Texas Instruments UC3524N, UC3524DWTR, UC3524J, UC3524DW, UC3524D Datasheet

Advanced Regulating Pulse Width Modulators

UC1524
UC2524
UC3524

FEATURES

Complete PWM Power Control

•

Circuitry

Uncommitted Outputs for

•

Single-ended or Push-pull
Applications

Low Standby Current…8mA Typical

•

Interchangeable with SG1524,

•

SG2524 and SG3524, Respectively

DESCRIPTION

The UC1524, UC2524 and UC3524 incorporate on a single monolithic chip
all the functions required for the construction of regulating power supplies, in
verters or switching regulators. They can also be used as the control element
for high-power-output applications. The UC1524 family was designed for
switching regulators of either polarity, transformer-coupled dc-to-dc convert
ers, transformerless voltage doublers and polarity converter applications em
ploying fixed-frequency, pulse-width modulation techniques. The dual
alternating outputs allow either single-ended or push-pull applications. Each
device includes an on-chip reference, error amplifier, programmable oscilla
tor, pulse-steering flip-flop, two uncommitted output transistors, a high-gain
comparator, and current-limiting and shut-down circuitry. The UC1524 is
characterized for operation over the full military temperature range of -55°C
to +125°C. The UC2524 and UC3524 are designed for operation from -25°C
to +85°C and 0° to +70°C, respectively.

-

-

-

-

BLOCK DIAGRAM

15

V

IN

6

R

T

7

C

T

(RAMP)

INV INPUT

NI INPUT

GROUND

(SUBSTRATE)

1

2

8

REFERENCE
REGULATOR

+5V

EA

10

V

REF

16

OSC

1k

OSC OUT

COMPARATOR

10k

3

+5V TO ALL

INTERNAL

Q

QR

CIRCUITRY

+5V

CL

11

13

14

5

4

C

A

E

A

C

B

E

B

–SENSE

+SENSE

+5V 12

9

SLUS180A - NOVEMBER 1999

SHUTDOWN

COMPENSATION

ABSOLUTE MAXIMUM RATINGS (Note 1)

Supply Voltage, VCC(Notes 2 and 3) . . . . . . . . . . . . . . . . . 40V

Collector Output Current. . . . . . . . . . . . . . . . . . . . . . . . . 100mA

Reference Output Current . . . . . . . . . . . . . . . . . . . . . . . . 50mA

Current Through C
Power Dissipation at T
Power Dissipation at T

Terminal . . . . . . . . . . . . . . . . . . . . . . –5mA

T

= +25°C (Note 4). . . . . . . . . . 1000mW

A

= +25°C (Note 4). . . . . . . . . . 2000mW

C

Operating Junction Temperature Range . . . . –55°C to +150°C

Storage Temperature Range . . . . . . . . . . . . . –65°C to +150°C

Note 1: Over operating free-air temperature range unless oth

erwise noted.

Note 2: All voltage values are with respect to the ground termi

nal, pin 8.

Note 3: The reference regulator may be bypassed for opera

tion from a fixed 5V supply by connecting the V

CC

-

and
reference output pins both to the supply voltage. In this
configuration the maximum supply voltage is 6V.

Note 4: Consult packaging section of databook for thermal lim

itations and considerations of package.

RECOMMENDED OPERATING CONDITIONS

Supply Voltage, VCC. . . . . . . . . . . . . . . . . . . . . . . . . . 8V to 40V

Reference Output Current . . . . . . . . . . . . . . . . . . . . . 0 to 20mA

Current through C
Timing Resistor, R
Timing Capacitor, C
Operating Ambient Temperature Range

UC1524 . . . . . . . . . . . . . . . . . . . . . . . . . . . . –55°C to +125°C

UC2524 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –25°C to +85°C

UC3524 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to +70°C

Terminal . . . . . . . . . . . . . –0.03mA to –2mA

T

. . . . . . . . . . . . . . . . . . . . . 1.8kΩ to 100kΩ

T

. . . . . . . . . . . . . . . . . . . 0.001µF to 0.1µF

T

CONNECTION DIAGRAM

INV INPUT

NON INV

INPUT

OSC OUT

-

-

-

CLSENSE(+)

CLSENSE (–-)

R

C

GND

T

T

UC1524
UC2524
UC3524

1

EA

2

3

4

CL

5

6

OSC

7

8

REF

REG

S/D

16

15

14

13

12

11

10

V

REF

V

IN

E

B

C

B

C

A

E

A

S/D

9

COMP

ELECTRICAL CHARACTERISTICS: Unless otherwise stated, these specifications apply for T

for the UC1524, –25°C to +85°C for the UC2524, and 0°C to +70°C for the UC3524, V
T

A=TJ

.

= 20V, and f = 20kHz,

IN

= –55°C to +125°C

A

UC1524/UC2524 UC3524 UNITS

PARAMETER TEST CONDITIONS

MIN MAX MIN MAX

Reference Section

Output Voltage 4.8 5.0 5.2 4.6 5.0 5.4 V
Line Regulation V
Load Regulation I
Ripple Rejection f = 120Hz, T
Short Circuit Current Limit V

IN = 8 to 40V 10 20 10 30 mV

L = 0 to 20mA 20 50 20 50 mV

J = 25°C 66 66 dB

REF = 0, TJ = 25°C 100 100 mA

Temperature Stability Over Operating Temperature Range 0.3 1 0.3 1 %
Long Term Stability T

J = 125°C, t = 1000 Hrs. 20 20 mV

Oscillator Section

Maximum Frequency C
Initial Accuracy R
Voltage Stability V

= .001mfd, RT= 2kΩ 300 300 kHz

T

and CTConstant 5 5 %

T

= 8 to 40V, TJ= 25°C 1 1 %

IN

Temperature Stability Over Operating Temperature Range 5 5 %
Output Amplitude Pin 3, T
Output Pulse Width C

T

= 25°C 3.5 3.5 V

J

= .01mfd, TJ= 25°C 0.5 0.5

Error Amplifier Section

Input Offset Voltage V
Input Bias Current V

= 2.5V 0.5 5 2 10 mV

CM

= 2.5V 2 10 2 10

CM

Open Loop Voltage Gain 72 80 60 80 dB
Common Mode Voltage T

= 25°C 1.8 3.4 1.8 3.4 V

J

2

µs

µA