4/90 Rev 1.1 2/94
Copyright
1994
L
IN
F
IN
ITY
Microelectronics Inc.
11861 Western Avenue
∞
∞
Garden Grove, CA 92841
(714) 898-8121
∞
FAX: (714) 893-2570
1
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
Available to MIL-STD-883B and DESC SMD
Radiation data available
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