STMicroelectronics STM6322SWY6F

Overview

STM6322SWY6F from STMicroelectronics is a 5-pin precision voltage supervisor IC with integrated watchdog timer and manual reset input, designed for microprocessor reset management in industrial embedded systems. It monitors VCC at 3.3 V (±2.5%), asserts active-low open-drain RST for ≥1.4 ms upon fault, supports MR-triggered reset with internal 52 kΩ pull-up, and delivers 3 µA typical supply current across –40 to +85 °C operation.

For engineers reviewing the STM6322SWY6F datasheet, STM6322SWY6F pinout, STM6322SWY6F application, or STM6322SWY6F equivalent, this page provides verified functional identity, validated SOT23-5 pin mapping, confirmed watchdog timeout (1.6 s), reset threshold accuracy (±2.5%), and real-world interface guidance for MCU reset line contention mitigation and multi-supply open-drain RST termination.

Technical Context

The STM6322SWY6F implements a precision bandgap reference and comparator to monitor VCC against a fixed 3.3 V threshold (±2.5% over temperature). Its watchdog timer triggers reset if WDI remains static for ≥1.6 s (typ.), and resets on any WDI edge-enabling robust MCU hang detection without requiring precise pulse timing.

Reset assertion is guaranteed down to VCC = 1.0 V, with trec = 1.4 ms (typ.) after power-up recovery or MR release. The active-low open-drain RST output requires an external pull-up resistor (e.g., 10 kΩ) and supports level-shifting up to 6 V, enabling interoperability with mixed-voltage system reset buses.

Key Specifications

Pinout & Package

STM6322SWY6F is housed in a standard 5-pin SOT23-5 package (JEDEC MO-178AB), 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 with watchdog applications.

Compared with MAX6322US33D3+ and TPS3808G33DBVR, STM6322SWY6F offers the optimal balance of industrial-grade temperature range, 1.6 s watchdog margin for slower firmware cycles, and open-drain RST for flexible voltage-domain integration-without requiring additional enable logic or sacrificing brownout immunity at low VCC.

Availability

STM6322SWY6F is available at Aetrix Electronics and suitable for industrial PLC controllers, medical diagnostic devices, smart energy meters, and automotive body control modules requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for STM6322SWY6F 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 silicon solutions for automotive, industrial, and consumer markets since 1987.

STM6322SWY6F belongs to the STM6xxx supervisor family, engineered specifically for robust, low-power microprocessor reset management in harsh industrial environments where voltage monitoring accuracy, watchdog reliability, and extended temperature operation are mission-critical.

FAQ

What is the function of the WDI pin on STM6322SWY6F?

The WDI (Watchdog Input) pin is edge-sensitive: any rising or falling transition clears the internal 1.6 s watchdog timer. If WDI remains static (high or low) for ≥1.6 s, the device asserts RST. Leaving WDI unconnected disables the watchdog function, as the internal counter drives a low-high-low pulse within the timeout window.

Can STM6322SWY6F be used with a 5 V microcontroller reset input?

Yes-its open-drain RST output supports level shifting. Connect a 10 kΩ pull-up resistor from the RST pin to the 5 V supply. When asserted, the output sinks current to ground, pulling the line to logic low; when de-asserted, the pull-up raises it to 5 V, satisfying standard 5 V TTL reset input thresholds.

Does STM6322SWY6F require external components for basic operation?

No external components are required for core supervision: VCC, VSS, MR (with optional switch), and RST (with external pull-up for open-drain operation) constitute the minimal interface. The internal 52 kΩ MR pull-up eliminates need for external biasing; only the RST pull-up resistor is mandatory for functional reset signaling.

How does STM6322SWY6F ensure reset validity during deep brownout?

STM6322SWY6F guarantees RST assertion remains valid down to VCC = 1.0 V across –40 to +85 °C. This is achieved through proprietary low-voltage biasing of the internal reference and comparator, enabling reliable reset generation even as the supply collapses-critical for preventing corrupted memory writes or partial state transitions.