Diodes Incorporated APX803-29SRG-7

Overview

APX803-29SRG-7 from Diodes Incorporated is a 3-pin SOT23 open-drain microprocessor reset supervisor IC with 2.93V precision reset threshold, 140–280ms reset timeout (typ. 200ms), and guaranteed operation down to VCC = 1V. It monitors 3.3V digital systems, asserts active-low RESET during power-up/brownout, and requires no external components. Used in portable controllers and embedded µC power monitoring.

For engineers reviewing the APX803-29SRG-7 datasheet, APX803-29SRG-7 pinout, APX803-29SRG-7 application, or APX803-29SRG-7 equivalent, key selection factors include reset threshold accuracy (±0.04V), temperature-stable hysteresis (40mV), low 30µA supply current, open-drain output compatibility with bidirectional µP reset pins, and SOT23-SR package footprint.

Technical Context

The APX803-29SRG-7 implements a precision bandgap-based voltage comparator with internal 2.93V reference (±0.04V at +25°C) and 40mV hysteresis to reject supply noise. Its internal oscillator drives a fixed delay timer that holds RESET low for ≥140ms after VCC rises above threshold.

Designed for single-supply monitoring, it features an open-drain N-channel output stage capable of sinking ≥1.2mA at VCC = VTH − 0.2V with VOL ≤ 0.3V, and guarantees valid logic state down to VCC = 1V - enabling robust reset assertion during deep brownout recovery.

Key Specifications

Pinout & Package

APX803-29SRG-7 is housed in a RoHS-compliant, halogen-free SOT23-3 (SR package) with gull-wing leads, 2.4mm × 1.3mm body, and thermal resistance θJA = 201°C/W on standard FR-4 PCB.

Key Features

Applications

Equivalent & Alternatives

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

Compared with APX803D-29SRG-7 and TPS3808G33DBVR, APX803-29SRG-7 delivers optimal balance of long reset hold time, open-drain flexibility, ultra-low current, and drop-in SOT23-3 compatibility - making it ideal for cost-sensitive, space-constrained 3.3V µP systems requiring proven brownout immunity.

Availability

APX803-29SRG-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 ranges and multi-year production cycles.

Supply support for APX803-29SRG-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 APX803 product line delivers precision, low-cost microprocessor reset supervision for 1.1V–5.5V systems, targeting applications where deterministic power-on reset timing and brownout immunity are essential - especially in portable and thermally demanding environments.

FAQ

What is the exact reset threshold voltage and its tolerance for APX803-29SRG-7?

The APX803-29SRG-7 has a nominal reset threshold of 2.93V, with a guaranteed tolerance of ±0.04V at +25°C and full specification over -40°C to +85°C. This corresponds to a min/max range of 2.89V to 2.96V, providing precise supervision for 3.3V rails with adequate noise margin.

Does APX803-29SRG-7 require an external pull-up resistor on the RESET pin?

Yes - the RESET pin is open-drain active-low and requires an external pull-up resistor to a valid logic-high voltage (typically the same VCC rail or another compatible supply). A 10kΩ resistor to 3.3V is commonly used, enabling wired-OR configurations and level-shifting capability not possible with push-pull outputs.

Can APX803-29SRG-7 operate reliably below 1.1V VCC?

No - the recommended operating VCC range is 1.1V to 5.5V. While the device guarantees valid RESET output down to VCC = 1V, operation below 1.1V is outside specified conditions. Below 1V, the output becomes high-impedance and cannot actively drive low, risking undefined logic states on connected µP reset inputs.

How does the reset timeout behave during repeated voltage dips?

The internal timer resets to zero each time VCC falls below the 2.93V threshold. When VCC recovers above threshold, the timer restarts and holds RESET low for the full 140–280ms period. This ensures clean, glitch-free reset assertion even during multiple rapid brownouts, preventing partial µP initialization or corrupted memory writes.