25oC - 70 - - 70 - dB
Small Signal Bandwidth AV = 0dB, TA = 25oC - 3 - - 3 - MHz

7-19

Specifications CA1524, CA2524, CA3524

Output Voltage TA = 25oC 0.5 - 3.8 0.5 - 3.8 V
Amplifier Pole - 250 - - 250 - Hz
Pin 9 Shutdown Current External Sink - 200 - - 200 - µA
COMPARATOR SECTION
Duty Cycle % Each Output On 0 - 45 0 - 45 %
Input Threshold Zero Duty Cycle - 1 - - 1 - V
Input Threshold Max. Duty Cycle - 3.5 - - 3.5 - V
Input Bias Current - 1 - - 1 - µA
CURRENT LIMITING SECTION
Sense Voltage for 25% Output Duty

Cycle

Terminal 9 = 2V with Error
Amplifier Set for Max Out,
TA = 25oC

190 200 210 180 200 220 mV

Sense Voltage T.C. - 0.2 - - 0.2 - mV/oC
Common Mode Voltage -1 - +1 -1 - +1 V
Rolloff Pole of R51 C3 + Q64 - 300 - - 300 - Hz
OUTPUT SECTION (EACH OUTUT)
Collector-Emitter Voltage 40 - - 40 - - V
Collector Leakage Current VCE = 40V - 0.1 50 - 0.1 50 µA
Saturation Voltage V+ = 40V, IC = 50mA - 0.8 2 - 0.8 2 V
Emitter Output Voltage V+ = 20V 17 18 - 17 18 - V
Rise Time RC = 2KΩ, TA = 25oC - 0.2 - - 0.2 - µs
Fall Time RC = 2KΩ, TA = 25oC - 0.1 - - 0.1 - µs
Total Standby Current: (Note 2) I

S

V+ = 40V - 4 10 - 4 10 mA

NOTES:

1. Ramp voltage at Pin 7 where t = OSC period in microseconds

t ≅ RTCT with CT in microfarads and RT in ohms.
Output frequency at each output transistor is half OSC frequency when each output is used separately and is equal to the OSC frequency
when each output is connected in parallel.

2. Excluding oscillator charging current, error and current limit dividers, and with outputs open.

Electrical Specifications T

A

= -550C to +125oC for CA1524, 0oC to +70oC for the CA2524 and CA3524; V+ = 20V and

f = 20kHz, Unless Otherwise Stated. (Continued)

PARAMETER TEST CONDITIONS

CA1524, CA2524 CA3524

UNITSMIN TYP MAX MIN TYP MAX

High
Low

t

7-20

CA1524, CA2524, CA3524

Schematic Diagram

21

3

7

6

8

Q1

R1

500

R5
1K

R7
1K

Q2

Q7

Q13

Q6

Q3 Q4

R2

2.7K

RC

10K

R3

6.3K

Q10

Q11

D2

D1

Q9

C1

20pF

R4

500

R6

500

Q5 Q12

RB

4.8K

RA

5.3K

QA

OSC SECTION

Q42 Q43

Q44

Q47 Q48

Q49 Q50

Q45

Q46

R39
1K

R41
24K

R40

560

R42

19.8K

Q51

Q52

R45
25K

R44

1.8K

R43

7.4K

Q53

Q54

Q55

R46

3.3K

OSC.

OUT

Q59 Q60

Q61

Q56 Q57

INV.

IN

ERROR

AMP

NON-INV.
INPUT

Q58 Q62

R471KR48

2K

J

K
L

F
G
H

I

C

D
E

Q24

Q22

Q20

R15
25K

C2

20pF

N

+

P

10K 1.9K

RD

Q19

R14
450

Q14 Q15

R8

8.4K

R9
500

R10
1K

Q17

Q18

R11
500

R12
10K

Q16

R13

6Ω

15

V

IN

C4

PULSE
STEERING
FLIP-FLOP

B

A

R16

16.2K

R19

18.7
K

R17

18.7
K

R18

18.7
K

R18

18.7
K

Q21 Q23

16

V

REF

+5V

GND

R

T

C

T