Diodes Incorporated APX812-44UG-7

Overview

APX812-44UG-7 from Diodes Incorporated is a 4-pin microprocessor supervisor IC with manual reset input and active-high push-pull RESET output, designed for precise power supply monitoring in 4.38 V systems. It features a fixed 200 ms reset timeout, operates across –40°C to +85°C, and delivers ±1.5% reset threshold accuracy at 25°C. Used in embedded controllers and portable equipment to prevent erroneous code execution during brownout or power-up.

For engineers reviewing the APX812-44UG-7 datasheet, APX812-44UG-7 pinout, APX812-44UG-7 application, or APX812-44UG-7 equivalent, key selection criteria include reset threshold voltage (4.38 V), active-high output logic, manual reset compatibility, SOT143 package footprint, and industrial temperature range compliance.

Technical Context

The APX812-44UG-7 implements a precision bandgap-based voltage reference and comparator to monitor V_CC, asserting RESET high when V_CC falls below 4.38 V (±1.5% at 25°C) or when MR is pulled low. Its internal delay circuit ensures minimum 240 ms reset assertion after V_CC recovery.

It uses a push-pull output stage capable of sourcing 800 µA at V_CC – 1.5 V and sinking 3.2 mA at 0.4 V, enabling direct interface with CMOS inputs without external pull-up/pull-down resistors under normal operation. The device remains functional down to V_CC = 1.1 V and supports manual reset pulse widths as short as 100 ns.

Key Specifications

Pinout & Package

APX812-44UG-7 is housed in a RoHS-compliant, lead-free SOT143 (TO-253-4) surface-mount package measuring 2.9 mm × 1.5 mm × 1.1 mm, with gull-wing leads optimized for automated reflow assembly and thermal dissipation (θ_JA = 240°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809SEUR+T and TPS3808G33DBVR, the APX812-44UG-7 uniquely combines 4.38 V precision threshold, integrated manual reset, active-high push-pull output, and SOT143 footprint-enabling single-component reset supervision without external timing components or compromise on reset polarity.

Availability

APX812-44UG-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 support, and RoHS-compliant packaging.

Supply support for APX812-44UG-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 and automotive markets.

The APX811/812 series was developed specifically for cost-sensitive, space-constrained microprocessor reset supervision in 2.5 V to 5.0 V systems, emphasizing precision threshold accuracy, zero-external-component operation, and industrial-grade environmental robustness.

FAQ

What is the exact reset threshold voltage for APX812-44UG-7?

The APX812-44UG-7 has a nominal reset threshold of 4.38 V, with guaranteed tolerance of ±1.5% at 25°C and full specification across –40°C to +85°C. Measured values fall within 4.31 V to 4.45 V per datasheet Electrical Characteristics table, making it suitable for systems powered from tightly regulated 4.38 V rails.

Does APX812-44UG-7 require an external capacitor for reset timing?

No. The APX812-44UG-7 integrates a factory-trimmed 200 ms reset timeout circuit with no external components required. This eliminates timing capacitor variability, PCB area, and potential failure modes associated with discrete timing elements-unlike many competing supervisors that rely on RC networks.

Can APX812-44UG-7 drive a standard CMOS microcontroller reset input directly?

Yes. Its active-high push-pull RESET output sources up to 800 µA at V_CC – 1.5 V and sinks up to 3.2 mA at 0.4 V, meeting standard CMOS input drive requirements. No external pull-up resistor is needed, simplifying schematic design and reducing parasitic leakage paths.

How does the manual reset (MR) pin interact with the power-on reset function?

The MR pin is asynchronous and overrides the power-on reset timer: pulling MR low forces RESET high immediately, regardless of V_CC level. When MR returns high, RESET remains high for the full 200 ms timeout period-even if V_CC is already above threshold-ensuring clean, debounced reset initiation for diagnostics or recovery sequences.