STMicroelectronics STM6822TWY6F

Overview

STM6822TWY6F 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 on fault or timeout, delivers 1.4 ms reset pulse width (typ.), and draws only 3 µA supply current (typ.) down to VCC = 1.0 V.

For engineers reviewing the STM6822TWY6F datasheet, STM6822TWY6F pinout, STM6822TWY6F application, or STM6822TWY6F equivalent, this device supports critical power-on sequencing, brown-out detection, and fail-safe MCU recovery in space-constrained SOT23-5 designs where low quiescent current and guaranteed reset assertion below 1.0 V are required.

Technical Context

The STM6822 implements a precision bandgap reference and comparator to monitor VCC against a fixed 3.3 V threshold (±2.5% over –40 to +85 °C), with internal timing circuitry generating a 1.4 ms reset pulse width after power-up or fault recovery. Its watchdog timer triggers reset if WDI remains static for ≥1.6 s (typ.), and clears on any WDI edge.

Reset output is active-low open-drain (RST), requiring an external pull-up resistor; MR is an active-low push-button input with internal 52 kΩ pull-up; VSS and VCC complete the 5-pin functional set. The device guarantees valid RST assertion down to VCC = 1.0 V across full industrial temperature range.

Key Specifications

Pinout & Package

STM6822TWY6F 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 reflow 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, STM6822TWY6F uniquely combines open-drain RST, integrated watchdog, MR with internal pull-up, and guaranteed 1.0 V operation-making it optimal for compact, self-recovering industrial controllers where reset bus sharing and brown-out resilience are mandatory.

Availability

STM6822TWY6F is available at Aetrix Electronics and suitable for industrial automation, smart metering, medical handhelds, and automotive body electronics requiring stable component supply across extended product lifecycles.

Supply support for STM6822TWY6F 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 embedded markets with emphasis on reliability, longevity, and ecological responsibility.

STM6xxx is ST's precision voltage supervisor product line targeting microprocessor reset assurance in harsh environments, featuring integrated watchdog, manual reset, and ultra-low-power operation for long-lifecycle industrial deployments.

FAQ

What is the function of Pin 1 (WDI) on STM6822TWY6F?

Pin 1 is the Watchdog Input (WDI), an edge-sensitive control signal that resets the internal watchdog timer on any rising or falling transition. If WDI remains static for ≥1.6 s (typ.), the device asserts RST. Leaving WDI unconnected or driving it with a tristate buffer disables the watchdog function entirely, as confirmed in the datasheet Section 1.1.4 and Figure 26.

Can STM6822TWY6F drive a reset line directly without external components?

No-its RST output is active-low open-drain and requires an external pull-up resistor to define the high logic level. A 10 kΩ resistor to 3.3 V is recommended per Figure 11 and Section 2.2. Unlike push-pull variants (e.g., STM6823), STM6822 cannot source current and will not assert a valid high state without this component.

Does STM6822TWY6F support 2.5 V or 5 V supply rails?

Yes-STM6822TWY6F operates across VCC = 1.0 V to 5.5 V (Table 4, Absolute Maximum Ratings), but its internal voltage detector is factory-trimmed to 3.3 V ±2.5%. It monitors only 3.3 V rails; for 2.5 V or 5 V supervision, ST offers STM6821 (5 V) and STM6824 (2.5 V) in the same family, as shown in Table 1.

How does STM6822TWY6F behave during power-down below 1.0 V?

The device guarantees RST assertion remains valid down to VCC = 1.0 V across –40 to +85 °C (Section 2.1). Below 1.0 V, internal circuitry ceases operation and RST releases; however, due to the open-drain structure, the external pull-up holds the line high-preventing undefined states. This behavior is explicitly documented in Section 2.5.2 and Figure 11.