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July 2005

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80m

Ω HIGH-SIDE MOSFET SWITCH

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500mA CONTINUOUS CURRENT PER

CHANNEL

I

INDEPENDENT THERMAL AND

SHORT-CIRCUIT PROTECTION WITH

OVERCURRENT LOGIC OUTPUT

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OPERATING RANGE FROM 2.7V TO 5.5V

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CMOS- AND TTL-COMPATIBLE ENABLE

INPUTS

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10 ms OC_N FAULT BLANKING

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2.5ms TYPICAL RISE TIME

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UNDERVOLTAGE LOCKOUT

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20

µA MAXIMUM STANDBY SUPPLY

CURRENT

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AMBIENT TEMPERATURE RANGE, 0°C TO

85°C

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ESD PROTECTION

DESCRIPTION

The

ST2054

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. A 10ms deglitching circuit

provides fault-blanking feature, preventing the

OC_N pin to be asserted during hot-insertion or

short spikes of overcurrent conditions.

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.

Table 1: Order Codes

Type

Temperature

Range

Package

Comments

ST2054BD

-40 to 85 °C

SO-16 (Tube)

50parts per tube / 40tube per box

ST2054BDR

-40 to 85 °C

SO-16 (Tape & Reel)

2500 parts per reel

ST2054

CURRENT LIMITED

POWER DISTRIBUTION SWITCHES

SOP

Rev. 3