May 2007

Rev 5

1/13

13

Features

protection with overcurrent logic output

Description

The ST2044 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.

SO-16

ST2044

Current limited

Power distribution switches

www.st.com

Table 1.

Device summary

Part number

Package

Packaging

ST2044BD

SO-16

Tube

(50 parts per tube, 40 tube per box)

ST2044BDR

SO-16

Tape and reel (2500 parts per reel)