Features
• 5 V and 12 V channels in one chip
• 23.5 V absolute maximum input voltage
• Precise output overvoltage clamp
• Fixed overcurrent protection for both channels
• Reverse current protection on 5 V channel
• Current monitor output in a single pin for both rails
• Current monitor pin selection
• Thermal protection
• Auto-retry after fault
• Input undervoltage lockout
• Integrated 45 mΩ power MOSFETs
• SAS-disable pin
• SATA ignore function
• DFN10 ( 2x3 mm) package

Applications
• HD and SSD
• Hard disk arrays and NAS
• Hot-swap, hot-plug protection

Description
The STEF512SRI is an integrated dual electronic fuse, designed to protect circuitry
on the output from overcurrent and overvoltage events, in those applications
requiring hot-swap operation and in-rush current control.
The device embeds two electronic fuses, one for the 5 V rail and one for the 12 V rail.
Thanks to the very low ON-resistance of the integrated power MOSFETs, the voltage
drop from the main supply to the load is very low during normal operation.
The 5 V channel provides a reverse blocking feature, preventing current flow to the
input in case of brown-out or shutdown.
Startup time is internally controlled by a dedicated slew-rate circuit. In this way, the
in-rush current at startup can be kept under control.
The maximum load current is precisely limited, by utilizing a sense FET topology, to
factory-defined values.
The device also provides precise overvoltage clamp for each channel, preventing
the load from being damaged by power supply failures, and Undervoltage Lockout
(UVLO), assuring that the input voltage is above the minimum operating threshold
before the power device is turned on.
When an overload condition occurs, the STEF512SRI limits the output current to the
predefined safe value. If the anomalous overload condition persists, the device goes
into thermal shutdown, the internal switch opens, and the load is disconnected from
the power supply. The load current on each channel can be precisely monitored by
reading the signal on the IMON_5/12 pin.
The device features a SATA ignore pin (SATAIG) that can be used to simplify
compatibility among SAS/SATA interfaces.