Diodes Incorporated APX809S05-44SR-7

Overview

APX809S05-44SR-7 from Diodes Incorporated is a micro-power voltage detector IC designed for µP supervisory functions in +5V digital systems. It provides active-low reset assertion when VCC drops below 4.38V (typ), maintains reset for ≥240ms after recovery, and operates with 7µA supply current. Its push-pull output drives logic-level loads directly without external pull-up resistors, enabling reliable power-on reset in battery-powered controllers.

For engineers reviewing the APX809S05-44SR-7 datasheet, APX809S05-44SR-7 pinout, APX809S05-44SR-7 application, or APX809S05-44SR-7 equivalent, key selection criteria include reset threshold accuracy (±0.06V over temperature), guaranteed operation down to VCC = 1V, 240ms timeout period, SOT23-3 package footprint, and compatibility with 5V microcontroller power rails.

Technical Context

The APX809S05-44SR-7 integrates a precision bandgap reference and comparator to monitor VCC against a fixed 4.38V threshold. Its internal timing circuit generates a minimum 240ms reset pulse width after VCC exceeds the threshold, independent of external components. The device ignores fast transients on VCC via built-in noise immunity.

It features a push-pull output stage capable of sinking 1.2mA at 0.3V (max) and sourcing 500µA while maintaining VOH ≥ 0.8×VCC - eliminating need for external pull-ups. Operation is fully specified from −40°C to +125°C ambient, with reset threshold drift limited to 30ppm/°C.

Key Specifications

Pinout & Package

APX809S05-44SR-7 is housed in a RoHS-compliant, halogen-free SOT23-3 package (JEDEC TO-236AB), measuring 2.9mm × 1.3mm × 1.0mm with 0.95mm lead pitch. The package supports reflow soldering per J-STD-020 and is rated for 232°C/W junction-to-ambient thermal resistance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809SEUR+T and TPS3808G33DBVR, APX809S05-44SR-7 delivers optimal fit for legacy 5V µP designs needing fixed 4.38V detection, guaranteed 240ms hold time, and minimal quiescent current - all in a cost-optimized SOT23-3 footprint without configuration overhead.

Availability

APX809S05-44SR-7 is available at Aetrix Electronics and suitable for industrial PLC I/O modules, battery-powered data loggers, medical point-of-care monitors, and smart energy meters requiring stable component supply across extended product lifecycles.

Supply support for APX809S05-44SR-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, serving industrial, computing, communications, and consumer markets with high-reliability, cost-optimized components.

The APX809S/810S series targets microprocessor supervisory functions in space-constrained, low-power applications - delivering precision voltage monitoring, robust reset timing, and simplified design-in through integrated push-pull outputs.

FAQ

What is the exact reset threshold voltage for APX809S05-44SR-7?

The APX809S05-44SR-7 has a nominal reset threshold of 4.38V at +25°C, with a guaranteed range of 4.32V to 4.44V across temperature and process variation. This value is laser-trimmed during production and remains stable within ±0.06V over the full −40°C to +125°C operating range.

Can APX809S05-44SR-7 operate with a 3.3V supply?

No - APX809S05-44SR-7 is specifically trimmed for 5V system supervision and requires VCC ≥ 1.0V to assert valid reset. While it will function electrically down to 1V, its 4.38V threshold makes it unsuitable for reliable monitoring of 3.3V rails; use APX809S05-33SR-7 instead for that voltage level.

Does this device require an external capacitor for reset timing?

No. The 240ms minimum reset timeout is generated entirely by internal circuitry. No external capacitor or resistor is needed - simplifying layout, reducing bill-of-materials cost, and eliminating timing drift due to component aging or temperature effects.

Is APX809S05-44SR-7 compatible with lead-free reflow profiles?

Yes. The device uses a fully RoHS-compliant, lead-free, halogen-free molding compound and meets JEDEC J-STD-020D.3 moisture sensitivity level 1 (MSL-1), supporting standard Pb-free reflow profiles up to 260°C peak temperature without preconditioning.