Diodes Incorporated APX803S05-44SR-7

Overview

APX803S05-44SR-7 from Diodes Incorporated is a 3-pin SOT23 open-drain microprocessor reset supervisor IC designed for 5.0V supply monitoring. It asserts an active-low RESET signal during power-up and brownout events, with a typical timeout of 50ms and a precision reset threshold of 4.38V (±0.07V). Guaranteed operation down to VCC = 1V and 10µA supply current make it suitable for portable and battery-powered embedded systems.

For engineers reviewing the APX803S05-44SR-7 datasheet, APX803S05-44SR-7 pinout, APX803S05-44SR-7 application, or APX803S05-44SR-7 equivalent, key selection criteria include reset threshold accuracy (4.31–4.45V), open-drain output compatibility with bidirectional µP reset pins, fixed 50ms timeout timing, and guaranteed reset validity at VCC ≥ 1V in industrial temperature range (−40°C to +85°C).

Technical Context

The APX803S05-44SR-7 implements a precision voltage comparator with internal hysteresis and a fixed-delay timer. Its reset assertion logic responds to VCC falling below 4.38V (typ.) and holds RESET low for ≥20ms and ≤70ms after VCC rises above threshold - with 50ms typical timeout per ordering code "05".

It features an open-drain output stage compatible with external pull-up to any logic rail up to 5.5V, supports sink currents up to 3.5mA at 0.4V, and maintains valid reset state across −40°C to +85°C ambient with <30ppm/°C tempco on reset threshold.

Key Specifications

Pinout & Package

APX803S05-44SR-7 is housed in a RoHS-compliant SOT23-3 (SR package) with gull-wing leads and standard 0.95mm pitch. The SR variant uses pin 1 = GND, pin 2 = VCC, pin 3 = RESET (open-drain active-low).

Key Features

Applications

Equivalent & Alternatives

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

Compared with APX803S05-44SA-7, the SR variant offers identical supervision performance but with inverted pinout for mechanical compatibility with specific layout constraints; compared with MAX809SEUR+T, it trades longer timeout and push-pull drive for open-drain versatility and tighter threshold tolerance at lower quiescent current.

Availability

APX803S05-44SR-7 is available at Aetrix Electronics and suitable for industrial PLC controllers, portable medical monitors, embedded network routers, and smart energy meters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for APX803S05-44SR-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 microprocessor reset applications demanding accuracy, low power, and industrial temperature operation.

FAQ

What is the exact reset threshold voltage for APX803S05-44SR-7?

The APX803S05-44SR-7 has a nominal reset threshold of 4.38V, with guaranteed min/max values of 4.31V and 4.45V at +25°C. This threshold is fully specified over −40°C to +85°C with a tempco of ≤30ppm/°C, ensuring stable 5.0V supply monitoring across industrial environments.

Can APX803S05-44SR-7 drive a reset line shared with other open-drain devices?

Yes - its open-drain active-low RESET output supports wired-OR configurations. Multiple APX803S05-44SR-7 units or other open-drain supervisors can share a single reset bus using one external pull-up resistor, enabling coordinated system-level reset assertion without contention.

Does APX803S05-44SR-7 remain functional when VCC drops below 1.0V?

No - the device guarantees correct RESET logic state only for VCC ≥ 1.0V. Below 1.0V, the internal circuitry ceases operation and RESET becomes high-impedance. This is intentional design behavior aligned with most µPs being nonfunctional below 1.0V, avoiding false releases.

How does the 50ms timeout differ from the 240ms version in the same family?

The "05" suffix denotes a 50ms (typ.) reset timeout, optimized for fast-boot µPs like ARM Cortex-M series. In contrast, the base APX803S-44SR-7 (no "05") provides 240ms (typ.) timeout for legacy 8-bit µCs requiring longer initialization. Both share identical threshold, supply current, and temperature specs.