Diodes Incorporated APX824-29W5G-7

Overview

APX824-29W5G-7 from Diodes Incorporated is a fixed-threshold processor supervisory circuit with active-high reset output, 2.93V negative-going supply voltage detection, 200ms typical reset delay, and integrated watchdog timer. It monitors VCC in DSP/microcontroller systems, asserts RESET during power-up below 1.1V, and reasserts on brownout or watchdog timeout. Used in industrial controls and portable equipment requiring reliable power sequencing.

For engineers reviewing the APX824-29W5G-7 datasheet, APX824-29W5G-7 pinout, APX824-29W5G-7 application, or APX824-29W5G-7 equivalent, key selection criteria include its 2.93V threshold accuracy over –40°C to +85°C, SOT25 package footprint, active-high reset logic, watchdog timeout of 1.6s typ., and 30μA supply current - all critical for low-power embedded reset integrity.

Technical Context

The APX824-29W5G-7 implements a precision bandgap-based voltage reference with 50mV hysteresis to reject noise-induced false resets. Its internal 200ms reset delay timer begins only after VCC exceeds the 2.93V threshold (VTH−), ensuring stable release after power stabilization.

Watchdog supervision operates independently: a missing edge transition at WDI within 1.6s (typ.) forces active-high RESET assertion, while MR is absent - confirming this variant lacks manual reset input. The device uses no external components and supports 2.5V–5V supply rails.

Key Specifications

Pinout & Package

SOT25 package: 5-pin, single-row, gull-wing lead frame; 3.0mm × 2.8mm body, 1.1mm height, 0.95mm lead pitch; 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 APX824-26W5G-7 and APX824-31W5G-7, the APX824-29W5G-7 offers optimal threshold alignment for 3.3V systems with typical ±5% tolerance, balancing noise immunity and early fault detection without requiring design-level voltage margin recalculations.

Availability

APX824-29W5G-7 is available at Aetrix Electronics and suitable for industrial automation, portable medical devices, and wireless sensor networks requiring stable component supply across extended production lifecycles.

Supply support for APX824-29W5G-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 ICs, specializing in high-reliability power management, signal integrity, and protection solutions.

The APX82x series belongs to Diodes' processor supervisory product line, designed specifically for deterministic power-on reset, brownout protection, and watchdog supervision in resource-constrained embedded systems.

FAQ

What is the function of Pin 5 (NC) on the APX824-29W5G-7?

Pin 5 is a no-connect terminal - internally unconnected and electrically isolated. It must remain unconnected on the PCB layout. This pin exists due to SOT25 package standardization across the APX823/APX824/APX825A family; APX824 variants do not use it for MR or any other function, unlike APX823 or APX825A.

Does the APX824-29W5G-7 require an external pull-up resistor on the RESET pin?

Yes - the RESET output is open-drain active-high. An external pull-up resistor (typically 10kΩ to VCC) is mandatory to establish a defined logic-high state when RESET is inactive. Without it, the output floats and cannot drive processor reset inputs reliably.

Can the watchdog timer be disabled without modifying the PCB?

Yes - leaving the WDI pin unconnected disables the watchdog function entirely. No external pull-up or pull-down is required; the internal input structure presents high impedance when idle, and the watchdog remains dormant until a valid edge transition occurs.

Is the 2.93V threshold specified at temperature extremes?

Yes - the datasheet specifies VTH− = 2.88V (min) to 3.00V (max) at 0°C to 85°C, and 2.80V to 3.05V over –40°C to +85°C. This 2.93V nominal value is guaranteed across the full industrial temperature range with ≤±70mV total variation, including hysteresis.