STMicroelectronics STM6822MWY6F

Overview

STM6822MWY6F from STMicroelectronics is a 5-pin precision voltage supervisor IC with integrated watchdog timer and manual reset input, designed for microprocessor power-on and brown-out monitoring in industrial embedded systems. It monitors VCC at 3.3 V threshold, provides active-low open-drain RST output, delivers 1.4 ms reset pulse width (typ.), and features 1.6 s watchdog timeout (typ.) with guaranteed RST assertion down to VCC = 1.0 V.

For engineers reviewing the STM6822MWY6F datasheet, STM6822MWY6F pinout, STM6822MWY6F application, or STM6822MWY6F equivalent, this device serves as a low-power (3 µA typ.), temperature-stable (–40 to +85 °C), RoHS-compliant supervisory solution for reliable MCU reset control in space-constrained SOT23-5 designs.

Technical Context

The STM6822MWY6F implements a precision bandgap reference and comparator to detect VCC drop below 3.3 V ±2.5%, asserting RST within 10 µs (typ.) after threshold violation. Its watchdog timer resets on WDI inactivity ≥1.6 s (typ.), cleared by any edge transition - enabling robust recovery from firmware lockup.

It integrates an internal 52 kΩ pull-up on MR and supports open-drain RST with external pull-up (e.g., 10 kΩ), allowing level-shifting across supply domains. Reset remains asserted for trec (1.4 ms typ.) after VCC recovery, MR release, or watchdog timeout - ensuring sufficient deassertion delay for full MCU initialization.

Key Specifications

Pinout & Package

STM6822MWY6F is housed in a standard 5-pin SOT23-5 package (JEDEC MO-178AA), with 1.3 mm height, 2.9 mm × 1.6 mm footprint, and gull-wing leads compatible with automated PCB assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM6823MWY6F, STM6822MWY6F trades push-pull simplicity for open-drain flexibility and multi-supply interoperability; versus TPS3808G33DBVR, it adds critical field-serviceability (MR) and fault-recovery (watchdog) capabilities at modest BOM cost.

Availability

STM6822MWY6F is available at Aetrix Electronics and suitable for industrial PLC controllers, smart metering units, medical diagnostic sensor nodes, and automotive body control modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for STM6822MWY6F 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.

STM6xxx is ST's dedicated microprocessor supervisor product line, engineered to provide robust, low-power, and pin-compatible voltage monitoring and reset generation for resource-constrained embedded systems.

FAQ

What is the exact reset threshold voltage and tolerance for STM6822MWY6F?

The STM6822MWY6F has a nominal VCC reset threshold of 3.3 V with a tolerance of ±2.5% over temperature (–40 to +85 °C) and supply voltage range. This value is factory-trimmed and specified in Table 6 of the official datasheet (DocID11110 Rev 14), ensuring consistent brown-out detection across production lots without external calibration.

Can the watchdog function be disabled, and how?

Yes, the watchdog function is disabled when the WDI pin is left floating or driven by a tristated buffer. In this state, the internal watchdog counter is held inactive, and no reset is generated due to timeout. The datasheet confirms maximum allowable leakage (<10 µA) and capacitance (<200 pF) for reliable disable behavior - no additional components are needed.

Is an external pull-up resistor required on the RST pin, and what value is recommended?

Yes - because STM6822MWY6F features an open-drain RST output, an external pull-up resistor is mandatory. A 10 kΩ resistor to the target reset domain voltage (up to 6 V) is recommended per Figure 11 and Section 2.2 of the datasheet; this value ensures logic-high recognition while limiting sink current to <0.33 mA during assertion.

Does STM6822MWY6F support operation below 1.8 V VCC, and what is the minimum functional voltage?

Yes - STM6822MWY6F guarantees RST assertion functionality down to VCC = 1.0 V at TA = 0 to 85 °C, as explicitly stated in the Features section and Section 2.1. Below 1.0 V, the device may cease operation, but the 1.0 V guarantee ensures fail-safe reset behavior during severe brown-out events common in battery-backed or capacitor-hold-up systems.