STMicroelectronics STM1831L24WY6F

Overview

STM1831L24WY6F from STMicroelectronics is a precision voltage detector IC with dedicated sense input (VSEN), factory-trimmed 2.4 V detection threshold (±2% accuracy), open-drain active-low RST output, and external capacitor-programmable delay. It operates from 1.6 V to 6.0 V supply, draws only 0.8 µA typical supply current, and functions across –40 °C to +85 °C - used in microprocessor reset circuits where low-power, accurate brownout monitoring is critical.

For engineers reviewing the STM1831L24WY6F datasheet, STM1831L24WY6F pinout, STM1831L24WY6F application, or STM1831L24WY6F equivalent, key selection factors include its separate VSEN input enabling zero-voltage monitoring, programmable release delay via CD pin, ±2% threshold accuracy over temperature, and SOT23-5 package compatibility with space-constrained embedded power management designs.

Technical Context

The STM1831 implements a precision bandgap-based voltage reference and comparator architecture with internal hysteresis (0.02–0.08 × VDET) to prevent oscillation during threshold crossing. Its VSEN input remains functional down to 0 V, decoupling internal sensing circuitry from VCC when supply drops near zero - minimizing sense current (≤500 nA at VCC > 1.6 V).

Delay timing is generated by an internal 2.0 MΩ (typ.) pull-down resistor on the CD pin charging an external capacitor; tCD is calculated as ≈1.39×10⁶ × CD (seconds). The open-drain RST output supports wired-OR configurations and pull-up to voltages up to 7.0 V independent of VCC.

Key Specifications

Pinout & Package

STM1831L24WY6F is housed in a RoHS-compliant, lead-free SOT23-5 package (ECOPACK®), measuring 2.90 mm × 2.80 mm × 1.45 mm with 0.95 mm pin pitch. The package supports reflow soldering (peak 260 °C, ≤30 s above 255 °C) and provides thermal performance suitable for high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV803EB24DBZR and MAX809SEUR+T, STM1831L24WY6F uniquely supports independent VSEN monitoring and capacitor-programmable delay - essential for battery-backed memory, charge termination, and transient-immune power failure detection where flexibility and precision outweigh minimal footprint savings.

Availability

STM1831L24WY6F is available at Aetrix Electronics and suitable for microprocessor reset circuitry, charge voltage monitors, memory battery backup switch circuits, and power failure detection circuits requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for STM1831L24WY6F 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, designing and manufacturing analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

STM1831 belongs to ST's precision voltage supervisor product line, engineered specifically for ultra-low-power, high-accuracy reset and monitoring functions in space- and energy-constrained embedded systems.

FAQ

What is the function of the CD pin on STM1831L24WY6F?

The CD pin connects to an external capacitor to program the release delay time (tREL + tCD) after VSEN rises above the 2.4 V threshold. An internal 2.0 MΩ (typ.) resistor charges the capacitor; delay scales linearly with capacitance (≈1.39 s/F). Leaving CD open disables delay (tCD = 0 ms), making it configurable per application without redesign.

Can STM1831L24WY6F monitor a voltage lower than its VCC supply?

Yes. The dedicated VSEN pin operates independently of VCC and functions down to 0 V, even when VCC is near 0 V. Internal circuitry disconnects the voltage divider from VSEN under low-VCC conditions to limit sense current to ≤500 nA - enabling reliable monitoring of battery or backup rails that may collapse before the main supply.

What is the maximum allowable voltage on the RST output pin?

The RST pin is an N-channel open-drain output rated for up to 7.0 V, allowing pull-up to any voltage rail ≤7.0 V - including 5 V or 3.3 V logic supplies independent of VCC. This supports mixed-voltage system interfacing and wired-OR reset buses without level-shifting components.

How does temperature affect the 2.4 V detection threshold?

The detect voltage drifts ±100 ppm/°C relative to VDET, resulting in ±240 µV/°C change. Over –40 °C to +85 °C, total variation is ±30 mV (±1.25%) - well within the ±2% initial accuracy spec. Hysteresis (0.05 × VDET) also tracks temperature, maintaining noise immunity across the full range.