onsemi MC78L05ABPRE

Overview

MC78L05ABPRE from onsemi is a 5.0 V, 100 mA fixed-output linear voltage regulator in TO-92 package with internal short-circuit current limiting, thermal shutdown, and ±2% output voltage tolerance at +25°C. It operates over −40°C to +125°C and requires no external components for basic regulation in low-power microcontroller supply, sensor biasing, and industrial control I/O conditioning.

For engineers reviewing the MC78L05ABPRE datasheet, pinout, applications, or equivalent options, key selection criteria include dropout voltage (1.7 V typical), load regulation (≤30 mV over 1–40 mA), ripple rejection (49 dB at 120 Hz), thermal resistance (200°C/W in TO-92), and automotive-grade AEC-Q100 qualification for reliability-critical embedded systems.

Technical Context

The MC78L05ABPRE implements a monolithic series-pass transistor architecture with built-in bandgap reference, error amplifier, and protection circuitry. Its internal current limiting activates at ~150 mA, and thermal shutdown engages at ~150°C junction temperature - both self-resetting upon cooling.

It delivers stable 5.0 V output across input voltages from 7.0 V to 20 V (for AB-grade), with line regulation ≤45 mV and load regulation ≤30 mV under specified conditions. The device exhibits 40 µV RMS output noise (10 Hz–100 kHz) and maintains regulation down to 1.7 V headroom, making it suitable for battery-backed or unregulated DC rails where simplicity and ruggedness are prioritized over ultra-low quiescent current.

Key Specifications

Pinout & Package

MC78L05ABPRE uses the TO-92 plastic package (Case 029), with leads formed in straight or bent configuration per ordering suffix. Thermal performance assumes standard PCB mounting with minimal copper area; derating applies above 25°C ambient.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC78L05ACPG, MC78L05ABPRE provides guaranteed operation down to −40°C and AEC-Q100 qualification - critical for automotive and outdoor industrial use. Against NCV78L05ABPRAG, it offers identical regulation performance but in bulk packaging for lower-cost prototyping and low-volume production.

Availability

MC78L05ABPRE is available at Aetrix Electronics and suitable for microcontroller power supply, sensor biasing, industrial I/O conditioning, and automotive body electronics requiring stable component supply across temperature extremes and long lifecycle support.

Supply support for MC78L05ABPRE 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 manufacturer specializing in energy-efficient power management, analog, and sensor solutions for automotive, industrial, and cloud infrastructure markets.

The MC78L00A Series was designed as a cost-effective, rugged fixed-voltage linear regulator family targeting space-constrained, low-power embedded systems where simplicity, reliability, and wide temperature operation outweigh efficiency concerns.

FAQ

What is the maximum input voltage for MC78L05ABPRE?

The absolute maximum input voltage for MC78L05ABPRE is 35 V for 12–18 V output variants, but for the 5 V version specifically, the datasheet specifies 30 V as the absolute maximum rating. However, for reliable operation within specifications, the recommended input range is 7.0 V to 20 V - maintaining ≥2.0 V headroom above 5 V output while ensuring thermal limits are not exceeded at full load.

Does MC78L05ABPRE require input and output capacitors?

MC78L05ABPRE does not require external capacitors for basic stability, but input bypass (≥0.33 µF tantalum or low-ESR ceramic) is recommended when the regulator is located >10 cm from the power supply filter, and output bypass (≥0.1 µF ceramic) improves transient response. These values are validated in the standard application circuit of the official datasheet.

Is MC78L05ABPRE pin-compatible with other TO-92 linear regulators?

MC78L05ABPRE follows the industry-standard TO-92 pinout: Pin 1 = Output, Pin 2 = Ground, Pin 3 = Input. This matches LM78L05, UA78L05, and other legacy 78L05 variants - enabling direct replacement in existing designs without PCB modification, provided thermal and electrical requirements are verified.

What is the thermal resistance of MC78L05ABPRE in its TO-92 package?

The thermal resistance junction-to-ambient (R_θJA) for MC78L05ABPRE in TO-92 package is 200°C/W under standard test conditions (no heatsink, minimal PCB copper). This value assumes JEDEC-standard PCB layout; actual R_θJA improves with increased copper area - e.g., 2 oz. copper and 30 mm² pad can reduce it to ~120°C/W.

How does MC78L05ABPRE handle short-circuit conditions?

MC78L05ABPRE features internal short-circuit current limiting that restricts output current to approximately 150 mA during output-to-ground faults. Combined with thermal shutdown (triggering at ~150°C junction temperature), this dual-protection scheme prevents permanent damage and allows safe, self-resetting recovery once the fault is removed and temperature decreases.