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October 2003

s

80m

Ω HIGH-SIDE MOSFET SWITCH

s

500mA CONTINUOUS CURRENT PER

CHANNEL

s

INDEPENDENT THERMAL AND

SHORT-CIRCUIT PROTECTION WITH

OVERCURRENT LOGIC OUTPUT

s

OPERATING RANGE FROM 2.7V TO 5.5V

s

CMOS- AND TTL-COMPATIBLE ENABLE

INPUTS

s

2.5ms TYPICAL RISE TIME

s

UNDERVOLTAGE LOCKOUT

s

10

µA MAXIMUM STANDBY SUPPLY

CURRENT

s

AMBIENT TEMPERATURE RANGE, 0°C TO

85°C

s

ESD PROTECTION

DESCRIPTION

The

ST2042

power

distribution

switches

is

intended for application where heavy capacitive

loads

and

short

circuits

are

likely

to

be

encountered. These devices incorporate 80m

Ω

N-channel MOSFET high-side power switches for

power-distribution systems that require multiple

powers switches in a single package. Each switch

is controlled by an independent logic enable input.

Gate drive is provided by an internal charge pump

designed to control the power-switch rise times

and fall times to minimize current surges during

switching. The charge pump requires no external

components and allows operation from supplies

as low as 2.7 V.

When the output load exceeds the current-limit

threshold or a short is present, these devices limit

the output current to a safe level by switching into

a constant-current mode, pulling the overcurrent

(OCx) logic output low. When continuous heavy

overloads and short circuits increase the power

dissipation in the switch, causing the junction

temperature to rise, a thermal protection circuit

shuts off the switch to prevent damage. Recovery

from a thermal shutdown is automatic once the

device has cooled sufficiently. Internal circuitry

ensures the switch remains off until valid input

voltage

is

present.

These

power-distribution

switches are designed to current limit at 0.9 A

ORDERING CODES

Type

Temperature

Range

Package

Comments

ST2042BD

-40 to 85 °C

SO-8 (Tube)

50parts per tube / 40tube per box

ST2042BDR

-40 to 85 °C

SO-8 (Tape & Reel)

2500 parts per reel

ST2042

CURRENT LIMITED

POWER DISTRIBUTION SWITCHES

SOP