STMicroelectronics STM811RW16F

Overview

STM811RW16F from STMicroelectronics is a precision active-low reset supervisor IC with manual reset input (MR), designed for 2.63 V supply monitoring in industrial-grade microprocessor systems. It features a 140 ms minimum reset pulse width, 6 µA typical supply current, guaranteed RST assertion down to VCC = 1.0 V, and SOT143-4 (W1) package. It is used in embedded controllers requiring reliable power-on and push-button reset functionality.

For engineers reviewing the STM811RW16F datasheet, STM811RW16F pinout, STM811RW16F application, or STM811RW16F equivalent, key selection criteria include reset threshold accuracy (2.55–2.70 V), MR input compatibility with TTL/CMOS logic, immunity to sub-100 ns noise on MR, and validity of RST output across –40 °C to 85 °C.

Technical Context

The STM811RW16F integrates a precision voltage comparator with hysteresis, a debounced manual reset input (MR) with internal 20 kΩ pull-up, and a reset timer generating ≥140 ms active-low RST pulses. Its reset threshold is factory-trimmed to 2.63 V (typ) with ±15 mV tolerance over temperature.

It operates from 1.2 V to 5.5 V supply, asserts RST when VCC falls below VRST or MR is pulled low, and holds RST asserted for trec after VCC recovers above VRST. The MR input accepts logic-level signals and supports open-drain drive without external components.

Key Specifications

Pinout & Package

SOT143-4 (W1) package: 4-pin, surface-mount, lead-free, small-outline transistor outline with 1.92 mm lead pitch and 2.80 × 2.10 mm body size.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809R and TPS3808G12, the STM811RW16F uniquely combines fixed 140 ms reset timing, integrated MR with internal pull-up, and compact SOT143-4 packaging-making it optimal for cost-sensitive, space-constrained industrial controls where both power and user-initiated reset are required.

Availability

STM811RW16F is available at Aetrix Electronics and suitable for industrial PLCs, smart energy meters, motor drive control boards, and IoT edge gateways requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for STM811RW16F 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 automotive ICs.

The STM8xx series is ST's industrial-grade reset supervisor product line, engineered specifically for robust power-on reset and manual recovery in harsh electromagnetic and thermal environments.

FAQ

What is the exact reset threshold voltage range for STM811RW16F?

The STM811RW16F has a factory-trimmed reset threshold of 2.55 V to 2.70 V over the full –40 °C to +85 °C operating temperature range, with a typical value of 2.63 V at 25 °C. This range is specified in Table 5 of the official datasheet (Doc ID 9873 Rev 5) and applies under all valid VCC conditions from 1.2 V to 5.5 V.

Can the MR pin be left unconnected without external pull-up?

Yes-the MR pin includes an internal 20 kΩ pull-up resistor to VCC, so it may be left floating if manual reset is not required. When unused, MR defaults high and does not affect RST behavior. No external components are needed, simplifying layout and reducing BOM cost.

Does RST remain valid when VCC drops below 1.0 V?

No-RST output ceases to sink current when VCC falls below 1.0 V and becomes high-impedance. For applications requiring RST to stay asserted down to 0 V, a 100 kΩ pull-down resistor from RST to VSS is recommended per Section 2.4 of the datasheet to maintain low state during deep brown-out.

Is STM811RW16F RoHS-compliant and lead-free?

Yes-STM811RW16F is supplied in an ECOPACK®-compliant, lead-free SOT143-4 package (W1 variant), meeting RoHS Directive 2011/65/EU and REACH SVHC requirements. The "F" suffix in the part number explicitly denotes ECOPACK® tape-and-reel packaging.