onsemi LM2931ACTV

Overview

LM2931ACTV from onsemi is an adjustable-output LDO voltage regulator with 60 V load dump protection, 100 mA output current capability, and <0.6 V dropout at 100 mA - designed for automotive and industrial battery-powered systems requiring robust fault tolerance and extended runtime.

For engineers reviewing the LM2931ACTV datasheet, pinout, applications, or equivalent options, key selection criteria include its adjustable output range (3.0–24 V), output inhibit function, ±2.5% reference accuracy, and TO-220-5 package with heatsink-connected ground pin.

Technical Context

The LM2931ACTV implements a PNP pass transistor architecture enabling ultra-low dropout and reverse-polarity survivability down to −50 V. Its internal 1.20 V reference (±2.5%) feeds an external resistor divider to set output voltage, while the dedicated inhibit pin enables microprocessor-controlled power gating with defined turn-on/turn-off thresholds (2.15 V / 2.50 V typical).

It integrates six protection mechanisms: thermal shutdown, internal current limiting, overvoltage shutdown (26–40 V), reverse transient immunity, mirror-image insertion tolerance, and load dump survival up to 60 V - all without external components beyond input/output capacitors and feedback resistors.

Key Specifications

Pinout & Package

LM2931ACTV uses the TO-220-5 package (Case 314B), with the metal tab thermally and electrically connected to Pin 3 (Ground). The package supports vertical mounting with heatsinking via the tab.

Key Features

Applications

Equivalent & Alternatives

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

Compared with NCV2931ACDT5G and LM2931CDT-3.3G, the LM2931ACTV uniquely combines through-hole mechanical robustness, heatsink-enabled thermal performance, adjustable output, and digital inhibit - making it optimal for prototyping, service replacement, and high-reliability under-hood applications where layout flexibility and configurability are prioritized.

Availability

LM2931ACTV is available at Aetrix Electronics and suitable for automotive body electronics, industrial handheld instrumentation, and telematics control units requiring stable component supply with long lifecycle assurance.

Supply support for LM2931ACTV 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 focused on energy-efficient electronics for automotive, industrial, cloud, and IoT applications.

The LM2931 series was engineered specifically for harsh automotive environments - delivering load dump resilience, reverse polarity survival, and wide-temperature operation to replace legacy regulators in safety-critical and always-on vehicle systems.

FAQ

What is the maximum input voltage the LM2931ACTV can withstand during load dump events?

The LM2931ACTV is rated for 60 V transient input voltage (≤100 ms duration) per ISO 7637-2 Pulse 5a. This allows direct connection to vehicle battery rails without external TVS diodes in most automotive applications. Continuous input must remain ≤40 V. The device automatically recovers after transient clearance without latch-up or parameter shift.

Does the LM2931ACTV require an external capacitor for stability, and what type is recommended?

Yes, the LM2931ACTV requires an external output capacitor for stability - it is not internally compensated. A minimum 10 µF electrolytic or tantalum capacitor with ESR ≤0.3 Ω is recommended. For best noise performance and cold-temperature stability, solid tantalum or polymer capacitors are preferred over standard aluminum electrolytics below −25°C.

How does the output inhibit function of the LM2931ACTV behave during power-up and power-down sequences?

The LM2931ACTV output inhibit pin is active-high: output is enabled when voltage ≥2.15 V (typ) and disabled when ≤1.20 V (min over temp). During power-up, output remains off until inhibit pin reaches threshold; during power-down, output shuts off cleanly before supply collapse. No external pull-up is required - internal bias ensures defined state at power-on reset.

Can the LM2931ACTV be used to generate a 2.5 V output, and what resistor values are needed?

Yes, the LM2931ACTV supports 2.5 V output using its adjustable configuration. With V_ref = 1.20 V, use R1 = 1.2 kΩ (between output and adjust) and R2 = 1.3 kΩ (between adjust and ground). This yields V_OUT = 1.20 × (1 + R1/R2) ≈ 2.5 V. Resistor tolerance should be ≤1% to maintain accuracy within ±2.5% total.

Is the LM2931ACTV pin-compatible with other TO-220-5 LDOs such as the LM2940CT-5.0?

No, the LM2931ACTV is not pin-compatible with LM2940CT-5.0 or other fixed-output TO-220-5 regulators. Its Pin 1 is Adjust (not NC), Pin 2 is Output Inhibit (not Ground), and Pin 3 is Ground (heatsink-connected). Substituting without board revision will cause functional failure. Use only verified alternatives like NCV2931ACDT5G (DPAK-5) or LM2931CDT-3.3G (same package, fixed output) with confirmed pin mapping.