SG1842 Datasheet, PDF (1/14 Pages) Microsemi Corporation – CURRENT MODE PWM CONTROLLER

THE IN F I N I T E P O W E R OF IN N O VAT I O N
L I N D O C # : 1842
SG1842/SG1843 Series
CURRENT MODE PWM CONTROLLER
PRODUCTION DATA SHEET
DESCRIPTION
The SG1842/43 family of control IC's
provides all the necessary features to
implement off-line fixed frequency,
current-mode switching power supplies
with a minimum number of external
components. Current-mode
architecture demonstrates improved
line regulation, improved load
regulation, pulse-by-pulse current
limiting and inherent protection of the
power supply output switch.
The bandgap reference is trimmed to
±1% over temperature. Oscillator
discharge current is trimmed to less
than ±10%. The SG1842/43 has under-
voltage lockout, current limiting
circuitry and start-up current of less
than 1mA.
The totem-pole output is optimized
to drive the gate of a power MOSFET.
The output is low in the off state to
provide direct interface to an N
channel device.
The SG1842/43 is specified for
operation over the full military ambient
temperature range of -55°C to 125°C.
The SG2842/43 is specified for the
industrial range of -25°C to 85°C, and
the SG3842/43 is designed for the
commercial range of 0°C to 70°C.
PRODUCT HIGHLIGHT
TYPICAL APPLICATION OF SG3842 IN A FLYBACK CONVERTER
AC
INPUT
R_ST
I_ST
V_CC
SG3842
KEY FEATURES
s OPTIMIZED FOR OFF-LINE CONTROL
s LOW START-UP CURRENT (<1mA)
s AUTOMATIC FEED FORWARD
COMPENSATION
s TRIMMED OSCILLATOR DISCHARGE
CURRENT
s PULSE-BY-PULSE CURRENT LIMITING
s ENHANCED LOAD RESPONSE
CHARACTERISTICS
s UNDER-VOLTAGE LOCKOUT WITH 6V
HYSTERESIS (SG1842 only)
s DOUBLE-PULSE SUPPRESSION
s HIGH-CURRENT TOTEM-POLE OUTPUT
(1AMP PEAK)
s INTERNALLY TRIMMED BANDGAP
REFERENCE
s 500KHZ OPERATION
s UNDERVOLTAGE LOCKOUT
SG1842 - 16 volts
SG1843 - 8.4 volts
s LOW SHOOT-THROUGH CURRENT <75mA
OVER TEMPERATURE
HIGH RELIABILITY FEATURES
s AVAILABLE TO MIL-STD-883B AND DESC
SMD
s SCHEDULED FOR MIL-M38510 QPL LISTING
s RADIATION DATA AVAILABLE
s LINFINITY LEVEL "S" PROCESSING AVAILABLE
T_A (°C)
M
Plastic DIP
8-pin
0 to 70
SG3842M
SG3843M
-25 to 85
SG2842M
SG2843M
—
-55 to 125
—
—
MIL-STD/883
—
—
DESC
PACKAGE ORDER INFORMATION
N
Plastic DIP
14-pin
DM
Plastic
8-pin
SOIC
D
Plastic SOIC
14-pin
Y
Ceramic DIP
8-pin
J
Ceramic DIP
14-pin
F
Cer. Flatpack
10-pin
L
Ceramic LCC
20-pin
SG3842N
SG3842DM
SG3842D
SG3842Y
SG3842J
—
—
SG3843N
SG3843DM
SG3843D
SG3843Y
SG3843J
—
—
SG2842N
SG2842DM
SG2842D
SG2842Y
SG2842J
—
—
SG2843N
SG2843DM
SG2843D
SG2843Y
SG2843J
—
—
—
—
—
SG1842Y
SG1842J
—
SG1842L
—
—
—
SG1843Y
SG1843J
—
SG1843L
—
—
—
SG1842Y/883B SG1842J/883B
—
SG1842L/883B
—
—
—
SG1843Y/883B SG1843J/883B
—
SG1843L/883B
—
—
—
SG1842Y/DESC SG1842J/DESC SG1842F/DESC SG1842L/DESC
—
—
SG1843Y/DESC SG1843J/DESC SG1843F/DESC SG1843L/DESC
Note: All surface-mount packages are available in Tape & Reel.
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Copyright © 2000
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1
Rev. 1.6 4/00