STMicroelectronics STM812TW16F

Overview

STM812TW16F from STMicroelectronics is an industrial-grade active-high reset supervisor IC with manual reset input, designed for 3.0 V supply monitoring in microprocessor-based systems. It features a precision 3.00–3.15 V reset threshold, 140 ms minimum reset pulse width, 6 µA typical supply current, and guaranteed RST assertion down to VCC = 1.0 V - deployed in embedded controllers requiring reliable power-on and brownout reset signaling.

For engineers reviewing the STM812TW16F datasheet, STM812TW16F pinout, STM812TW16F application, or STM812TW16F equivalent, key selection considerations include its SOT143-4 package, push-button MR input with internal 20 kΩ pull-up, immunity to sub-100 mV/20 µs VCC transients, and compatibility with 3.0 V logic-level MCUs across –40 °C to +85 °C operation.

Technical Context

The STM812TW16F implements a voltage-monitoring comparator with hysteresis and an internal debounce timer to generate a clean, glitch-immune reset pulse. Its reset output (RST) is active-high and push-pull, sourcing/sinking up to 500 µA (VOH) and sinking 1.2 mA (VOL), with valid operation down to VCC = 1.0 V at industrial temperature range.

It integrates a dedicated manual reset input (MR) with TTL/CMOS-compatible thresholds, internal 20 kΩ pull-up, and 100 ns glitch immunity. The device asserts RST immediately on MR low and holds it for trec (140–280 ms) after MR returns high - eliminating need for external debouncing circuitry in most applications.

Key Specifications

Pinout & Package

SOT143-4 (W1) package: 4-pin, lead-free, small-outline transistor outline with 1.92 mm pitch, optimized for high-density PCB layouts and automated assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TRD3 and TPS3808G33DBVR, the STM812TW16F uniquely combines 3.0 V precision monitoring, integrated MR input, active-high push-pull RST, and industrial temperature support in a compact SOT143-4 package - making it optimal for space-constrained 3.0 V embedded systems requiring field-reset capability.

Availability

STM812TW16F is available at Aetrix Electronics and suitable for industrial PLC controllers, smart energy meters, automotive body control modules, and medical handheld diagnostics requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for STM812TW16F 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, delivering intelligent power, sensing, and control solutions for industrial, automotive, and consumer markets.

The STM8xx series is ST's dedicated family of low-power voltage supervisors targeting microprocessor reset management - engineered for precision threshold accuracy, minimal quiescent current, and robust noise immunity in harsh operating environments.

FAQ

What is the exact reset threshold voltage range for STM812TW16F?

The STM812TW16F has a guaranteed reset threshold of 3.00 V to 3.15 V over the full –40 °C to +85 °C temperature range, with a typical value of 3.08 V at 25 °C. This range is specifically calibrated for 3.0 V supply monitoring and is confirmed in Table 5 of the official STMicroelectronics datasheet (Doc ID 9873 Rev 5).

Does STM812TW16F require an external pull-up resistor on the MR pin?

No. The MR pin includes an internal 10–30 kΩ pull-up resistor (20 kΩ typical), allowing direct connection of a normally open push-button switch between MR and GND. External pull-up is unnecessary unless enhanced noise immunity is required - in which case a 0.1 µF capacitor from MR to GND is recommended per Section 2.2 of the datasheet.

Can STM812TW16F drive a reset pin that requires 10 mA sink current?

No. The STM812TW16F RST output is rated for 1.2 mA sink (VOL @ IOL = 1.2 mA) and 500 µA source (VOH @ IOH = 500 µA). Driving 10 mA would exceed specifications and risk output failure. For higher-current loads, an external NPN transistor or buffer stage is required - as noted in the "RST output" section (2.1) of the datasheet.

Is STM812TW16F compatible with 1.8 V microcontrollers?

No. While the device operates down to VCC = 1.2 V, its RST output high voltage (VOH) is specified as 0.8 × VCC only when VCC > VRST (min); at 1.8 V supply, VOH ≈ 1.44 V - insufficient to meet standard 1.8 V CMOS VIH (typically ≥ 1.62 V). It is designed for 3.0 V systems, as confirmed by its T (3.0 V) threshold variant and application examples in the datasheet.