STMicroelectronics STM6822RWY6F

Overview

STM6822RWY6F 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 3.3 V power supplies, provides active-low open-drain RST output, delivers 1.4 ms reset pulse width (typ.), guarantees reset assertion down to VCC = 1.0 V, and consumes only 3 µA typical supply current.

For engineers reviewing the STM6822RWY6F datasheet, STM6822RWY6F pinout, STM6822RWY6F application, or STM6822RWY6F equivalent, this device serves as a low-power, temperature-stable reset supervisor for MCU-based control units where reliable power-on sequencing, brown-out detection, and software fault recovery are critical.

Technical Context

The STM6822RWY6F implements a precision bandgap reference and comparator to monitor VCC against a fixed 3.3 V threshold (±2.5% over –40 to +85 °C). Its watchdog timer triggers reset if WDI remains static for ≥1.6 s (typ.), and its MR input features an internal 52 kΩ pull-up for direct push-button interfacing without external components.

Reset assertion is guaranteed valid down to VCC = 1.0 V, and the open-drain RST output requires an external pull-up resistor (e.g., 10 kΩ) to interface with logic levels up to 6 V. The device operates across full industrial temperature range (–40 to +85 °C) and meets RoHS compliance.

Key Specifications

Pinout & Package

The STM6822RWY6F is housed in a standard 5-pin SOT23 package (JEDEC MO-178AB), with 1.3 mm × 2.9 mm body size, 0.95 mm height, and 0.95 mm pitch. Pin 1 is marked with a dot; pin numbering follows counter-clockwise order from the mark.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6322US33D3+ and TPS3808G33DBVR, the STM6822RWY6F offers fixed 1.6 s watchdog timing with zero external components, lowest supply current (3 µA), and open-drain RST for flexible voltage translation-making it optimal for cost-sensitive, space-constrained industrial designs needing proven reliability and minimal BOM count.

Availability

STM6822RWY6F is available at Aetrix Electronics and suitable for industrial PLC controllers, smart energy meters, motor drive control boards, and building automation nodes requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for STM6822RWY6F 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 innovative silicon solutions for automotive, industrial, and power management applications.

The STM6xxx series is ST's dedicated family of micropower supervisors targeting industrial-grade microprocessor reset assurance, combining precision voltage monitoring, manual reset, and watchdog functionality in minimal-footprint packages.

FAQ

What is the function of the WDI pin on STM6822RWY6F?

The WDI (Watchdog Input) pin is an asynchronous edge-sensitive input that resets the internal watchdog timer on each rising or falling edge. If WDI remains static for ≥1.6 s (typ.), the device asserts RST. Leaving WDI unconnected disables the watchdog function, as the internal counter drives it with periodic pulses.

Can STM6822RWY6F monitor voltages other than 3.3 V?

No - STM6822RWY6F is factory-trimmed for a fixed 3.3 V reset threshold (±2.5%). It does not support adjustable or user-selectable thresholds. For 2.5 V, 3.0 V, or 5.0 V monitoring, ST offers other members of the STM682x family (e.g., STM6821 for 5 V, STM6823 for 3.0 V).

Why does STM6822RWY6F use an open-drain RST output instead of push-pull?

The open-drain RST output enables level translation: it can interface with logic systems operating at voltages up to 6 V using an external pull-up resistor. This avoids bus contention in multi-supply systems and simplifies integration with MCUs having bidirectional reset pins when combined with a series resistor.

How does the MR input behave when left unconnected?

When MR is left unconnected, its internal 52 kΩ pull-up resistor holds it at logic high, disabling manual reset. The input is TTL/CMOS-compatible and may be driven directly by switches or logic outputs. No external pull-up is required, and no debounce circuitry is needed for momentary switch use.