Diodes Incorporated APX803S-23SA-7

Overview

APX803S-23SA-7 from Diodes Incorporated is a 3-pin SOT23 open-drain microprocessor reset supervisor IC with 2.25 V reset threshold, 240 ms minimum reset timeout, 10 µA typical supply current, and guaranteed operation down to V_CC = 1 V. It monitors 2.5 V/3.0 V/3.3 V/5.0 V power rails in embedded microcontroller systems requiring reliable brownout detection and power-on reset assertion.

For engineers reviewing the APX803S-23SA-7 datasheet, APX803S-23SA-7 pinout, APX803S-23SA-7 application, or APX803S-23SA-7 equivalent, key selection criteria include reset threshold accuracy (±20 mV at +25°C), open-drain output compatibility with bidirectional MCU reset pins, temperature-stable timing (30 ppm/°C tempco), and low-voltage validity for battery-backed systems.

Technical Context

The APX803S-23SA-7 implements a precision bandgap-based voltage comparator with hysteresis to detect V_CC drops below 2.25 V, triggering an active-low open-drain RESET signal. Its internal timer ensures minimum 140 ms (typ. 240 ms) assertion after V_CC recovers above threshold.

Designed for immunity to fast transients, it guarantees correct logic state for V_CC ≥ 1 V and disables sink capability only below 1 V. The SA package variant uses Pin 1 = GND, Pin 2 = V_CC, Pin 3 = RESET - distinct from SR pinout.

Key Specifications

Pinout & Package

SOT23-3 (SA package): ultra-compact 2.9 mm × 1.3 mm surface-mount package with gull-wing leads, optimized for high-density PCB layouts and reflow soldering.

Key Features

Applications

Equivalent & Alternatives

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

Compared with APX809S-23SA-7 and MAX809TRD2T, the APX803S-23SA-7 uniquely balances open-drain flexibility, industrial temperature stability, and proven brownout immunity-making it optimal for multi-rail systems requiring shared reset coordination.

Availability

APX803S-23SA-7 is available at Aetrix Electronics and suitable for industrial PLC controllers, portable medical sensors, automotive body control modules, and smart energy meters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for APX803S-23SA-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' supervisory IC product line, engineered specifically for deterministic power-on reset and brownout protection in resource-constrained embedded systems operating across –40°C to +85°C.

FAQ

What is the exact reset threshold voltage and its tolerance for APX803S-23SA-7?

The APX803S-23SA-7 has a nominal reset threshold of 2.25 V, with a guaranteed range of 2.21 V to 2.30 V at +25°C. Over the full –40°C to +85°C operating range, the threshold drift is limited to ±30 ppm/°C, resulting in ≤±25 mV total variation - sufficient for reliable 2.5 V rail supervision with safety margin.

Can APX803S-23SA-7 drive a reset line directly without a pull-up resistor?

No - the APX803S-23SA-7 features an open-drain RESET output and requires an external pull-up resistor to a valid logic-high voltage (e.g., MCU V_DD). Typical values range from 10 kΩ to 100 kΩ depending on bus capacitance and rise-time requirements. This architecture enables wired-OR configurations and voltage-level translation.

How does the reset timeout behave during repeated brownout events?

Each time V_CC falls below the 2.25 V threshold, the internal timer resets and forces RESET low immediately. The 240 ms timeout period begins anew only after V_CC rises above threshold and remains stable. This ensures continuous reset assertion during sustained undervoltage conditions - critical for preventing partial MCU execution.

Is APX803S-23SA-7 compatible with microcontrollers that have bidirectional reset pins?

Yes - the open-drain output allows direct connection to bidirectional reset pins (e.g., Motorola 68HC11, STM32L0x). With a single pull-up resistor, either the APX803S or the MCU can assert reset, enabling coordinated system recovery without additional logic or isolation components.