STMicroelectronics STM6824SWY6F

Overview

STM6824SWY6F 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 push-pull RST output, delivers 1.4 ms reset pulse width (typ.), guarantees reset assertion down to VCC = 1.0 V, and draws only 3 µA supply current (typ.) - enabling reliable power-on reset and fault recovery in low-power edge nodes.

For engineers reviewing the STM6824SWY6F datasheet, STM6824SWY6F pinout, STM6824SWY6F application, or STM6824SWY6F equivalent, key selection criteria include its guaranteed 1.0 V reset hold capability, 1.6 s watchdog timeout, SOT23-5 footprint compatibility, and dual reset output polarity support - critical for interfacing with bidirectional MCU reset pins and noise-immune manual reset implementation.

Technical Context

The STM6824SWY6F implements a precision bandgap voltage reference and comparator to monitor VCC against a fixed 3.3 V threshold (±2.5% accuracy), asserting RST when undervoltage occurs. Its internal watchdog timer triggers reset if WDI remains static for ≥1.6 s (typ.), and clears on any WDI edge transition - supporting fail-safe MCU supervision without software intervention.

It features an internal 52 kΩ pull-up on MR, enabling direct connection to momentary switches to ground without external components, and supports active-low push-pull RST output capable of sinking 20 mA while maintaining valid logic levels down to VCC = 1.0 V - ensuring deterministic reset behavior during brownout conditions.

Key Specifications

Pinout & Package

STM6824SWY6F 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 with watchdog applications.

Compared with STM6824SWY6F, MAX6324US33D3+ reduces quiescent current slightly but adds BOM cost and layout risk due to missing MR pull-up, while TPS3808G33DBVR offers configurability at the expense of higher current draw and incompatible 6-pin packaging - making STM6824SWY6F optimal for cost-sensitive, space-constrained industrial reset applications.

Availability

STM6824SWY6F is available at Aetrix Electronics and suitable for industrial PLCs, smart meters, medical infusion pumps, and automotive body control modules requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for STM6824SWY6F 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 IoT markets with focus on reliability, efficiency, and integration.

STM6xxx is ST's precision voltage supervisor product line engineered specifically for robust microprocessor reset management in harsh industrial environments - emphasizing ultra-low power, guaranteed brownout operation, and simplified manual reset implementation.

FAQ

Can STM6824SWY6F monitor voltages other than 3.3 V?

No. STM6824SWY6F is factory-trimmed for a fixed 3.3 V ±2.5% reset threshold and does not support external resistor programming or multiple voltage options. For 5 V, 2.5 V, or adjustable thresholds, ST offers STM6821 (5 V), STM6823 (2.5 V), or STM632x series with different V_TH variants - each with distinct part numbers and pin-compatible SOT23-5 packaging.

What happens to RST output when VCC drops below 1.0 V?

RST remains asserted (low) as long as VCC stays below the 3.3 V threshold, and the device guarantees valid RST signaling down to VCC = 1.0 V. Below 1.0 V, internal circuitry ceases operation and RST enters high-impedance state - but this condition occurs only after system power has fully collapsed, making continued reset assertion unnecessary for MCU recovery.

Is the watchdog function enabled by default?

Yes. The watchdog timer is active upon power-up and begins counting immediately after reset de-assertion. It can only be disabled by leaving WDI floating or connecting it to a tristated driver - with leakage current limited to 10 µA and load capacitance ≤200 pF. No configuration register or external command is required to enable it.

Does STM6824SWY6F support open-drain RST output?

No. STM6824SWY6F provides only active-low push-pull RST output (as confirmed in Table 3 and Figure 6 of the datasheet). Open-drain RST is implemented in STM6321 and STM6822 variants - which share the same SOT23-5 package but differ in pin function mapping and output structure.