STMicroelectronics STM811MW16F

Overview

STM811MW16F from STMicroelectronics is a precision voltage supervisor IC with active-low reset (RST), manual reset input (MR), and 2.63 V reset threshold, housed in SOT143-4 package. It monitors 2.55–2.70 V supply rails, delivers ≥140 ms reset pulse width, draws only 7 µA typical supply current, and operates from –40 °C to +85 °C - used for reliable power-on reset and push-button recovery in microcontroller-based embedded systems.

For engineers reviewing the STM811MW16F datasheet, STM811MW16F pinout, STM811MW16F application, or STM811MW16F equivalent, key selection criteria include guaranteed RST assertion down to VCC = 1.0 V, MR input with internal 20 kΩ pull-up, immunity to ≤100 ns MR glitches, and compatibility with 3 V/3.3 V logic interfaces in industrial control and IoT edge nodes.

Technical Context

The STM811MW16F implements a precision bandgap-based voltage comparator with hysteresis to detect VCC drops below 2.63 V (±50 mV over temperature), triggering a monostable timer that holds RST low for ≥140 ms after VCC recovers above threshold. Its MR input accepts TTL/CMOS logic levels and features internal debouncing via 0.5 µs propagation delay and 100 ns glitch rejection.

Unlike basic reset ICs, it supports dual reset initiation paths - power-fail detection and user-initiated reset - with both paths asserting the same open-drain/push-pull RST output. The device maintains valid RST output down to VCC = 1.0 V and includes transient immunity circuitry to ignore negative VCC spikes ≤20 µs at 100 mV underdrive.

Key Specifications

Pinout & Package

SOT143-4 (W1) package: 4-pin, surface-mount, lead-free, 2.8 mm × 2.1 mm footprint with 1.92 mm lead pitch. Compatible with standard reflow profiles including peak 260 °C for 30 s.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TRD2T and TPS3808G12QDBVRQ1, the STM811MW16F uniquely balances industrial temperature range, integrated MR, compact SOT143-4 footprint, and proven field reliability - making it optimal for cost-sensitive, non-automotive embedded systems requiring dual-path reset assurance.

Availability

STM811MW16F is available at Aetrix Electronics and suitable for industrial PLCs, smart meters, IoT sensor nodes, and medical handhelds requiring stable component supply across multi-year production cycles.

Supply support for STM811MW16F 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 devices for industrial, automotive, and consumer markets.

The STM8xx series was developed specifically for robust, low-cost power supervision in resource-constrained microcontroller systems - emphasizing precision threshold accuracy, ultra-low ICC, and simplified integration in space-limited PCB layouts.

FAQ

What is the minimum VCC required for the STM811MW16F to assert RST?

The STM811MW16F guarantees RST assertion down to VCC = 1.0 V across its full operating temperature range (–40 °C to +85 °C). Below 1.0 V, the RST output becomes high-impedance; for applications requiring valid reset down to 0 V, a 100 kΩ pull-down resistor is recommended per the datasheet.

Does the MR input require an external pull-up resistor?

No - the MR input includes an internal 20 kΩ pull-up resistor, allowing direct connection of a normally open push-button switch between MR and GND. External pull-up is unnecessary unless specific logic-level translation or stronger drive strength is needed for noise immunity in harsh EMI environments.

Can STM811MW16F be used with a 3.3 V microcontroller that has an active-high reset input?

No - STM811MW16F provides only active-low RST output. For active-high MCU reset inputs, use STM812MW16F (same threshold and package, but active-high RST) or add an inverter buffer. The device does not support configurable reset polarity.

How does the STM811MW16F handle short VCC transients?

The device rejects negative-going VCC transients ≤20 µs in duration when the dip magnitude is ≤100 mV below the 2.63 V threshold. This immunity is achieved via internal comparator hysteresis and timing filtering, eliminating need for external bypass capacitors beyond the standard 0.1 µF VCC-to-GND decoupling capacitor.