STEF512SRDBPUR [STMicroelectronics]

The STEF512SRDB 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 brownout or shutdown.

The start-up time of each eFuse can be adjusted by the user, via two small soft-start capacitors, connected to the relevant pins. 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 being damaged from 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 STEF512SRDB limits the output current to the predefined safe value. If the anomalous overload condition persists, the device goes into thermal shutdown, the internal switch is open and the load is disconnected from the power supply. 5 V fixed LDO is available to supply external load up to 10 mA.

• 5 V and 12 V channels into one chip
• 25 V absolute maximum input voltage
• Precise output overvoltage clamp
• Fixed overcurrent protection trip points
• Fast reverse current protection on 5 V channel
• Thermal protection
• Latch-off thermal protection
• Input undervoltage lockout
• Adjustable output voltage slew rate for each channel by external capacitors
• Integrated 40 mΩ power MOSFETs
• 100 ms safety start-up delay
• SAS disable and enable pins
• 5 V embedded LDO
• - 3 V transient protection
• DFN10 (2 x 3 mm) package