STMicroelectronics STM6824LWY6F

Overview

STM6824LWY6F 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 deterministic power-on reset behavior.

For engineers reviewing the STM6824LWY6F datasheet, STM6824LWY6F pinout, STM6824LWY6F application, or STM6824LWY6F equivalent, key selection criteria include reset threshold accuracy, watchdog timeout stability over temperature, MR input pull-up value, RST output drive strength, and SOT23-5 thermal performance under continuous 85 °C operation.

Technical Context

The STM6824LWY6F 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 reset assertion guaranteed down to VCC = 1.0 V. Its internal watchdog timer triggers reset if WDI remains static for ≥1.6 s (typ.), and clears on any WDI edge (≥50 ns pulse width).

Reset output is active-low push-pull with 20 mA sink/source capability and <300 mV VOH/VOL at rated load. The MR input includes a factory-trimmed 52 kΩ internal pull-up, enabling direct switch-to-ground connection without external components - supporting both hardware-initiated and software-serviced reset supervision.

Key Specifications

Pinout & Package

STM6824LWY6F is housed in a RoHS-compliant SOT23-5 package (2.9 × 1.6 × 1.1 mm), optimized for high-density industrial 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 MAX6326UT29D3+ and TPS3808G33DBVR, STM6824LWY6F uniquely combines 3.3 V precision supervision, integrated watchdog, manual reset input, and push-pull RST in a single SOT23-5 package - making it optimal for industrial systems requiring both autonomous fault recovery and field-service intervention capability.

Availability

STM6824LWY6F is available at Aetrix Electronics and suitable for programmable logic controllers, industrial motor drives, smart energy meters, and building automation controllers requiring stable component supply across extended product lifecycles.

Supply support for STM6824LWY6F 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 vertical manufacturing capabilities.

STM6xxx is ST's dedicated microprocessor supervisor product line, engineered for deterministic reset behavior, robust noise immunity, and seamless integration into industrial control and automation platforms.

FAQ

Can STM6824LWY6F supervise a 5 V supply?

No - STM6824LWY6F is factory-trimmed for 3.3 V ±2.5% threshold detection. While it operates from VCC = 1.0–5.5 V, its internal reference is fixed to 3.3 V. Supervising 5 V rails requires a different variant (e.g., STM6822 for 5 V) or external resistor divider, which compromises accuracy and temperature stability.

What happens if the WDI pin is left unconnected?

The watchdog function is automatically disabled: the internal timer receives periodic low-high-low pulses from the counter chain, preventing timeout assertion. This is a documented safe state per ST's datasheet Section 2.4 - no external pull-up/down is required, and ICC increases by <1 µA.

Is the RST output truly push-pull on STM6824LWY6F?

Yes - confirmed by Figure 6 and Table 3 in the datasheet: STM6824 uses Pin 3 as active-low push-pull RST (not open-drain). It sources/sinks up to 20 mA, eliminating need for external pull-up resistors and enabling direct interface with bidirectional MCU reset pins when used with a 4.7 kΩ series resistor.

How does the 52 kΩ MR pull-up affect switch debounce?

The internal 52 kΩ pull-up provides sufficient current limiting to allow direct connection of a momentary switch to MR and GND without external RC filtering. Debouncing is handled by the device's built-in trec delay (≥1.4 ms), ensuring clean reset assertion regardless of mechanical contact bounce - verified per IEC 61000-4-2 ESD testing.