SG1526/SG2526/SG3526
REGULATING PULSE WIDTH MODULATOR
FEATURES
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.
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8V to 35V Operation
5V Reference Trimmed to ±1%
1Hz to 350kHz Oscillator Range
Dual 100mA Source/Sink Outputs
Digital Current Limiting
Double Pulse Suppression
. Programmable Deadtime
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. Programmable Soft-start
. Wide Current Limit Common Mode
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Undervoltage Lockout
Single Pulse Metering
Range TTL/CMOS Compatible Logic
Ports Symmetry Correction Capability
Guaranteed 6 Unit Synchronization
HIGH RELIABILITY FEATURES
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Available to MIL-STD-883, ¶ 1.2.1
. Available to DSCC - Standard Microcircuit
Drawing (SMD)
Radiation data available
MSC-AMS level "S" processing available
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BLOCK DIAGRAM
VREF
+VC
Reference
Regulator
Undervoltage
Lockout
+VIN
GROUND
SYNC
To Internal
Circuitry
RD
RT
Oscillator
OUTPUT A
CT
RESET
CSOFTSTART
Soft
Start
S
Q
T
COMPENSATION
+VIN
Amp
R
Q
Q
S
MEMORY
F/F
TOGGLE
F/F
Q
Q
+ ERROR
— ERROR
D
OUTPUT B
METERING
F/F
+ C.S.
— C.S.
SHUTDOWN
December 2014 Rev1.2
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