STMicroelectronics STM6823SWY6F

Overview

STM6823SWY6F 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 push-pull RST for ≥1.4 ms, features 1.6 s watchdog timeout, and guarantees reset assertion down to VCC = 1.0 V - used in programmable logic controllers and motor control drives requiring reliable power-on and fault recovery.

For engineers reviewing the STM6823SWY6F datasheet, STM6823SWY6F pinout, STM6823SWY6F application, or STM6823SWY6F equivalent, key selection criteria include its 3.3 V threshold accuracy, dual reset capability (RST + RST), SOT23-5 package compatibility, low 3 µA supply current, and guaranteed operation over –40 to +85 °C.

Technical Context

The STM6823SWY6F implements a precision bandgap reference and comparator to monitor VCC against a fixed 3.3 V threshold. Its reset logic combines power-on reset timing (trec = 1.4 ms typ.), MR-triggered reset with internal 52 kΩ pull-up, and watchdog timeout detection on WDI edge transitions or static high/low states exceeding 1.6 s.

It provides two independent reset outputs: active-low push-pull RST (Pin 3) and active-high push-pull RST (Pin 5), enabling direct interface with MCUs requiring either polarity. The device operates across 1.0–5.5 V VCC and maintains valid reset assertion even as VCC drops to 1.0 V, ensuring deterministic behavior during brownout conditions.

Key Specifications

Pinout & Package

STM6823SWY6F is housed in a RoHS-compliant SOT23-5 surface-mount package (3.0 × 1.7 × 1.3 mm), optimized for space-constrained industrial PCBs and compatible with standard reflow profiles (peak 260 °C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326UT46D3+ and TPS3808G33DBVR, STM6823SWY6F uniquely delivers matched 3.3 V threshold, dual RST/RST outputs, integrated MR, and watchdog in SOT23-5 - making it optimal for space-constrained industrial MCUs needing full reset flexibility without added components.

Availability

STM6823SWY6F is available at Aetrix Electronics and suitable for programmable logic controllers, industrial motor drives, smart energy meters, and factory automation remote I/O nodes requiring stable component supply across extended product lifecycles.

Supply support for STM6823SWY6F 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 strong emphasis on reliability and longevity.

STM6xxx is ST's dedicated microprocessor supervisory IC family targeting industrial and embedded applications where deterministic reset behavior, wide temperature operation, and watchdog safety are critical design requirements.

FAQ

Can STM6823SWY6F monitor a 2.5 V supply?

No. STM6823SWY6F is factory-trimmed for 3.3 V ±2.5% threshold detection. It does not support 2.5 V, 5 V, or adjustable thresholds. For 2.5 V supervision, ST offers STM6822SWY6F (same package, 2.5 V threshold, open-drain RST only) or STM6321MWY6F (2.5 V, open-drain RST).

Is the watchdog function enabled by default?

Yes. The watchdog timer is active upon power-up and requires periodic WDI toggling (rising or falling edge) within 1.6 s to prevent reset assertion. It can be disabled by leaving WDI unconnected or driving it with a tristate buffer - confirmed by ST's datasheet Section 2.4 and Figure 26 timing diagram.

What is the maximum capacitive load on the RST output?

The RST (Pin 3) push-pull output is rated for ≤20 mA sink/source and exhibits <10 ns rise/fall times into ≤50 pF load (per Table 6 AC characteristics and Figure 21/22). For loads >50 pF, add a series resistor (e.g., 33 Ω) to damp ringing without affecting reset timing compliance.

Does STM6823SWY6F support reset extension via external capacitor?

No. Reset pulse width (1.4 ms typ.) is internally fixed and not adjustable. Unlike some supervisors with CEXT pins, STM6823SWY6F uses a monolithic timer; no external components modify trec. This ensures consistent, temperature-stable reset duration across –40 to +85 °C.