Diodes Incorporated APX803S-29SA-7

Overview

APX803S-29SA-7 from Diodes Incorporated is a 3-pin microprocessor supervisory IC with open-drain active-low RESET output, precision 2.93V reset threshold (±0.04V), 240ms minimum reset timeout, 10µA typical supply current, and guaranteed operation down to VCC = 1V - used for power-on/brownout reset assertion in 3.3V digital systems including microcontrollers and embedded controllers.

For engineers reviewing the APX803S-29SA-7 datasheet, APX803S-29SA-7 pinout, APX803S-29SA-7 application, or APX803S-29SA-7 equivalent, key selection criteria include reset threshold accuracy at temperature, open-drain drive capability into µP bidirectional reset pins, low-voltage validity (1V), and SOT23-3 SA package compatibility with space-constrained portable designs.

Technical Context

The APX803S-29SA-7 integrates a precision voltage comparator monitoring VCC against a trimmed 2.93V reference and an internal timer that asserts RESET low for ≥240ms after VCC rises above threshold. It ignores fast transients via dVCC/dt immunity up to 100 V/µs and maintains valid logic state down to 1V supply.

Its open-drain RESET output requires an external pull-up and supports level-shifting across supply domains - enabling single-reset-line supervision of multiple supplies or interfacing with µPs having bidirectional reset pins (e.g., Motorola 68HC11) using one shared pull-up resistor.

Key Specifications

Pinout & Package

APX803S-29SA-7 is housed in a RoHS-compliant SOT23-3 (SA) package with gull-wing leads, 2.4mm body length, and 0.915mm lead pitch - optimized for automated placement and reflow in high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with APX809S-29SA-7 and MAX809SEUR+T, the APX803S-29SA-7 uniquely combines open-drain output, 240ms timeout, and 10µA supply current - making it optimal for multi-rail systems, bidirectional µP interfaces, and portable designs needing both timing margin and wiring flexibility.

Availability

APX803S-29SA-7 is available at Aetrix Electronics and suitable for industrial PLC controllers, portable medical monitors, smart energy meters, and automotive body control modules requiring stable component supply across extended temperature and long-lifecycle programs.

Supply support for APX803S-29SA-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 APX803S series belongs to Diodes' µP supervisory product line, engineered specifically for cost-sensitive, space-constrained applications requiring precision voltage monitoring and robust reset generation without external components.

FAQ

What is the exact reset threshold voltage for APX803S-29SA-7 and how does it vary with temperature?

The APX803S-29SA-7 has a nominal reset threshold of 2.93V at +25°C, with a guaranteed range of 2.89V to 2.97V. Its temperature coefficient is ≤30 ppm/°C, resulting in a maximum deviation of ±11.7mV over –40°C to +85°C - confirmed by Figure 1 in DS39161 Rev. 2–2.

Can APX803S-29SA-7 drive a reset line shared among multiple microcontrollers?

Yes - its open-drain RESET output supports wired-OR configuration. Multiple APX803S-29SA-7 devices (or other open-drain supervisors) can share one pull-up resistor to a common logic rail, enabling coordinated reset assertion across subsystems without contention.

Does APX803S-29SA-7 require an external capacitor for reset timing?

No - the 240ms reset timeout is generated by an internal RC timer. No external capacitor or resistor is needed, reducing BOM count and PCB area versus RC-based reset circuits, and eliminating timing drift due to component tolerances.

Is APX803S-29SA-7 compatible with 1.8V microcontrollers?

It is not directly compatible as a reset source for 1.8V µPs because its RESET output is referenced to VCC (3.3V domain). However, it can supervise the 3.3V supply feeding a level shifter that drives the 1.8V µP's reset pin - leveraging its open-drain output for clean level translation.