Diodes Incorporated APX809S-29SR-7

Overview

APX809S-29SR-7 from Diodes Incorporated is a micro-power voltage detector IC designed for µP supervisory functions in 2.93V nominal supply monitoring applications. It features an active-low push-pull RESET output, 240ms minimum reset timeout, 7µA typical supply current, and guaranteed operation down to VCC = 1.0V - enabling reliable power-on reset in portable and battery-powered systems.

For engineers reviewing the APX809S-29SR-7 datasheet, APX809S-29SR-7 pinout, APX809S-29SR-7 application, or APX809S-29SR-7 equivalent, key selection criteria include reset threshold accuracy (±0.04V), temperature coefficient (30ppm/°C), low-voltage validity (1.0V), push-pull drive capability (1.2mA sink), and SOT23-SR package compatibility with space-constrained PCB layouts.

Technical Context

The APX809S-29SR-7 integrates a precision bandgap reference and comparator to monitor VCC against a fixed 2.93V threshold (typical), with hysteresis omitted per design. Its internal timing circuit ensures ≥240ms RESET assertion after VCC recovers above threshold, independent of external components.

It operates across –40°C to +125°C ambient, with supply current stable at ≤16µA (max) over temperature and reset output logic states fully defined down to VCC = 1.0V - supporting brown-out detection in deep-sleep or ultra-low-power modes.

Key Specifications

Pinout & Package

APX809S-29SR-7 is housed in a RoHS-compliant, halogen-free SOT23-3 (SR) package with gull-wing leads, 1.3mm pitch, and 2.9mm × 1.3mm footprint - optimized for automated placement and reflow in high-density consumer and industrial PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TRD2T and TPS3808G33DBVR, APX809S-29SR-7 delivers exact 2.93V detection, fixed 240ms hold, and zero-component push-pull drive - making it optimal for cost-sensitive, space-constrained 2.9V µP supervision where timing and simplicity are critical.

Availability

APX809S-29SR-7 is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, smart meter communication units, and automotive body control modules requiring stable component supply across extended temperature and long-lifecycle programs.

Supply support for APX809S-29SR-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 ICs, specializing in high-reliability power management, signal integrity, and protection solutions for industrial, computing, and automotive markets.

The APX809S/810S series belongs to Diodes' µP supervisory product line, engineered specifically for low-cost, low-power, single-threshold voltage monitoring in resource-constrained embedded systems.

FAQ

What is the exact reset threshold voltage of APX809S-29SR-7 at 25°C?

The APX809S-29SR-7 has a nominal reset threshold of 2.93V at +25°C, with a guaranteed range of 2.89V to 2.97V across production lots. This value is laser-trimmed during wafer sort and verified per DS39140 Rev. 2–2, Table 1, VTH row for -29 suffix.

Does APX809S-29SR-7 require an external capacitor for reset timing?

No. The 240ms minimum reset timeout is generated internally using a precision RC oscillator - no external capacitor or resistor is needed. This eliminates timing drift due to component tolerances and PCB parasitics, as confirmed in the Functional Block Diagram and Timing Diagram sections of DS39140.

Can APX809S-29SR-7 operate with a 1.8V supply rail?

No. While the device guarantees valid RESET logic states down to VCC = 1.0V, its reset function activates only when VCC falls below 2.93V. For 1.8V rail supervision, Diodes' APX809S-18SR-7 (1.8V threshold) is the correct variant - the -29 suffix explicitly denotes 2.93V detection.

Is the SOT23-SR package identical to SOT23-SA in footprint and thermal performance?

Yes. Both SOT23-SR and SOT23-SA share identical mechanical dimensions (2.9mm × 1.3mm), pad layout, and thermal resistance values (θJA = 232°C/W, θJC = 87°C/W). The SR/SA suffix denotes tape-and-reel orientation differences only - not package structure or solderability.