STMicroelectronics STEC01PUR

Overview

STEC01PUR from STMicroelectronics is a programmable low-side N-channel power switch IC with integrated 12 mΩ R_DS(on) MOSFET, 7 A continuous current capability, and three independent timers (T1 up to 20480 s, T2 fixed at 285 ms, T3 at 69/345/1380 s) for ground-path safety control in high-current battery-powered actuators - deployed in electronic cigarettes to enforce user-defined heater on-time limits and thermal cooldown windows.

For engineers reviewing the STEC01PUR datasheet, STEC01PUR pinout, STEC01PUR application, or STEC01PUR equivalent, this device requires attention to PWM timing compliance (4 Hz–5 kHz, ≥30% duty cycle), T1/T3 resistor-programmed oscillator (TPF pin), HW_RESET debounced edge detection, and GDRV-driven external MOSFET support for >7 A loads.

Technical Context

The STEC01PUR implements a state-machine-based safety controller that monitors PWM activity to initiate T1 (programmable on-time), triggers T2 (285 ms fixed) upon PWM cessation to confirm end-of-cycle, and enforces T3 (user-selectable cooling window) after fault detection. It uses dual oscillator sources: one programmable via TPF resistor (100–400 kHz), one fixed for T2.

Its internal 12 mΩ N-channel MOSFET operates as a low-side switch between PWR (drain) and PGND (source), while GDRV provides gate drive for external N-MOSFETs. Fault response includes immediate SF turn-off, 57 ms open-drain RESET/FAULT pulse, and mandatory PWM low-level hold (>285 ms) before T3 initiation.

Key Specifications

Pinout & Package

VFQFPN 3×3×0.9 mm, 16-lead, 0.5 mm pitch package with exposed thermal pad (GND EXP) for enhanced heat dissipation; RoHS-compliant ECOPACK2 grade.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar programmable low-side safety switch applications.

Compared with NCP380LSN35T2G and BTS50085-1TAD, STEC01PUR uniquely integrates programmable multi-stage timing (T1/T2/T3) specifically for battery-powered thermal safety, enabling precise on-time enforcement and mandatory cooldown - features absent in fixed-protection or high-side automotive switches.

Availability

STEC01PUR is available at Aetrix Electronics and suitable for electronic cigarette manufacturing, USB-aware portable medical devices, inductive actuator control modules, and cordless power tool thermal management systems requiring stable component supply and long-term lifecycle support.

Supply support for STEC01PUR 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, Switzerland, designing and manufacturing microcontrollers, power management ICs, sensors, and analog components for industrial, automotive, and consumer markets.

STEC01PUR belongs to ST's dedicated safety power switch product line, engineered for battery-powered portable devices requiring programmable thermal and timing-based protection - especially where regulatory compliance (e.g., IEC 62368-1) mandates enforced cooldown intervals and user-actuated on-time limits.

FAQ

What is the minimum PWM pulse width required to reliably trigger the STEC01PUR?

The datasheet specifies a minimum PWM high time (t_{PWM_HI}) of 40 µs. This ensures the internal logic detects the rising edge and initiates T1 before the pulse ends. Shorter pulses may fail to register, especially under temperature extremes or voltage variations, leading to inconsistent activation.

Can the STEC01PUR drive an external MOSFET for loads exceeding 7 A, and what are the GDRV voltage limits?

Yes - GDRV outputs a rail-to-rail signal referenced to PGND, with high-side resistance of 30 Ω and low-side resistance of 8 Ω. Its absolute maximum rating is V_GBAT + 0.3 V, allowing direct drive of N-channel MOSFETs with V_GS up to ~5.3 V when V_BAT = 5 V. External gate resistors are recommended for EMI control and ringing suppression.

How does the STEC01PUR distinguish between normal PWM cessation and a fault condition?

It uses T2 (285 ms fixed timer): if PWM goes low and stays low longer than T2, the device enters idle mode normally. If PWM remains high past the programmed T1 duration, it triggers fault mode - turning off SF, asserting RESET/FAULT, and initiating T3 cooldown. T2 expiration alone does not cause fault; only T1 overrun does.

Is the TPF pin sensitive to PCB layout or capacitor loading, and what tolerance resistor is recommended?

Yes - TPF is a high-impedance oscillator programming node. Layout must minimize trace length and avoid nearby noisy signals or capacitive coupling. A 1% tolerance metal-film resistor is recommended; values from 91 kΩ to 400 kΩ set T1 within datasheet-specified min/max bounds, with tighter tolerance improving timer accuracy across temperature.