STMicroelectronics L78L24ABUTR

Overview

L78L24ABUTR from STMicroelectronics is a fixed-output +24 V, 100 mA positive linear voltage regulator in SOT-89 package, featuring thermal overload protection, short-circuit protection, and no external components required. It delivers stable local regulation for microcontroller peripherals, sensor interfaces, and industrial I/O modules where low quiescent current (6.5 mA typ.) and 200 µV output noise are critical.

For engineers reviewing the L78L24ABUTR datasheet, L78L24ABUTR pinout, L78L24ABUTR application, or L78L24ABUTR equivalent, this page provides verified technical context, real-world use cases, validated alternatives, and supply-chain support specific to the AB-grade (-40°C to +125°C) 24 V variant in SOT-89.

Technical Context

The L78L24ABUTR implements a three-terminal monolithic linear regulator architecture with internal current limiting and thermal shutdown. Its fixed 24 V output is trimmed at 25 °C to ±4% tolerance (AB grade), and it maintains regulation across input voltages from 27 V to 38 V with a 1.7 V dropout voltage.

It operates over -40°C to +125°C junction temperature, supports load currents up to 100 mA, and achieves 31–37 dB supply voltage rejection at 120 Hz with 40 mA load - enabling robust performance in noisy industrial power rails.

Key Specifications

Pinout & Package

SOT-89 package: surface-mount, 3-pin, thermally enhanced plastic case with exposed die attach pad (pin 2 connected internally to GND). Compact footprint (4.5 × 2.5 mm) suits space-constrained PCB layouts while enabling moderate power dissipation via copper pour.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM78L24ACZ/NOPB and MC78L24CP, the L78L24ABUTR offers tighter ±4% tolerance, guaranteed -40°C to +125°C operation, superior thermal resistance in SOT-89, and lower output noise - making it the only choice for new industrial, automotive, and medical designs demanding reliability across full environmental extremes.

Availability

L78L24ABUTR is available at Aetrix Electronics and suitable for industrial PLCs, automotive body electronics, medical sensor modules, and building automation controllers requiring stable component supply with long lifecycle assurance.

Supply support for L78L24ABUTR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, specializing in power management, microcontrollers, and analog ICs for industrial, automotive, and consumer markets.

The L78L series was designed as a drop-in replacement for discrete Zener/resistor regulators, delivering improved accuracy, lower quiescent current, and integrated protection - targeting cost-sensitive, space-constrained local regulation in embedded systems.

FAQ

What is the minimum input voltage required for regulation?

The L78L24ABUTR requires a minimum input voltage of 27 V to maintain regulation at full load, based on its 1.7 V dropout voltage specification. Below 27 V, output voltage drops linearly with input; operation below 27 V is not guaranteed and may cause undervoltage reset in downstream logic.

Can it drive a 100 mA load continuously in SOT-89 without a heatsink?

Yes, but only at ambient temperatures ≤55°C with ≥2 cm² of 2-oz copper connected to pin 2 (GND). At 100 mA and 27 V input, power dissipation is ~350 mW; thermal resistance junction-to-ambient is 55 °C/W in standard SOT-89, yielding ~19 °C rise - well within the -40°C to +125°C junction limit.

How does its 200 µV output noise compare to other 24 V regulators?

At 200 µV RMS (10 Hz–100 kHz), the L78L24ABUTR outperforms most legacy 78Lxx variants (e.g., LM78L24: ~350 µV) and matches mid-tier LDOs. This is achieved via optimized internal bandgap and error amplifier design - critical for analog signal chains where noise couples into measurement paths.

Is the SOT-89 package RoHS-compliant and lead-free?

Yes, the L78L24ABUTR in SOT-89 packaging is RoHS-compliant and lead-free per STMicroelectronics' ECOPACK2 specifications. The device carries the "TR" suffix indicating tape-and-reel packaging compatible with automated SMT assembly, and conforms to JEDEC J-STD-020 moisture sensitivity level 1.