4/90 Rev 1.1 2/94

Copyright

© 1994

11861 Western Avenue

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(714) 898-8121

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SG1526/SG2526/SG3526

REGULATING PULSE WIDTH MODULATOR

FEATURES

••••• 8 to 35 volt operation

••••• 5V reference trimmed to ±1%

••••• 1Hz to 350KHz oscillator range

••••• Dual 100mA source/sink outputs

••••• Digital current limiting

••••• Double pulse suppression

••••• Programmable deadtime

••••• Undervoltage lockout

••••• Single pulse metering

••••• Programmable soft-start

••••• Wide current limit common mode range

••••• TTL/CMOS compatible logic ports

••••• Symmetry correction capability

••••• Guaranteed 6 unit synchronization

HIGH RELIABILITY FEATURES - SG1526

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♦ Available to MIL-STD-883B and DESC SMD

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♦ Radiation data available

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♦ LMI level "S"processing available

DESCRIPTION

The SG1526 is a high performance monolithic pulse width modulator

circuit designed for fixed-frequency switching regulators and other

power control applications. Included in an 18-pin dual-in-line package

are a temperature compensated voltage reference, sawtooth oscillator,

error amplifier, pulse width modulator, pulse metering and steering logic,

and two low impedance power drivers. Also included are protective

features such as soft-start and undervoltage lockout, digital current

limiting, double pulse inhibit, a data latch for single pulse metering,

adjustable deadtime, and provision for symmetry correction inputs. For

ease of interface, all digital control ports are TTL and B-series CMOS

compatible. Active LOW logic design allows wired-OR connections for

maximum flexibility. This versatile device can be used to implement

single-ended or push-pull switching regulators of either polarity, both

transformerless and transformer coupled. The SG1526 is characterized

for operation over the full military ambient junction temperature range of

-55°C to +150°C. The SG2526 is characterized for operation from -25°C

to +150°C, and the SG3526 is characterized for operation from 0°C to

+125°C.

+V

IN

To Internal

Circuitry

V

REF

METERING

F/F

TOGGLE

F/F

MEMORY

F/F

SYNC

R

D

R

T

C

T

GROUND

Oscillator

Reference

Regulator

Undervoltage

Lockout

Soft

Start

RESET

C

SOFTSTART

COMPENSATION

+ ERROR

— ERROR

+ C.S.

— C.S.

SHUTDOWN

S

D

S

T

Q

Q

Q

R

OUTPUT B

+V

C

OUTPUT A

BLOCK DIAGRAM

+V

IN

Amp

Q

Q