Diodes Incorporated APX803L-42W5-7

Overview

APX803L-42W5-7 from Diodes Incorporated is a micro-power voltage detector IC designed for µP supervisory circuits, monitoring VCC supply levels in embedded and battery-powered systems. It features a fixed 4.2V detection threshold (±1.5% accuracy), 1µA typical supply current, open-drain active-low RESET output, and 220ms reset timeout delay. Used in portable equipment where low quiescent power and precise brownout detection are critical.

For engineers reviewing the APX803L-42W5-7 datasheet, APX803L-42W5-7 pinout, APX803L-42W5-7 application, or APX803L-42W5-7 equivalent, key selection criteria include threshold voltage tolerance, reset delay stability over temperature, open-drain sink capability (3.5mA @ 0.4V), and compatibility with SOT25 footprint for space-constrained PCB layouts.

Technical Context

The APX803L-42W5-7 implements a precision bandgap-based voltage reference with internal hysteresis (0.01×VTH) to prevent oscillation during supply ramp-up/down. Its comparator continuously monitors VCC against the factory-trimmed 4.2V threshold and asserts RESET when VCC falls below that level.

Reset assertion remains active until VCC rises above the release voltage (VTH_H = VTH + VHYS), followed by a fixed 220ms timeout before deassertion - a timing value laser-trimmed at wafer test and stable across -40°C to +85°C ambient.

Key Specifications

Pinout & Package

SOT25 (5-pin) package with 1.6mm × 2.9mm footprint, thermal pad exposed on bottom for enhanced heat dissipation in high-density layouts. Pin 4 and Pin 5 are no-connect (NC) terminals - must be left floating or tied to GND per layout guidelines.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervisor applications.

Compared with APX803L20-42SA and TLV803E42DBZR, the APX803L-42W5-7 offers superior layout flexibility via its two NC pins for grounding or thermal relief, while maintaining identical core supervision functionality - making it optimal for production designs requiring mechanical robustness and thermal margin.

Availability

APX803L-42W5-7 is available at Aetrix Electronics and suitable for battery management systems, industrial PLC controllers, smart home sensor hubs, and medical wearable monitors requiring stable component supply throughout product lifecycles.

Supply support for APX803L-42W5-7 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 semiconductor manufacturer specializing in discrete, analog, and mixed-signal solutions for power management, signal integrity, and connectivity applications.

The APX803L series belongs to Diodes' precision voltage supervisor product line, engineered specifically for ultra-low-power, high-accuracy power monitoring in portable, industrial, and medical electronics where long-term reliability and tight threshold tolerance are mandatory.

FAQ

What is the function of Pins 4 and 5 on the APX803L-42W5-7?

Pins 4 and 5 are no-connect (NC) terminals - internally unconnected and electrically isolated. They may be left floating or tied to GND for mechanical stability and improved thermal conduction. Neither pin carries current or affects device operation, but grounding them enhances solder joint reliability and heatsinking in thermally demanding environments.

Does the APX803L-42W5-7 require an external capacitor for reset timing?

No. The 220ms reset timeout is internally generated and factory-laser-trimmed - no external RC network is needed. This eliminates component count, board space, and timing drift due to capacitor aging or temperature variation, ensuring consistent reset duration across all units and operating conditions.

Can the APX803L-42W5-7 monitor a 3.3V supply?

No - the APX803L-42W5-7 has a fixed 4.2V detection threshold and is not adjustable. For 3.3V supervision, Diodes offers the APX803L-33W5-7 (3.3V variant) or APX803L20-33SA (SOT23-3). Using the 4.2V part on a 3.3V rail would prevent RESET assertion entirely, as VCC never reaches the threshold.

How does the hysteresis affect system behavior during power-up?

The built-in 42mV hysteresis (0.01×4.2V) ensures the RESET signal remains asserted until VCC rises to ~4.242V after falling below 4.2V. This prevents oscillatory reset toggling during slow-ramping supplies or noisy VCC traces, guaranteeing clean, single-pulse reset assertion essential for deterministic µP boot sequences.