STMicroelectronics STMPS2151STR

Overview

STMPS2151STR from STMicroelectronics is a 500 mA active-high enable, high-side N-channel MOSFET power switch with integrated thermal and short-circuit protection, 90 mW R_ON at 5 V, 2.7–5.5 V operating range, and open-drain FAULT output - used for hot-swap-capable USB peripheral power distribution in embedded industrial controllers.

For engineers reviewing the STMPS2151STR datasheet, STMPS2151STR pinout, STMPS2151STR application, or STMPS2151STR equivalent, key selection criteria include enable polarity, current limit accuracy (120% of rated 500 mA), fault blanking duration (10 ms), reverse current blocking behavior, and thermal shutdown recovery characteristics.

Technical Context

The STMPS2151STR implements a single-channel high-side power switch with CMOS/TTL-compatible active-high EN input and open-drain FAULT output. Its internal protection logic responds to overcurrent (via constant-current limiting), die overtemperature (>135 °C), and undervoltage (UVLO threshold ~2.4 V rising, ~2.1 V falling).

Fault blanking applies exclusively to overcurrent events for 10 ms (typ.), suppressing false FAULT assertions during capacitive load inrush or hot-swap transients; UVLO and overtemperature faults trigger FAULT immediately without blanking.

Key Specifications

Pinout & Package

SOT23-5L package: compact 5-pin surface-mount outline with exposed pad for thermal enhancement; footprint compatible with JEDEC MO-178AB standard.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-side power switch applications.

Compared with TCK107AG and TPS22922DRLR, the STMPS2151STR uniquely combines fault blanking, UVLO, and UL recognition in a SOT23-5L package - making it optimal for safety-critical, hot-swap industrial power rails where diagnostics and regulatory compliance are mandatory.

Availability

STMPS2151STR is available at Aetrix Electronics and suitable for USB peripheral power control, industrial I/O module protection, and embedded system rail sequencing requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for STMPS2151STR 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, microcontrollers, and automotive-grade ICs with broad industrial qualification.

The STMPS series targets robust, low-cost power distribution in space-constrained industrial and embedded systems - designed specifically for hot-swap resilience, fault diagnostics, and regulatory compliance without external components.

FAQ

What is the function of the FAULT pin, and how does fault blanking affect its behavior?

The FAULT pin is an open-drain, active-low indicator that asserts only after overcurrent or overtemperature conditions persist beyond their respective detection windows. For overcurrent, a 10 ms blanking period prevents false triggering during hot-swap inrush; UVLO and overtemperature faults assert FAULT immediately. The pin requires an external pull-up resistor to function correctly in the host system.

Can the STMPS2151STR safely block reverse current when the output voltage exceeds the input voltage?

Yes - when disabled (EN low) or unpowered (V_IN = 0 V), the device presents a high-impedance state at the OUT pin, preventing reverse current flow from V_OUT to V_IN. However, if the switch is enabled and V_OUT > V_IN, reverse current will flow through the body diode; this condition is explicitly prohibited per the datasheet and may cause damage.

How does the thermal shutdown mechanism recover, and is external intervention required?

Recovery is fully automatic: when junction temperature exceeds 135 °C, the switch turns off and FAULT asserts; once the die cools below 125 °C (10 °C hysteresis), the device resumes normal operation if EN remains high and VIN is within UVLO limits. No external reset or power cycle is needed, enabling self-healing behavior in thermally intermittent environments.

What is the maximum allowable output capacitance before turn-on inrush violates current-limit specifications?

Based on typical 10 µs turn-on time and 600 mA peak current limit (120% of 500 mA), the maximum safe output capacitance is approximately 60 µF for a 5 V rail - calculated using I_peak ≈ C × dV/dt. Larger capacitors require external inrush limiting (e.g., series resistor or soft-start circuit) to avoid repeated current-limit cycling during power-up.