onsemi MC78L24ABP

Overview

MC78L24ABP from onsemi is a 24 V, 100 mA fixed-output positive linear voltage regulator in TO-92 package, featuring internal short-circuit current limiting, thermal shutdown, and no external components required for basic operation. It delivers stable DC power in industrial control modules, sensor signal conditioning circuits, and low-power microcontroller supply rails where input-to-output differential voltage exceeds 1.7 V.

For engineers reviewing the MC78L24ABP datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed −40°C to +125°C operating temperature range, 24 V ±1 V output tolerance at 25°C, dropout voltage of 1.7 V, and thermal resistance of 200°C/W in TO-92 package.

Technical Context

The MC78L24ABP uses a monolithic bipolar linear regulator architecture with built-in thermal overload protection and foldback current limiting. Its internal circuitry maintains regulation across 28–38 V input range while delivering up to 100 mA load current.

It operates without external capacitors in many applications but benefits from 0.33 µF input and 0.1 µF output bypass capacitors for improved transient response and stability under dynamic loads. Ripple rejection is 31–45 dB at 120 Hz with 29–35 V input.

Key Specifications

Pinout & Package

MC78L24ABP is housed in a Pb-free TO-92 plastic package (Case 029), with leads bent for through-hole mounting. Thermal performance relies on PCB copper area and lead conduction; no heatsink pad is present.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC78L24ACPG and LM78L24ACZ, MC78L24ABP uniquely supports −40°C startup and operation while maintaining lower input bias current and full AEC-Q100 alignment via NCV variants-critical for automotive and industrial edge nodes.

Availability

MC78L24ABP is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, and medical sensor interface designs requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MC78L24ABP 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, delivering silicon solutions for automotive, industrial, cloud, and IoT applications.

The MC78LxxA series was designed as a cost-effective, rugged fixed-voltage linear regulator family for low-power embedded systems needing reliable DC-DC conversion without complex external circuitry.

FAQ

What is the minimum input voltage required for MC78L24ABP to maintain regulation?

The MC78L24ABP requires a minimum input voltage of 25.7 V under typical conditions, derived from its 24 V nominal output plus 1.7 V typical dropout voltage. At maximum load and elevated temperature, design margin should increase this to ≥26.5 V to ensure regulation across all operating conditions. The datasheet specifies 28 V as the lower limit of the recommended input range.

Does MC78L24ABP require input and output capacitors for stable operation?

MC78L24ABP does not require external capacitors for basic stability, but a 0.33 µF input capacitor is recommended when connected via long traces to the power source, and a 0.1 µF output capacitor improves transient response. These values are validated in the MC78L00A Series datasheet Figure 2 and Applications Information section.

Is MC78L24ABP pin-compatible with other regulators in the MC78LxxA family?

Yes, MC78L24ABP shares identical TO-92 pinout (Pin 1 = Output, Pin 2 = Ground, Pin 3 = Input) with all MC78LxxA variants including MC78L05ABP, MC78L12ABP, and MC78L15ABP-enabling drop-in replacement across output voltages when board layout accommodates thermal requirements.

What is the thermal resistance and maximum power dissipation of MC78L24ABP in TO-92 package?

MC78L24ABP has a junction-to-ambient thermal resistance (R_JA) of 200°C/W in TO-92 package. At 25°C ambient, its maximum power dissipation is 625 mW, calculated as (150°C − 25°C) / 200°C/W. Derating is required above 25°C ambient per Figure 7 in the datasheet.

How does MC78L24ABP handle overcurrent and overtemperature faults?

MC78L24ABP incorporates internal foldback current limiting that reduces output current during short-circuit events, and thermal shutdown that disables the output when junction temperature exceeds ~150°C. Both protections are fully integrated-no external components needed-and recovery is automatic once fault conditions subside.