STEF12 Datasheet, PDF (1/20 Pages) STMicroelectronics – Electronic fuse for 12 V line

STEF12
Electronic fuse for 12 V line
Features
■ Continuous current (typ): 3.6 A
■ N-channel on-resistance (typ): 53 mΩ
■ Enable/Fault functions
■ Output clamp voltage (typ):15 V
■ Undervoltage lockout
■ Short-circuit limit
■ Overload current limit
■ Controlled output voltage ramp
■ Thermal latch (typ): 165 °C
■ Uses tiny capacitors
■ Operating junction temp. - 40 °C to 125 °C
■ Available in DFN10 (3 x 3 mm) package
Applications
■ Hard disk drives
■ Solid state drives (SSD)
■ Hard disk and SSD arrays
■ Set-top boxes
■ DVD and Blu-Ray disc drivers
Description
The STEF12 is an integrated electronic fuse
optimized for monitoring output current and input
voltage. Connected in series to a 12 V rail, it is
capable of protecting the electronic circuitry on its
output from overcurrent and overvoltage. The
device has a controlled delay and turn-on time.
When an overload condition occurs, the STEF12
limits the output current to a predefined safe
value. If the anomalous overload condition
DFN10 (3 x 3 mm)
persists it goes into an open state, disconnecting
the load from the power supply. If a continuous
short-circuit is present on the board, when power
is re-applied the E-fuse initially limits the output
current to a safe value and then again goes into
an open state. The device is equipped with a
thermal protection circuit. The intervention of the
thermal protection is signalled to the board
monitoring circuits through a signal on the Fault
pin. Unlike the mechanical fuses, which must be
physically replaced after a single event, the E-
fuse does not degrade in its performance after
short-circuit/thermal protection interventions and
it is reset either by recycling the supply voltage or
using the Enable pin. The companion chip for the
5 V power rails is also available with part number
STEF05.
Table 1. Device summary
Order code
Package
Packaging
STEF12PUR
DFN10 (3 x 3 mm)
Tape and reel
December 2011
Doc ID 019056 Rev 3
1/20
www.st.com
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