STEF4S Datasheet, PDF (1/22 Pages) STMicroelectronics – Electronic fuse for 3.3 V and 5 V lines

STEF4S
Electronic fuse for 3.3 V and 5 V lines
')1[/
Features
• Power MOSFET on-resistance (typ.): 40 mΩ
• Enable function
• Output clamp voltage (typ.): 5.7 V in 5 V mode,
and 3.8 V in 3.3 V mode
• Undervoltage lockout
• Short-circuit limit
• Overload foldback current limit
• Controlled soft-start
• Thermal auto-retry
• Internal sensing FET
• Operative temp. range: - 40 °C to 85 °C
• Available in DFN 3x3 10L package
Description
The STEF4S is an integrated electronic fuse
optimized for monitoring the output current and
the input voltage. It can be connected in series to
3.3 V or 5 V rails, protecting the electronic
circuitry on its output from overcurrent and
overvoltage. The operating mode (5 V or 3.3 V)
can be selected by a dedicated pin. The STEF4S
has a controlled turn-on time, adjustable by an
external capacitor. When an overload condition
occurs the device limits the output current to a
Datasheet - production data
predefined safe value. If the anomalous overload
condition persists it goes into an open state,
disconnecting the load from the power supply. If a
continuous short-circuit is present on the board,
the E-fuse limits the output current to a safe
value.
In case of overvoltage on the input, the device
clamps the output voltage to a predefined value
and protects the load.
If the anomalous fault condition persists, the
internal thermal protection circuit shuts down the
device and then automatically attempts to re-
supply the load until the fault condition is
removed.
Unlike 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.
Applications
• Hard disk drives
• Solid state drives (SSD)
• Hard disk and SSD arrays
• Set-top boxes
• DVD and blu-ray disc drivers
Table 1. Device summary
Order code
Package
Packing
STEF4SPUR DFN 3x3 - 10L Tape and reel
December 2014
This is information on a product in full production.
DocID025259 Rev 2
1/22
www.st.com