STMicroelectronics STM6825RWY6F

Overview

STM6825RWY6F from STMicroelectronics is a 5-pin precision voltage supervisor IC with 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 STM6825RWY6F datasheet, STM6825RWY6F pinout, STM6825RWY6F application, or STM6825RWY6F equivalent, key selection criteria include its guaranteed 1.0 V reset hold, 3 µA typical supply current, SOT23-5 footprint compatibility, and dual reset output capability (RST and RST) - critical for interfacing with bidirectional MCU reset pins and fail-safe system recovery.

Technical Context

The STM6825RWY6F integrates a precision bandgap reference and comparator to monitor VCC against a fixed 3.3 V threshold (±2.5% over –40 to +85 °C), triggering reset when undervoltage occurs. Its internal watchdog timer resets on WDI inactivity ≥1.6 s (typ.), cleared by any edge transition on WDI.

It provides two independent reset outputs: active-low push-pull RST and active-high push-pull RST, both asserted synchronously during VCC dropout, MR low, or watchdog timeout. Reset remains asserted for trec (1.4 ms typ.) after recovery, with guaranteed validity down to VCC = 1.0 V across full temperature range.

Key Specifications

Pinout & Package

The STM6825RWY6F is housed in a standard 5-pin SOT23 package (JEDEC MO-178AA), with 1.3 mm pitch, 2.9 mm × 1.6 mm body, and exposed pad not connected internally.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TRD2T and TPS3808G125DBVR, the STM6825RWY6F uniquely delivers integrated watchdog, dual-polarity reset, and MR input in a single SOT23-5 package - eliminating discrete logic or additional supervisors needed to achieve equivalent functionality.

Availability

STM6825RWY6F is available at Aetrix Electronics and suitable for industrial PLCs, smart energy meters, motor drive control boards, and medical diagnostic sensors requiring stable component supply across extended product lifecycles.

Supply support for STM6825RWY6F 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, and analog/mixed-signal ICs for industrial, automotive, and consumer markets.

The STM6xxx series was developed specifically for robust, low-power microprocessor supervision in harsh industrial environments - emphasizing guaranteed reset validity, minimal external components, and seamless integration with 3.3 V embedded systems.

FAQ

Can STM6825RWY6F be used with 5 V microcontrollers?

Yes. The STM6825RWY6F supports VCC up to 5.5 V and is specified for operation across 1.0–5.5 V. Its 3.3 V reset threshold remains accurate regardless of supply voltage, and its RST/RST outputs are fully compatible with 5 V-tolerant MCU reset inputs. Absolute maximum ratings confirm safe operation at 5 V, and internal clamping protects against transient overvoltage.

How is the watchdog function disabled?

The watchdog is disabled by leaving the WDI pin unconnected (floating) or connecting it to a tristate buffer output. In this state, the internal watchdog counter generates a self-clearing low-high-low pulse within the 1.6 s timeout window, preventing reset assertion. No external pull-up or pull-down is required, and leakage current remains below 10 µA per datasheet specifications.

What is the purpose of the RST pin?

The RST pin provides an active-high, push-pull reset output that is the logical inverse of RST. It enables direct connection to MCUs or peripherals requiring active-high reset signaling - eliminating the need for external inverters or level shifters. Both RST and RST are asserted and de-asserted simultaneously, ensuring synchronized system reset across mixed-polarity interfaces.

Does STM6825RWY6F require external capacitors?

No external capacitors are required for basic operation. The device integrates all timing elements internally, including reset delay and watchdog timeout. Only optional noise suppression (e.g., 0.1 µF capacitor from MR to GND) is recommended in high-noise environments. The SOT23-5 layout does not mandate decoupling capacitors beyond standard 100 nF placement near VCC/VSS per PCB best practices.