STMicroelectronics STEF01FTR

Overview

STEF01FTR from STMicroelectronics is a fully programmable universal electronic fuse in HTSSOP14 package, designed for series insertion in DC power rails (8–48 V) to monitor and protect against overcurrent, overvoltage, and thermal faults. It delivers 4 A continuous current with 30 mΩ typical R_DS(on), adjustable output clamp (10–52 V), and supports hot-swap operation in telecom and industrial power modules.

For engineers reviewing the STEF01FTR datasheet, STEF01FTR pinout, STEF01FTR application, or STEF01FTR equivalent, key selection considerations include programmable UVLO threshold (8–45 V), dual-mode thermal protection (latch/auto-retry), external reverse-current MOSFET gate drive, soft-start timing control via dv/dt capacitor, and Power Good flag signaling.

Technical Context

The STEF01FTR integrates an N-channel power MOSFET with precision current sensing using a Sense FET architecture, enabling foldback current limiting (1.5 A short-circuit, 4 A overload) based on external R_Limit. Its overvoltage clamp circuit operates independently of input voltage slew rate and responds within microseconds when V_IN exceeds the user-set V_Clamp threshold.

Thermal management combines two coordinated protections: maximum power dissipation limiting (fast-acting, auto-retry only) and junction temperature shutdown (175 °C, configurable latch/auto-retry via Auto pin). The EN/Fault pin serves as tri-state interface-enabling device control, fault signaling (1.4 V intermediate state for thermal latch, 0 V for auto-retry), and inter-device synchronization.

Key Specifications

Pinout & Package

HTSSOP14 package with exposed pad connected internally to V_CC; 4.4 mm × 5 mm footprint, 0.65 mm pitch, suitable for automated assembly and thermal relief via PCB copper pour under exposed pad.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar electronic fuse applications.

Compared with TPS25982L and MP5418, STEF01FTR uniquely combines adjustable overvoltage clamp (10–52 V), dedicated Vg driver for reverse-current blocking, and dual-mode thermal protection-all in a single HTSSOP14 package validated to UL2367 and IEC 62368-1.

Availability

STEF01FTR is available at Aetrix Electronics and suitable for hot-swap power distribution, industrial alarm/lighting systems, and telecom power modules requiring stable component supply, long-term lifecycle support, and safety-certified protection ICs.

Supply support for STEF01FTR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, specializing in power management, analog, microcontrollers, and automotive ICs with strong industrial and telecom focus.

The STEF01 product line delivers programmable electronic fuses for DC power rail protection-designed specifically for hot-swap, distributed power, and safety-critical industrial systems demanding configurability, reliability, and regulatory compliance.

FAQ

What is the minimum R_Limit resistor value supported for reliable current limiting?

The R_Limit resistor must be ≥8 Ω per datasheet Table 3. Using values below 8 Ω risks malfunction of the current-limiting circuit and potential device damage due to uncontrolled sense-FET biasing. Typical design uses 11–22 Ω to achieve 3.2–4.8 A overload limit while maintaining stability across temperature.

How does the STEF01FTR behave during a short-circuit event?

Upon short-circuit detection, it first enters foldback current limiting (1.5 A typ. with R_Limit = 22 Ω), then triggers maximum power protection if dissipation exceeds safe limits, followed by thermal shutdown at 175 °C. Fault status appears on EN/Fault pin as 0 V (auto-retry) or 1.4 V (latch), depending on Auto pin configuration.

Can the Vclamp function protect against fast transients like ESD or lightning surges?

No-the Vclamp circuit responds to sustained overvoltage conditions (ms-scale), not nanosecond transients. For ESD (2 kV HBM) and surge immunity, external TVS diodes remain essential. The Vclamp is intended for slower overvoltage events such as regulator failure or incorrect supply connection.

Is the exposed pad electrically isolated or connected internally?

The exposed pad is electrically connected to V_CC (pin 14) and forms the internal drain node of the power MOSFET. It must be soldered to a PCB copper pour tied to the main 8–48 V rail-not left floating-to ensure both thermal performance (R_thJC = 4 °C/W) and correct device operation.