STMicroelectronics STM6822YAWY6F

Overview

STM6822YAWY6F from STMicroelectronics is a 5-pin precision voltage supervisor IC with integrated watchdog timer and manual reset input, designed for microprocessor power-on and fault recovery in industrial embedded systems. It monitors VCC at 3.3 V (±2.5%), asserts active-low open-drain RST for ≥1.4 ms upon undervoltage or watchdog timeout (1.6 s typ.), and operates down to VCC = 1.0 V over –40 to +85 °C.

For engineers reviewing the STM6822YAWY6F datasheet, STM6822YAWY6F pinout, STM6822YAWY6F application, or STM6822YAWY6F equivalent, key selection criteria include its open-drain RST output requiring external pull-up, guaranteed reset assertion below 3.3 V threshold, low 3 µA supply current, MR input with internal 52 kΩ pull-up, and SOT23-5 package compatibility with space-constrained PCB layouts.

Technical Context

The STM6822 implements a precision bandgap reference and comparator to detect VCC deviation from its factory-trimmed 3.3 V reset threshold (±2.5%). Its watchdog timer triggers reset if WDI remains static for ≥1.6 s, and resets on any WDI edge - enabling MCU firmware to service it via short pulses.

Reset assertion is latched and held for trec (1.4 ms typ.) after VCC recovery, MR release, or watchdog expiry. The open-drain RST output requires an external pull-up resistor (e.g., 10 kΩ) to any supply ≤6 V, supporting level-shifting across mixed-voltage domains.

Key Specifications

Pinout & Package

STM6822YAWY6F is housed in a RoHS-compliant SOT23-5 surface-mount package (2.9 × 1.6 × 1.1 mm), optimized for high-density PCB layouts and reflow-compatible assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM6822YAWY6F, MAX6322UR33+T omits manual reset and uses push-pull output - simplifying layout but limiting flexibility in field-service scenarios; TPS3808G33DBVR offers similar open-drain functionality but doubles supply current and extends reset pulse duration, affecting power-critical and timing-tight designs.

Availability

STM6822YAWY6F is available at Aetrix Electronics and suitable for industrial motor control, smart energy metering, programmable logic controllers, and industrial IoT gateways requiring stable component supply across extended product lifecycles.

Supply support for STM6822YAWY6F 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 automotive, industrial, and power management solutions with broad analog and microcontroller portfolios.

STM6xxx is ST's dedicated family of precision voltage supervisors targeting robust, low-power system reset and watchdog functionality for industrial and embedded applications - emphasizing reliability under voltage stress and minimal design overhead.

FAQ

What is the function of the WDI pin on STM6822YAWY6F?

The WDI (Watchdog Input) pin is edge-sensitive: any rising or falling transition within 1.6 seconds clears the internal watchdog timer. If WDI remains static beyond that period, RST is asserted. Leaving WDI unconnected or driving it with a tristate buffer disables the watchdog function, as the internal counter cannot toggle it reliably.

Can STM6822YAWY6F drive a 5 V microcontroller reset pin directly?

No - STM6822YAWY6F features an open-drain RST output rated for ≤6 V pull-up, but it does not source voltage. To interface with a 5 V MCU reset pin, connect a pull-up resistor (e.g., 10 kΩ) from RST to the 5 V supply. This ensures valid logic-high levels while maintaining compatibility with the device's 1.0–5.5 V VCC range.

How does the MR input behave when left unconnected?

When MR is unconnected, its internal 52 kΩ pull-up resistor biases it to VCC, holding it logic-high and disabling manual reset. No external component is needed. This state allows normal VCC- and watchdog-triggered reset operation while preventing unintended assertion - ideal for designs where physical reset buttons are optional or omitted.

Is STM6822YAWY6F suitable for automotive applications?

No - STM6822YAWY6F is specified for industrial temperature range (–40 to +85 °C) and lacks AEC-Q100 qualification. It is not rated for automotive under-hood or infotainment environments. For automotive use, ST recommends the pin-compatible AEC-Q100 qualified STM6822QYAWY6F variant, which shares identical electrical characteristics but undergoes extended reliability testing.