STMicroelectronics STM6825TWY6F

Overview

STM6825TWY6F 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, guarantees reset assertion down to VCC = 1.0 V, and features 1.6 s watchdog timeout - used in power-up sequencing and fault recovery for MCU-based controllers.

For engineers reviewing the STM6825TWY6F datasheet, STM6825TWY6F pinout, STM6825TWY6F application, or STM6825TWY6F equivalent, key selection criteria include guaranteed reset validity below 1.0 V VCC, SOT23-5 footprint compatibility, MR input with internal 52 kΩ pull-up, and absence of watchdog function (as confirmed in device summary Table 1).

Technical Context

The STM6825TWY6F implements a precision bandgap reference and comparator to detect VCC undervoltage conditions relative to a fixed 3.3 V threshold (±2.5%). Its reset logic asserts RST low during VCC dropout, MR low assertion, or power-up delay (trec), with reset deassertion delayed by 1.4 ms after VCC recovery.

Unlike STM6821–6824 variants, STM6825 excludes watchdog functionality per Table 1 and Figure 2 logic diagram. It provides only active-low push-pull RST and MR inputs - no WDI pin operation - simplifying integration where watchdog supervision is handled externally or omitted.

Key Specifications

Pinout & Package

SOT23-5 package: compact 2.9 mm × 1.6 mm surface-mount footprint with standard lead pitch (0.95 mm), optimized for space-constrained PCB layouts in industrial control and IoT edge nodes.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM6823TWY6F, STM6825TWY6F removes watchdog dependency for simpler firmware integration; versus TPS3808G33DBVR, it trades lower ICC for essential MR support and tighter 1.4 ms reset timing - critical for real-time industrial control loops.

Availability

STM6825TWY6F is available at Aetrix Electronics and suitable for industrial PLCs, smart energy meters, factory HMIs, and medical sensor nodes requiring stable component supply across extended product lifecycles.

Supply support for STM6825TWY6F 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 specializing in automotive, industrial, and power management solutions, with broad analog and mixed-signal portfolio.

The STM6xxx series targets cost-sensitive, space-constrained microprocessor supervisory applications - delivering precision reset control, low power, and industrial temperature reliability in minimal SOT23-5 packaging.

FAQ

Does STM6825TWY6F include a watchdog timer?

No. Per Table 1 in the official datasheet (DocID11110 Rev 14), STM6825 is explicitly excluded from the watchdog-enabled devices (STM6321/6821–6824). The WDI pin is present but non-functional; leaving it unconnected disables watchdog behavior entirely.

What is the exact reset threshold voltage and tolerance for STM6825TWY6F?

The STM6825TWY6F has a nominal VCC reset threshold of 3.3 V with ±2.5% tolerance over –40 °C to +85 °C, as specified in Section 5 (DC and AC parameters) and confirmed in Table 6 of the datasheet. This corresponds to 3.2175 V (min) to 3.3825 V (max) at 25 °C.

Can STM6825TWY6F drive a reset line directly without external components?

Yes. Its RST pin is an active-low push-pull output capable of sinking and sourcing current per Figure 21–22. It drives MCU reset lines directly without pull-up resistors, unlike open-drain variants (e.g., STM6322), and meets standard TTL/CMOS logic level requirements.

Is the MR pin of STM6825TWY6F compatible with mechanical push buttons?

Yes. The MR pin features an internal 52 kΩ pull-up resistor (Section 1.1.3), allowing direct connection of a normally-open momentary switch between MR and GND. No external resistor or debounce circuitry is required for typical industrial button interfaces.