
D E S C R I P T I O N
The SG1825C is a high-performance
pulse width modulator optimized for
high frequency current-mode power
supplies. Included in the controller
are a precision voltage reference,
micropower start-up circuitry, soft-
start, high-frequency oscillator,
wideband error amplifier, fast current-
limit comparator, full double-pulse
suppression logic, and dual totem-
pole output drivers. Innovative
circuit design and an advanced linear
Schottky process result in very short
propagation delays through the
K E Y F E AT U R E S
I
IMPROVED REFERENCE INITIAL
TOLERANCE
(±1% max.)
I
IMPROVED OSCILLATOR INITIAL
ACCURACY
(±3% typ.)
I
IMPROVED STARTUP CURRENT
(500μA typ.)
I
PROP DELAY TO OUTPUTS
(50ns typ.)
p
10V TO 30V OPERATION
p
5.1V REFERENCE TRIMMED TO ±1%
p
2MHZ OSCILLATOR CAPABILITY
p
1.5A PEAK TOTEM-POLE DRIVERS
p
U.V. LOCKOUT WITH HYSTERESIS
p
NO OUTPUT DRIVER "FLOAT"
p
PROGRAMMABLE SOFTSTART
p
DOUBLE-PULSE SUPPRESSION LOGIC
p
WIDEBAND LOW-IMPEDANCE ERROR
AMPLIFIER
p
CURRENT-MODE OR VOLTAGE-MODE
CONTROL
p
WIDE CHOICE OF HIGH-FREQUENCY
PACKAGES
HIGH RELIABILITY FEATURES
I
AVAILABLE TO MIL-STD-883B
I
LINFINITY LEVEL "S" PROCESSING AVAIL.
P R O D U C T H I G H L I G H T
I
N I T I A L
O
S C I L L AT O R
A
C C U R A C Y
PA C K A G E O R D E R I N F O R M AT I O N
Plastic Wide SOIC
16-pin
T
J
(°C)
Plastic DIP
16-pin
SG3825CN
SG2825CN
0 to 70
-25 to 85
-55 to 125
MIL-STD-883
DESC
SG3825CDW
SG2825CDW
SG3825CQ
SG2825CQ
SG3825CJ
SG2825CJ
SG1825CJ
SG1825CJ/883B
SG1825CJ/DESC
SG1825CL
SG1825CL/883B
SG1825CL/DESC
N
DW
Plastic LCC
20-pin
Q
Note: All surface-mount packages are available in Tape & Reel. Append the letter "T" to part number. (i.e. SG3825CDWT)
Ceramic DIP
16-pin
J
L
Ceramic LCC
20-pin
H
I G H
- S
P E E D
C
U R R E N T
-M
O D E
PWM
N
O T
R
E C O M M E N D E D
F O R
N
E W
D
E S I G N S
T
H E
I
N F I N I T E
P
O W E R
O F
I
N N O V A T I O N
Copyright 1994
Rev. 1.3 6/96
F O R F U RT H E R I N F O R M AT I O N C A L L ( 7 1 4 ) 8 9 8 - 8 1 2 1
11861 W
ESTERN
A
VENUE
, G
ARDEN
G
ROVE
, CA. 92841
SG1825C/SG2825C/SG3825C
LIN D
OC
#:
1825
1
current limit comparator, logic, and
output drivers. This device can be
used to implement either current-
mode or voltage-mode switching
power supplies. It also is useful as
a series-resonant controller to
frequencies beyond 1MHz. The
SG1825C is specified for operation
over the full military ambient tem-
perature range of -55°C to 125°C.
The SG2825C is characterized for the
industrial range of -25°C to 85°C,
and the SG3825C is selected for the
commercial range of 0°C to 70°C.
0
5
15
10
390
395
400
405
410
Initial Oscillator Accuracy - KHz
P
415
Sample Size = 45
Mean 411.887
Std. Dev. = 4.3
Std. Dev. = 3.8
Sample Size = 279
Mean 401.661