STMicroelectronics STM1813MWX7F

Overview

STM1813MWX7F from STMicroelectronics is a low-power, open-drain active-low reset IC with manual reset detect functionality, designed for 5 V supply monitoring in microcontroller systems. It features a factory-trimmed 4.37 V reset threshold (±2.5% accuracy), 100 ms minimum reset pulse width, 4 µA typical supply current, and guaranteed operation down to VCC = 1.0 V over –40 °C to +105 °C. It is used in portable embedded systems requiring reliable power-on reset and user-initiated reset via mechanical push-button.

For engineers reviewing the STM1813MWX7F datasheet, STM1813MWX7F pinout, STM1813MWX7F application, or STM1813MWX7F equivalent, this page delivers verified technical context, SOT23-3 package mapping, manual reset debounce timing (≥1.5 µs detection), internal 5.5 kΩ pull-up resistor, and compatibility with DS181x/MXD181x families - all critical for brownout protection and bidirectional MCU reset interface design.

Technical Context

The STM1813MWX7F integrates a precision voltage reference, comparator, and reset timer to monitor VCC and assert RST when voltage falls below 4.37 V (typ.) or when RST is externally pulled low for ≥1.5 µs. Its open-drain output includes an internal 5.5 kΩ pull-up to VCC, enabling direct connection to bidirectional MCU reset pins without external components.

It provides immunity to fast VCC transients (e.g., ≤20 µs at 100 mV overdrive) and guarantees valid reset assertion down to VCC = 1.0 V across full temperature range. The 100 ms reset timeout (trec) is internally generated and independent of external RC networks.

Key Specifications

Pinout & Package

STM1813MWX7F is housed in a 3-pin SOT23-3 (WX) package - a surface-mount, space-saving outline with gull-wing leads, JEDEC MO-178 compliant, footprint compatible with standard SOT-23 pick-and-place equipment.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809SEUR+T and TPS3808G125DBVR, STM1813MWX7F uniquely combines fixed 4.37 V precision monitoring, integrated push-button detect, and internal pull-up in SOT23-3 - delivering lower system-level BOM cost and higher noise immunity for dedicated 5 V reset applications.

Availability

STM1813MWX7F is available at Aetrix Electronics and suitable for industrial PLCs, portable medical monitors, smart energy meters, and automotive BCM subsystems requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for STM1813MWX7F 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, specializing in microcontrollers, power management, analog, and sensor solutions for industrial, automotive, and consumer markets.

STM181x is ST's low-power reset supervisor product line, engineered for high-accuracy supply monitoring and robust reset generation in space-constrained, battery-sensitive embedded systems - with emphasis on ease of integration and transient immunity.

FAQ

Does STM1813MWX7F require an external pull-up resistor on the RST pin?

No. STM1813MWX7F includes an internal 5.5 kΩ pull-up resistor to VCC on the RST pin, enabling direct connection to bidirectional MCU reset inputs without external components. This feature eliminates one passive part, reduces PCB area, and improves reliability in high-vibration environments where solder joints may fatigue.

What is the minimum external push-button pulse width that triggers reset?

The STM1813MWX7F detects manual reset when the RST pin is pulled low for ≥1.5 µs. Pulses shorter than this duration will not initiate the 100 ms reset timeout. This threshold is implemented in hardware and provides inherent debounce against mechanical switch bounce, eliminating the need for external RC filters or firmware debouncing logic.

Can STM1813MWX7F operate reliably during a 5 V supply drop to 1.2 V?

Yes. STM1813MWX7F guarantees valid reset assertion down to VCC = 1.0 V across its full operating temperature range (–40 °C to +105 °C). At 1.2 V, it continues to monitor VCC, assert RST correctly, and maintain internal timing - ensuring deterministic MCU reset behavior during severe brownout conditions common in automotive and industrial power systems.

Is STM1813MWX7F pin-compatible with DS1813?

Yes. STM1813MWX7F is fully compatible with Maxim DS1813 in pinout (SOT23-3), function (open-drain active-low with manual reset detect), and electrical specifications (4.63 V threshold for DS1813 vs. 4.37 V for STM1813MWX7F). While threshold differs, both share identical RST/VCC/VSS pin assignments, timing behavior, and internal pull-up value - enabling drop-in replacement where threshold margin permits.