STMicroelectronics STM6825LWY6F

Overview

STM6825LWY6F 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 on power-up or fault, guarantees reset assertion down to VCC = 1.0 V, and features 1.6 s watchdog timeout with WDI edge-triggered clearing.

For engineers reviewing the STM6825LWY6F datasheet, STM6825LWY6F pinout, STM6825LWY6F application, or STM6825LWY6F equivalent, key selection criteria include guaranteed reset validity below 1.0 V VCC, low 3 µA supply current, SOT23-5 footprint compatibility, and dual reset outputs (RST/RST) supporting bidirectional MCU reset I/O interfacing via series resistor.

Technical Context

The STM6825LWY6F implements a precision bandgap reference and comparator to detect VCC undervoltage conditions relative to its fixed 3.3 V threshold. Its reset logic combines power-on reset timing (trec), MR-triggered reset persistence, and watchdog timeout detection - all synchronized to internal state machine transitions that ensure deterministic RST assertion/deassertion timing.

It supports three independent reset sources: VCC dropout, MR low pulse, and WDI timeout (1.6 s typ.), with RST output held low for ≥1.4 ms after any trigger event. The active-high RST output is strictly complementary to RST, enabling direct interface to MCUs requiring either polarity without external inversion.

Key Specifications

Pinout & Package

STM6825LWY6F is housed in a RoHS-compliant SOT23-5 package (3.0 × 1.7 × 1.3 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 applications.

Compared with STM6825LWY6F, STM6823LWY6F sacrifices push-pull drive strength and dual-polarity outputs for open-drain configurability, while MAX6326UT46D3+ omits watchdog and manual reset entirely - making STM6825LWY6F uniquely suited for compact, feature-complete 3.3 V microprocessor supervision.

Availability

STM6825LWY6F is available at Aetrix Electronics and suitable for industrial automation, smart metering, medical handhelds, and automotive body electronics requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for STM6825LWY6F 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 microcontrollers, power management, analog ICs, and sensors for industrial, automotive, and consumer markets.

The STM6xxx family was engineered specifically for robust, low-power microprocessor supervision in space-constrained industrial and automotive applications - emphasizing guaranteed reset behavior under brownout, minimal external components, and seamless MCU integration.

FAQ

Can STM6825LWY6F be used with a 5 V microcontroller supply?

Yes - STM6825LWY6F operates from 1.0 V to 5.5 V and monitors VCC at its fixed 3.3 V threshold. When powered from a 5 V rail, it still asserts reset if that rail drops below 3.22 V (3.3 V −2.5%). Its RST/RST outputs are push-pull and compatible with 5 V logic levels, provided VCC ≤ 5.5 V and output load stays within 20 mA sink/source limits.

How is the watchdog timer disabled on STM6825LWY6F?

The watchdog is disabled by leaving the WDI pin unconnected (floating) or connecting it to a tristated output. In this state, internal leakage (<10 µA) and capacitance (<200 pF) keep the timer inactive. No configuration register or external signal is needed - it is a hardware-level disable mode inherent to the pin's electrical behavior.

What is the purpose of the complementary RST and RST outputs?

RST (active-low) and RST (active-high) are strictly complementary push-pull outputs driven from the same internal reset state. This allows simultaneous connection to two different subsystems - e.g., RST to the MCU and RST to an FPGA or peripheral ASIC - without external inverters, reducing component count and board area in multi-chip designs.

Does STM6825LWY6F require external components for basic operation?

No - STM6825LWY6F requires only VCC and VSS connections for core supervision. The MR input has an internal 52 kΩ pull-up, enabling direct switch-to-ground connection. RST is push-pull, so no pull-up resistor is needed. Only optional components include a 0.1 µF MR bypass capacitor for noise immunity or a 4.7 kΩ series resistor when interfacing with bidirectional MCU reset pins.