Diodes Incorporated APX809S00-40SR-7

Overview

APX809S00-40SR-7 from Diodes Incorporated is a micro-power voltage detector IC designed for µP supervisory functions in embedded digital systems. It provides active-low reset assertion when VCC drops below 4.00 V (typ.), maintains reset for ≥240 ms after VCC recovery, operates down to 1.0 V supply, draws only 7 µA typical supply current, and features push-pull output in SOT23-3 (SR) package-used in battery-powered controllers and portable instrumentation.

For engineers reviewing the APX809S00-40SR-7 datasheet, APX809S00-40SR-7 pinout, APX809S00-40SR-7 application, or APX809S00-40SR-7 equivalent, key selection criteria include reset threshold accuracy (±0.06 V), guaranteed reset validity at VCC = 1 V, 240 ms minimum timeout, push-pull drive capability (1.2 mA sink), and SOT23-3 footprint compatibility with space-constrained PCB layouts.

Technical Context

The APX809S00-40SR-7 integrates a precision bandgap reference, comparator, and power-on reset timer to monitor VCC against a fixed 4.00 V threshold. Its internal circuitry ignores fast transients and ensures monotonic reset deassertion only after VCC exceeds VTH + 1.5% for ≥240 ms.

It uses no external components, delivers rail-to-rail output logic states over VCC = 1.0–5.5 V, and guarantees VOL ≤ 0.3 V at 1.2 mA sink load-enabling direct interface with 3.3 V and 5 V µP reset inputs without pull-up resistors.

Key Specifications

Pinout & Package

APX809S00-40SR-7 is housed in a RoHS-compliant, halogen-free SOT23-3 (SR) package with 1.3 mm × 2.4 mm footprint and 0.95 mm height-optimized for high-density PCBs in handheld and IoT edge nodes.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TRD2T and TPS3808G33DBVR, APX809S00-40SR-7 uniquely combines precise 4.00 V detection, 240 ms guaranteed timeout, push-pull drive, and 7 µA consumption-making it optimal for space- and timing-constrained 5 V µP systems where BOM simplification and deterministic reset behavior are mandatory.

Availability

APX809S00-40SR-7 is available at Aetrix Electronics and suitable for industrial PLC controllers, portable medical monitors, and smart energy meters requiring stable component supply across extended product lifecycles.

Supply support for APX809S00-40SR-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 consumer markets.

The APX809S/810S series was developed to replace discrete reset circuits in cost-sensitive, space-constrained µP systems-delivering precision voltage monitoring, low power, and robust transient immunity in minimal SOT23-3 packaging.

FAQ

What is the exact reset threshold voltage and its tolerance for APX809S00-40SR-7?

The APX809S00-40SR-7 has a nominal reset threshold of 4.00 V at +25°C, with a guaranteed range of 3.94 V to 4.05 V across temperature and process variation. This 4.00 V specification targets 5 V supply rails, providing a 2% margin before brownout-induced µP malfunction.

Does APX809S00-40SR-7 require an external capacitor for reset timing?

No. The 240 ms minimum reset timeout is fully internal and does not rely on external capacitors. The device uses an on-chip oscillator and counter to guarantee timing-eliminating capacitor aging, temperature drift, and placement sensitivity found in RC-based solutions.

Can APX809S00-40SR-7 operate with a 3.3 V supply rail?

No. Its 4.00 V threshold is designed for 5 V systems. When powered from 3.3 V, VCC remains below VTH, causing continuous RESET assertion. For 3.3 V rails, use APX809S-31SR-7 (3.08 V threshold) or APX809S-33SR-7 (3.30 V threshold), both in identical SOT23-3 packaging.

Is the RESET output truly push-pull, and what is its drive strength?

Yes. The RESET pin actively drives low (≤0.3 V at 1.2 mA sink) and actively drives high (≥0.8×VCC at 500 µA source). This eliminates external pull-up resistors, reduces standby current, and ensures fast, rail-aligned transitions compatible with modern µP reset inputs.