Diodes Incorporated APX803S-23SR-7

Overview

APX803S-23SR-7 from Diodes Incorporated is a 3-pin SOT23 open-drain microprocessor reset supervisor IC designed for precise 2.25 V supply monitoring in embedded systems. It asserts an active-low RESET signal during power-up, brownout, or voltage drop below threshold, maintains reset for ≥140 ms after recovery, guarantees valid output down to VCC = 1 V, and draws only 10 µA typical supply current - ideal for battery-powered controllers and portable instrumentation.

For engineers reviewing the APX803S-23SR-7 datasheet, APX803S-23SR-7 pinout, APX803S-23SR-7 application, or APX803S-23SR-7 equivalent, key selection factors include its 2.25 V reset threshold tolerance (±0.04 V), 240 ms typical timeout, open-drain output compatibility with bidirectional µP reset pins, and guaranteed operation across –40°C to +85°C.

Technical Context

The APX803S-23SR-7 implements a precision bandgap-based voltage comparator with 30 ppm/°C tempco to monitor VCC against a fixed 2.25 V threshold. Its internal timer initiates only after VCC rises above VTH and holds RESET low for a fixed timeout period - independent of VCC slew rate or noise transients.

This variant uses the SR pinout configuration (Pin 1 = GND, Pin 2 = VCC, Pin 3 = RESET) and features an open-drain output stage compatible with external pull-up to any logic rail up to 5.5 V. RESET remains valid and actively driven low for VCC ≥ 1 V; below 1 V, the output enters high-impedance state.

Key Specifications

Pinout & Package

SOT23-3 (SR package): ultra-compact surface-mount plastic package with 2.9 mm × 1.3 mm footprint, 0.95 mm height, and thermal resistance θJA = 232 °C/W - optimized for space-constrained PCB layouts and automated assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with APX809S-23SR-7, the APX803S-23SR-7 enables shared reset busing and mixed-voltage interfacing; compared with MAX809TRD3T, it offers halogen-free construction and guaranteed reset validity down to 1 V - critical for fail-safe brownout response.

Availability

APX803S-23SR-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 and long-term lifecycle support.

Supply support for APX803S-23SR-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' precision voltage supervisor product line, engineered specifically for cost-sensitive, space-constrained embedded systems requiring guaranteed reset behavior across wide temperature and voltage ranges.

FAQ

What is the exact reset threshold voltage for APX803S-23SR-7?

The APX803S-23SR-7 has a nominal reset threshold of 2.25 V, with guaranteed limits of 2.21 V (min) and 2.30 V (max) at +25°C. Over the full –40°C to +85°C operating range, the tempco is ≤30 ppm/°C, resulting in worst-case threshold deviation of ±0.015 V across temperature.

Can APX803S-23SR-7 drive a reset line shared among multiple microcontrollers?

Yes - its open-drain RESET output supports wired-OR configuration. Multiple APX803S-23SR-7 units (or other open-drain reset sources) can share a single reset bus with one external pull-up resistor. This enables coordinated reset assertion across subsystems without logic contention.

Does APX803S-23SR-7 require an external capacitor for timing?

No - the 240 ms typical reset timeout is generated by an internal RC timer. No external timing capacitor or resistor is needed, reducing BOM count and PCB area. The timeout is factory-trimmed and specified from 140 ms (min) to 280 ms (max) across temperature and voltage.

How does APX803S-23SR-7 behave when VCC falls below 1 V?

Below 1 V, the internal circuitry ceases operation and the RESET pin transitions to high-impedance (open-circuit) state. It no longer actively drives low, so the external pull-up determines the logic level. This is intentional - most µPs are non-functional below 1 V, making further reset assertion unnecessary.