onsemi LM2931AT-5.0

Overview

LM2931AT-5.0 from onsemi is a fixed-output 5.0 V low-dropout (LDO) linear voltage regulator in TO-220 package, delivering ≥100 mA output current with dropout voltage as low as 0.16 V at 100 mA and ±3.8% output voltage tolerance over −40 °C to +125 °C. It features 60 V load dump protection, −50 V reverse transient immunity, and internal current limiting with thermal shutdown-designed for automotive power rails and battery-powered industrial systems requiring robust fault resilience.

For engineers reviewing the LM2931AT-5.0 datasheet, pinout, applications, or equivalent options, key selection considerations include its guaranteed 100 mA output under harsh transients, low 0.4 mA bias current at light load, compatibility with standard electrolytic/tantalum output capacitors, and TO-220 thermal performance (R_θJC = 5.0 °C/W) for passive heatsink integration.

Technical Context

The LM2931AT-5.0 employs a PNP pass transistor architecture enabling ultra-low dropout operation and inherent reverse-polarity blocking without external diodes. Its protection circuitry includes dedicated clamp networks for 60 V load dump and −50 V reverse input events, plus mirror-image insertion tolerance during board assembly.

Unlike standard LDOs, it integrates overvoltage shutdown (trip threshold 26–40 V), output inhibit capability (not used in fixed-output variants), and bias current regulation that remains stable across temperature (0.4–1.0 mA from −40 °C to +125 °C), making it suitable for unregulated 12 V/24 V automotive battery interfaces where input voltage can swing from −15 V to +40 V.

Key Specifications

Pinout & Package

LM2931AT-5.0 uses the TO-220 package (Case 221AB), with heatsink surface electrically connected to Pin 2 (Ground). The device has three terminals and is designed for vertical mounting with optional heatsinking.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with NCV2931AT-5.0, LM2931AT-5.0 offers identical performance but without AEC-Q100 certification overhead; versus LM2940CT-5.0, it delivers superior fault resilience and tighter initial accuracy at marginally higher cost-justifying use in safety-critical or unregulated-input applications.

Availability

LM2931AT-5.0 is available at Aetrix Electronics and suitable for automotive infotainment systems, engine control modules, and industrial data loggers requiring stable component supply with guaranteed long-term availability and automotive-grade reliability.

Supply support for LM2931AT-5.0 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.

The LM2931 series was developed specifically for automotive power conditioning-delivering ruggedized LDO regulation with integrated transient protection to replace discrete protection + regulation solutions in harsh 12 V/24 V systems.

FAQ

What is the maximum input voltage the LM2931AT-5.0 can handle continuously?

The LM2931AT-5.0 supports continuous input voltage up to 40 V DC. It also withstands transient inputs up to 60 V peak for ≤100 ms and reverse polarity inputs down to −50 V peak-key specifications enabling direct connection to automotive battery rails without external protection components.

Does the LM2931AT-5.0 require an external output capacitor, and what type is recommended?

Yes, the LM2931AT-5.0 requires an external output capacitor for stability. A minimum 100 µF aluminum electrolytic capacitor with ≤0.3 Ω ESR is recommended; solid tantalum (22–47 µF) is acceptable if ESR stays within 0.15 Ω. The device is not internally compensated, and omitting or undersizing CO risks oscillation, especially at low temperatures.

Is the LM2931AT-5.0 pin-compatible with standard 7805-style regulators?

No, the LM2931AT-5.0 is not pin-compatible with classic 7805 regulators. Its TO-220 pinout is Input–Ground–Output (Pin 1–2–3), whereas 78xx devices use Input–Ground–Output in the opposite order (Pin 1–2–3 = Output–Ground–Input). PCB layout must be verified before substitution.

What thermal performance can be expected from the LM2931AT-5.0 in TO-220 package?

In TO-220 (Case 221AB), the LM2931AT-5.0 has R_θJC = 5.0 °C/W and R_θJA = 65 °C/W (free-air, 25 °C ambient). With a modest 10 cm² copper pour and 1 mm thick heatsink, power dissipation can exceed 3 W-supporting 12 V→5 V conversion at 100 mA with <30 °C junction rise above ambient.

Does the LM2931AT-5.0 include output inhibit functionality?

No, the LM2931AT-5.0 is a fixed-output variant and does not include an output inhibit pin. That feature is exclusive to adjustable versions (e.g., LM2931CT-5.0) which have five pins and use Pin 2 as "Output Inhibit." The LM2931AT-5.0 has only three pins and operates continuously when powered within specification.