STMicroelectronics STEF512PUR

Overview

STEF512PUR from STMicroelectronics is a dual-channel integrated electronic fuse (eFuse) for independent 5 V and 12 V rail protection, featuring factory-trimmed current limits (3 A typ. on 5 V, 4 A typ. on 12 V), integrated 40 mΩ power FETs, per-channel adjustable dV/dt via soft-start pins (SS5/SS12), and precise overvoltage clamping (5.7 V and 15.0 V typ.). It enables hot-swap operation and inrush control in storage and consumer media systems.

For engineers reviewing the STEF512PUR datasheet, STEF512PUR pinout, STEF512PUR application, or STEF512PUR equivalent, this device delivers verified dual-rail fault management with thermal latch-off, UVLO, current monitoring (30 µA/A gain), and QFN10-2x3 mm package integration - critical for SSD/HDD power sequencing and set-top box supply integrity.

Technical Context

The STEF512PUR embeds two independent analog control loops: one for output voltage clamping (via VGS regulation during overvoltage) and one for current limiting (using sense-FET topology to enforce ILim_5 = 3 A and ILim_12 = 4 A). Each channel implements undervoltage lockout (VUVLO_5 = 4.35 V, VUVLO_12 = 9.7 V) with hysteresis (1.78 V / 2 V) and latched thermal shutdown at 165 °C.

Startup behavior is user-programmable via external capacitors on SS5 and SS12, yielding 13 ms (5 V) and 12 ms (12 V) typical dV/dt ramp times (10–90%). Current monitoring outputs IMON_5 and IMON_12 deliver proportional analog currents (AI = 30 µA/A) referenced to GND, requiring external RMON resistors for voltage conversion.

Key Specifications

Pinout & Package

STEF512PUR is housed in a thermally enhanced QFN10 (2 mm × 3 mm, 0.4 mm pitch) package with exposed thermal pad (pin 3 = GND). The 10-pin layout supports dual-rail independence, dedicated monitor outputs, and soft-start configuration without external gate drivers.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-rail eFuse applications.

Compared with TCKE205B and TPS25942L, STEF512PUR provides true hardware-isolated dual-rail protection with independent current limits, per-rail dV/dt tuning, and dedicated monitor outputs - essential for systems requiring deterministic fault containment across mixed-voltage domains.

Availability

STEF512PUR is available at Aetrix Electronics and suitable for SSD power sequencing, HDD hot-swap interfaces, and set-top box multi-rail protection requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for STEF512PUR 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, and automotive-grade ICs with strong focus on industrial reliability and eco-design.

The STEF512PUR belongs to ST's eFuse portfolio designed specifically for high-integrity storage and consumer media power delivery - emphasizing rail independence, thermal robustness, and system-level diagnostics.

FAQ

What is the maximum allowable input voltage for the 5 V and 12 V rails?

The absolute maximum input voltage is 20 V for both VIN_5 and VIN_12 under continuous operation, with brief (≤100 ms) tolerance up to 25 V. Exceeding these ratings risks permanent damage. The device clamps VOUT_5 to 5.9 V max and VOUT_12 to 15.5 V max during overvoltage events, but input overvoltage beyond absolute max still stresses internal FETs.

How does the current monitor output work, and what external components are required?

IMON_5 and IMON_12 deliver 30 µA of current per ampere of respective load current. To convert to measurable voltage, connect an external resistor (e.g., 10 kΩ) between IMON_x and GND. A 1 nF capacitor in parallel filters noise. Output voltage equals IOUT × 30 µA/A × RMON, enabling ADC-compatible sensing without shunt losses.

Can the STEF512PUR automatically recover from thermal shutdown?

No - thermal shutdown is latched. Once junction temperature exceeds 165 °C, the internal FET opens and remains off until EN is toggled low-to-high or the entire supply is cycled. This prevents uncontrolled restart during persistent overloads. Recovery requires explicit host intervention, ensuring fault condition verification before re-enabling.

Is reverse current protection built-in, and what happens if VOUT exceeds VIN?

No reverse current protection is integrated. If VOUT_x rises > VIN_x + 0.3 V for >100 µs, the internal body diode conducts, risking destructive current. ST explicitly warns against DC reverse bias. For such applications, add an external series Schottky diode or select a device with integrated reverse-blocking FET architecture.