Copyright © 2000

Rev. 1.6

4/00

FOR FUR THER INFORMA TION CALL (714) 898-8121

1

OF

SG1842/SG1843 Series

DESCRIPTION

KEY FEA TURES

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

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-

PRODUCT HIGHLIGHT

P A CKAGE O RDER I NFORMA TION

T

0 to 70

SG3842M

SG3842N

SG3842DM

SG3842D

SG3842Y

SG3842J

—

—

SG3843M

SG3843N

SG3843DM

SG3843D

SG3843Y

SG3843J

—

—

-25 to 85

SG2842M

SG2842N

SG2842DM

SG2842D

SG2842Y

SG2842J

—

—

SG2843M

SG2843N

SG2843DM

SG2843D

SG2843Y

SG2843J

—

—

-55 to 125

—

—

—

—

SG1842Y

SG1842J

—

SG1842L

—

—

—

—

SG1843Y

SG1843J

—

SG1843L

MIL-STD/883

—

—

—

—

SG1842Y/883B SG1842J/883B

—

SG1842L/883B

—

—

—

—

SG1843Y/883B SG1843J/883B

—

SG1843L/883B

DESC

—

—

—

—

SG1842Y/DESC SG1842J/DESC

SG1842F/DESC SG1842L/DESC

—

—

SG1843Y/DESC SG1843J/DESC

SG1843F/DESC SG1843L/DESC

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

Note: All surface-mount packages are available in Tape & Reel.

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.

Plastic DIP

8-pin

M

Plastic DIP

14-pin

N

Plastic SOIC

8-pin

DM

Plastic SOIC

14-pin

D

Ceramic DIP

8-pin

Y

Ceramic DIP

14-pin

J

Cer. Flatpack

10-pin

F

Ceramic LCC

20-pin

L

AC

INPUT

SG3842

R

ST

I

ST

V

CC