Diodes Incorporated APX811-31UG-7

Overview

APX811-31UG-7 from Diodes Incorporated is a 4-pin microprocessor supervisor IC with manual reset input, designed for precise power supply monitoring in embedded systems. It features a 3.08 V reset threshold, active-low push-pull RESET output, 200 ms power-on reset timeout, and operates across –40°C to +85°C in SOT143 package. Used in microcontroller-based equipment requiring reliable brownout protection.

For engineers reviewing the APX811-31UG-7 datasheet, APX811-31UG-7 pinout, APX811-31UG-7 application, or APX811-31UG-7 equivalent, key selection criteria include reset threshold accuracy (±1.5% over temperature), MR input compatibility with TTL/CMOS logic, guaranteed RESET assertion down to VCC = 1.0 V, and industrial-grade thermal performance in space-constrained designs.

Technical Context

The APX811-31UG-7 integrates a precision voltage reference, comparator, and 200 ms delay timer to generate a clean, glitch-free active-low reset signal. Its internal circuitry ensures RESET remains asserted for ≥240 ms after VCC recovers above 3.08 V, with full specification across –40°C to +85°C ambient.

It supports dual reset initiation: automatic detection of VCC drop below 3.08 V and asynchronous assertion via low-active MR input. The push-pull output drives CMOS/TTL loads directly without external pull-up, sinking up to 1.2 mA at VOL ≤ 0.3 V while maintaining rail-to-rail logic levels.

Key Specifications

Pinout & Package

SOT143 (4-pin, 2.9 mm × 1.5 mm, 1.1 mm height) - green molding compound, lead-free/RoHS-compliant, thermal resistance θJA = 240°C/W on standard FR-4 PCB.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809SEUR+T and TPS3808G30DBVR, the APX811-31UG-7 uniquely combines MR support, push-pull output, and ultra-low ICC in SOT143-making it optimal for cost-sensitive, space-limited industrial and portable designs where deterministic reset timing and manual override are mandatory.

Availability

APX811-31UG-7 is available at Aetrix Electronics and suitable for industrial PLC controllers, portable medical monitors, and automotive body control modules requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for APX811-31UG-7 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability power management, signal integrity, and protection solutions for industrial, computing, and automotive markets.

The APX811/812 series belongs to Diodes' microprocessor supervisor product line, engineered specifically for deterministic power-on reset generation and brownout protection in resource-constrained embedded systems operating across extended temperature ranges.

FAQ

What is the minimum VCC required for APX811-31UG-7 to assert a valid RESET signal?

The APX811-31UG-7 guarantees RESET assertion down to VCC = 1.0 V. Below this, the output enters high-impedance state. For applications requiring RESET validity at VCC < 1.0 V, a 100 kΩ pull-down resistor on the RESET pin is recommended to prevent floating logic states during deep brownout or power-down sequences.

How does the MR input interact with the automatic reset function?

The MR input is asynchronous and overrides automatic reset behavior: pulling MR low forces immediate active-low RESET assertion regardless of VCC level. When MR returns high, RESET remains low for the full 200 ms timeout period if VCC is above 3.08 V; otherwise, RESET stays low until VCC rises above threshold and the timer completes.

Can APX811-31UG-7 supervise a 2.5 V supply rail?

No - the APX811-31UG-7 has a fixed 3.08 V reset threshold optimized for 3.0 V and 3.3 V systems. For 2.5 V supervision, Diodes offers APX811-23UG-7 (2.25 V threshold) or APX811-26UG-7 (2.63 V threshold), both in identical SOT143 package and pinout.

Is the 200 ms reset timeout adjustable?

No - the 200 ms delay is internally fixed and not user-adjustable. It is trimmed during wafer test to meet 140–280 ms min–max specification. For programmable timeout, consider Diodes' APX809 series with external capacitor option or TPS3808 family with selectable delay configurations.