STMicroelectronics STM1001LWX6F

Overview

STM1001LWX6F from STMicroelectronics is a precision voltage supervisor IC designed to monitor 3.3 V supply rails in microprocessor-based systems, asserting an open-drain active-low reset signal (RST) when VCC drops below 4.63 V (typ), with guaranteed operation down to VCC = 1.0 V, 30 ms minimum reset pulse width, and 6 µA typical supply current. It serves as a system-level power-on reset and brownout detector in industrial embedded controllers.

For engineers reviewing the STM1001LWX6F datasheet, STM1001LWX6F pinout, STM1001LWX6F application, or STM1001LWX6F equivalent, key selection criteria include reset threshold accuracy (±2.5% over –40 °C to +85 °C), immunity to sub-20 µs VCC transients, SOT23-3 footprint compatibility, and guaranteed RST assertion at ultra-low VCC for fail-safe MCU initialization.

Technical Context

The STM1001LWX6F implements a precision bandgap-based voltage reference comparator with hysteresis, driving a monostable timer that generates a fixed-duration reset pulse upon power-up or brownout recovery. Its internal reset timeout (trec) is factory-set to 30 ms (min), with no external components required.

It features a dedicated open-drain RST output requiring an external pull-up resistor, supports operation across the full industrial temperature range (–40 °C to +85 °C), and maintains valid reset assertion even as VCC collapses to 1.0 V - enabling robust reset behavior during deep undervoltage conditions.

Key Specifications

Pinout & Package

SOT23-3 (WX) package: 3-pin, surface-mount, lead-free, 2.8 mm × 2.1 mm footprint with 0.95 mm pitch; compatible with standard reflow profiles including peak 260 °C (≤30 s above 255 °C).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervisor applications.

Compared with MAX809LTR and TPS3808G33DBVR, the STM1001LWX6F uniquely combines precise 4.63 V threshold targeting 3.3 V rail margin, 30 ms trec optimized for modern MCUs, and 6 µA ICC - making it optimal for industrial systems requiring fast, low-power, and accurate brownout response.

Availability

STM1001LWX6F is available at Aetrix Electronics and suitable for industrial PLCs, smart energy meters, network edge routers, and factory automation gateways requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for STM1001LWX6F 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 analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The STM1001 belongs to ST's precision voltage supervisor product line, engineered specifically for industrial-grade power monitoring with emphasis on low ICC, wide VCC range, and robust transient immunity in harsh environments.

FAQ

What is the exact reset threshold voltage for STM1001LWX6F, and how does it vary with temperature?

The STM1001LWX6F has a nominal reset threshold of 4.63 V at 25 °C, with a guaranteed range of 4.50 V to 4.75 V across –40 °C to +85 °C. Its temperature coefficient is 45 ppm/°C, resulting in ≤±0.3% threshold drift over the full industrial temperature range - verified per Table 4 and Figure 9 in the official datasheet.

Does STM1001LWX6F require an external pull-up resistor on the RST pin, and what value is recommended?

Yes, the RST pin is open-drain and requires an external pull-up resistor. A 10 kΩ resistor to the target logic supply (e.g., 3.3 V) is typical, delivering ~330 µA sink current at VOL = 0.3 V (per Table 4). Values from 4.7 kΩ to 100 kΩ are acceptable depending on rise time and bus loading requirements.

Can STM1001LWX6F monitor a 3.3 V supply while operating from a separate 5 V rail?

No - the device monitors its own VCC pin. To supervise a 3.3 V rail, VCC must be connected directly to that rail. It cannot monitor a voltage different from its supply; there is no independent sense input. This is confirmed by the block diagram (Figure 3) and "VCC Supply Voltage" parameter in Table 4.

Is STM1001LWX6F pin-compatible with earlier STM6301 variants?

Yes - the STM1001 is a direct functional successor to the STM6301, sharing identical SOT23-3 pinout (VCC–RST–VSS), electrical characteristics, and marking format. The revision history (Table 8) confirms the part number change occurred in Rev 2 (Feb 2004), with no mechanical or functional divergence.