Diodes Incorporated APX823-29W5G-7

Overview

APX823-29W5G-7 from Diodes Incorporated is a fixed-threshold processor supervisory IC with 2.93 V negative-going reset threshold, 200 ms reset delay, watchdog timer (1.6 s timeout), manual reset input, and active-low open-drain RESET output. It operates from 1.1 V to 5.5 V supply, draws 30 µA typical supply current, and is qualified for -40°C to +85°C ambient operation in SOT25 package. Used for power-on reset and voltage monitoring in microcontroller-based embedded systems.

For engineers reviewing the APX823-29W5G-7 datasheet, APX823-29W5G-7 pinout, APX823-29W5G-7 application, or APX823-29W5G-7 equivalent, key selection criteria include reset threshold accuracy (±50 mV hysteresis), MR input pull-up (60 kΩ), WDI transition sensitivity (50 ns min pulse width), and SOT25 thermal resistance (161 °C/W).

Technical Context

This device integrates a precision bandgap reference, comparator-based voltage monitor, RC-based 200 ms delay timer, and edge-triggered watchdog circuit with internal 1.6 s timeout. The reset assertion logic combines power-on detection (VCC > 1.1 V), undervoltage lockout (VTH− = 2.93 V), and manual reset override via MR pin.

The watchdog function resets on missing transitions at WDI (positive or negative edge), with no external components required. RESET output is open-drain, requiring an external pull-up; the MR input includes an internal 60 kΩ pull-up resistor and accepts standard CMOS logic levels.

Key Specifications

Pinout & Package

SOT25 (5-pin, surface-mount) package with 1.6 mm × 2.8 mm footprint, 0.95 mm pitch, and 161 °C/W junction-to-ambient thermal resistance. RoHS-compliant matte tin plating; moisture sensitivity level 3 per J-STD-020.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar processor supervision applications.

Compared with MAX809TRD2T and TPS3808G33DBVR, APX823-29W5G-7 uniquely combines 2.93 V threshold, integrated watchdog, manual reset with internal pull-up, and SOT25 compatibility-enabling compact, feature-complete supervision without external components.

Availability

APX823-29W5G-7 is available at Aetrix Electronics and suitable for industrial automation, portable medical devices, wireless sensor networks, and embedded networking equipment requiring stable component supply and long-term manufacturability.

Supply support for APX823-29W5G-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 APX823/APX824/APX825A family targets cost-sensitive, space-constrained embedded systems requiring robust power-on reset and watchdog supervision-designed specifically for DSP, microcontroller, and microprocessor platforms.

FAQ

What is the minimum VCC required to activate the power-on reset function?

The APX823-29W5G-7 asserts RESET when VCC rises above 1.1 V, initiating the reset sequence. This threshold is independent of the 2.93 V supervision level and ensures early reset assertion during power ramp-up, even before the main supply reaches regulation.

Can the watchdog timer be disabled without modifying the PCB layout?

Yes-leaving the WDI pin unconnected disables the watchdog function. The datasheet explicitly states that an open WDI input causes the watchdog to remain inactive, allowing the device to operate as a pure voltage supervisor with manual reset capability.

Is the RESET output compatible with 5 V logic systems when VCC = 3.3 V?

No-the RESET pin is open-drain and referenced to VCC. When VCC = 3.3 V, the output high level is limited to the external pull-up voltage (e.g., 5 V), but the low-level sink capability remains valid only up to VCC + 0.3 V per absolute maximum ratings. A level-shifter is required for safe 5 V interfacing.

How does the internal MR pull-up resistor affect button debounce requirements?

The 60 kΩ internal pull-up sets a weak default high state, making the MR pin susceptible to noise-induced glitches. External RC filtering (e.g., 100 nF capacitor to GND) is recommended to suppress bounce and ensure clean, single-shot reset assertion during mechanical switch actuation.