BLOCK DIAGRAM

UC1526A

UC2526A

UC3526A

Regulating Pulse Width Modulator

FEATURES

• Reduced Supply Current

• Oscillator Frequency to 600kHz

• Precision Band-Gap Reference

• 7 to 35V Operation

• Dual 200mA Source/Sink Outputs

• Minimum Output Cross-Conduction

• Double-Pulse Suppression Logic

• Under-Voltage Lockout

• Programmable Soft-Start

• Thermal Shutdown

• TTL/CMOS Compatible Logic Ports

• 5 Volt Operation (V

IN = VC = VREF = 5.0V)

DESCRIPTION

The UC1526A Series are improved-performance pulse-width modu-

lator circuits intended for direct replacement of equivalent non- “A”

versions in all applications. Higher frequency operation has been

enhanced by several significant improvements including: a more ac-

curate oscillator with less minimum dead time, reduced circuit de-

lays (particularly in current limiting), and an improved output stage

with negligible cross-conduction current. Additional improvements

include the incorporation of a precision, band-gap reference gener-

ator, reduced overall supply current, and the addition of thermal

shutdown protection.

Along with these improvements, the UC1526A Series retains the

protective features of under-voltage lockout, soft-start, digital cur-

rent limiting, double pulse suppression logic, and adjustable

deadtime. For ease of interfacing, all digital control ports are TTL

compatible with active low logic.

Five volt (5V) operation is possible for “logic level” applications by

connecting V

IN, VC and VREF to a precision 5V input supply. Consult

factory for additional information.

6/93

RECOMMENDED OPERATING CONDITIONS

(Note 3)

Input Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +7V to +35V

Collector Supply Voltage . . . . . . . . . . . . . . . . . . +4.5V to +35V

Sink/Source Load Current (each output) . . . . . . . . 0 to 100mA

Reference Load Current . . . . . . . . . . . . . . . . . . . . . . 0 to 20mA

Oscillator Frequency Range . . . . . . . . . . . . . . . . 1Hz to 600kHz

Oscillator Timing Resistor. . . . . . . . . . . . . . . . . . . 2kΩ to 150kΩ

Oscillator Timing Capacitor. . . . . . . . . . . . . . . . . 400pF to 20µF

Available Deadtime Range at 40kHz . . . . . . . . . . . . 1% to 50%

Operating Ambient Temperature Range

UC1526A. . . . . . . . . . . . . . . . . . . . . . . . . . . . -55°C to +125°C

UC2526A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . -25°C to +85°C

UC3526A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to +70°C

ABSOLUTE MAXIMUM RATINGS (Note 1, 2)

Input Voltage (+VIN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +40V

Collector Supply Voltage (+V

C) . . . . . . . . . . . . . . . . . . . . . +40V

Logic Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +5.5V

Analog Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +V

Source/Sink Load Current (each output) . . . . . . . . . . . . 200mA

Reference Load Current. . . . . . . . . . . . . . . . . . . . . . . . . . 50mA

Logic Sink Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15mA

Power Dissipation at T

A = +25°C (Note 2) . . . . . . . . . 1000mW

Power Dissipation at T

C = +25°C (Note 2). . . . . . . . . . 3000mW

Operating Junction Temperature . . . . . . . . . . . . . . . . . . +150°C

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

Lead Temperature (soldering, 10 seconds) . . . . . . . . . . +300°C

CONNECTION DIAGRAMS

PACKAGE PIN FUNCTION

FUNCTION PIN

N/C 1

+ERROR 2

-ERROR 3

COMP. 4

SS 5

RESET 6

- CURRENT SENSE 7

+ CURRENT SENSE 8

SHUTDOWN 9

TIMING 10

T 11

D 12

SYNC 13

OUTPUT A 14

C 15

N/C 16

GROUND 17

OUTPUT B 18

IN 19

REF 20

PLCC-20, LCC-20

(TOP VIEW)

Q and L Packages

DIL-18, SOIC-18 (TOP VIEW)

J or N Package, DW Package

Note 1: Values beyond which damage may occur.

Note 2: Consult packaging Section of Databook for thermal

limitations and considerations of package.

Note 3: Range over which the device is functional and

parameter limits are guaranteed.

UC1526A

UC2526A

UC3526A

PARAMETER TEST CONDITIONS

UC1526A / UC2526A UC3526A

UNITS

MIN TYP MAX MIN TYP MAX

Reference Section (Note 4)

Output Voltage T

J = +25°C 4.95 5.00 5.05 4.90 5.00 5.10 V

Line Regulation +V

IN = 7 to 35V 2 10 2 15 mV

Load Regulation I

L = 0 to 20mA 5 20 5 20 mV

Temperature Stability Over Operating T

J (Note 5) 15 50 15 50 mV

Total Output Voltage

Range

Over Recommended Operating

Conditions

4.90 5.00 5.10 4.85 5.00 5.15 V

Short Circuit Current V

REF = 0V 25 50 100 25 50 100 mA

Under-Voltage Lockout

RESET Output Voltage VREF = 3.8V 0.2 0.4 0.2 0.4 V

VREF = 4.7V 2.4 4.7 2.4 4.8 V

Oscillator Section (Note 6)

Initial Accuracy T

J = +25°C ±3 ±8 ±3 ±8%

Voltage Stability +V

IN = 7 to 35V 0.5 1 0.5 1 %

Temperature Stability Over Operating T

J (Note 5) 26 13%

Minimum Frequency R

T = 150kΩ, CT = 20µF (Note 5) 1 1 Hz

Maximum Frequency R

T = 2kΩ, CT = 470pF 550 650 kHz

Sawtooth Peak Voltage +V

IN = 35V 3.0 3.5 3.0 3.5 V

Sawtooth Valley Voltage +V

IN =7V 0.5 1.0 0.5 1.0 V

SYNC Pulse Width TJ = 25°C, RL = 2.7kΩ to V

REF

1.1 1.1 µs

Error Amplifier Section (Note 7)

Input Offset Voltage R

S ≤ 2kΩ 25 210mV

Input Bias Current -350 -1000 -350 -2000 nA

Input Offset Current 35 100 35 200 nA

DC Open Loop Gain R

L ≥ 10MΩ 64 72 60 72 dB

HIGH Output Voltage V

PIN 1 - VPIN 2 ≥ 150mV, ISOURCE = 100µA 3.6 4.2 3.6 4.2 V

LOW Output Voltage V

2 - VPIN 1 ≥ 150mV, ISINK = 100µA 0.2 0.4 0.2 0.4 V

Common Mode Rejection R

S ≤ 2kΩ 70 94 70 94 dB

Supply Voltage Rejection +V

IN = 12 to 18V 66 80 66 80 dB

PWM Comparator (Note 6)

Minimum Duty Cycle V

COMPENSATION = +0.4V 0 0 %

Maximum Duty Cycle V

COMPENSATION = +3.6V 45 49 45 49 %

Digital Ports (

SYNC, SHUTDOWN, and RESET)

HIGH Output Voltage I

SOURCE = 40µA 2.4 4.0 2.4 4.0 V

LOW Output Voltage I

SINK = 3.6mA 0.2 0.4 0.2 0.4 V

HIGH Input Current V

IH = +2.4V -125 -200 -125 -200 µA

LOW Input Current V

IL = +0.4V -225 -360 -225 -360 µA

Shutdown Delay From Pin 8, T

J = 25°C 160 160 ns

Current Limit Comparator (Note 8)

Sense Voltage R

S ≤ 50Ω 90 100 110 80 100 120 mV

Input Bias Current -3 -10 -3 -10 µA

Shutdown Delay From pin 7, 100mV Overdrive, T

J = 25°C 260 260 ns

IN = 15V, and over operating ambient temperature, unless otherwise specified TA = TJ.

ELECTRICAL CHARACTERISTICS:

Note 4: I

L =

0mA.

Note 5: Guaranteed by design, not 100% tested in production.

Note 6: F

OSC

= 40kHz, (R

= 4.12k

Ω

1%, C

= 0.01

1%,

= 0

Ω

Note 7: V

= 0 to +5.2V

Note 8: V

= 0 to +12V.

Note 9: V

= +15V.

Note 10:V

= +35V, R

= 4.12k

Ω

UC1526A

UC2526A

UC3526A

Part #	UC1526AJ/883B
Description	Voltage Mode PWM Controller 100mA 18-Pin CDIP Tube - Rail/
Category	IC
Availability	In Stock
Qty	6

Qty	Price
1 - 1	$27.55228
2 - 2	$21.91659
3 - 3	$20.66421
4 - 5	$19.20310
6 +	$17.11581

Manufacturer	Available	Qty
Texas Instruments Date Code: 0520	Freelance Stock: 1 Ships Immediately
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UC1526AJ/883B

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