onsemi MC78L08ABP

Overview

MC78L08ABP from onsemi is a 100 mA, fixed +8.0 V positive linear voltage regulator in TO-92 package, featuring internal short-circuit current limiting, thermal shutdown, and dropout voltage of 1.7 V at 25°C. It operates across −40°C to +125°C and requires no external components for basic regulation in low-power analog or digital supply rails.

For engineers reviewing the MC78L08ABP datasheet, pinout, applications, or equivalent options, this page delivers verified electrical specs (VO = 7.7–8.3 V, RR = 37–57 dB, Regload ≤ 80 mV), thermal resistance (R_JA = 200°C/W), and direct substitution guidance for industrial control, sensor interface, and legacy system replacement.

Technical Context

The MC78L08ABP implements a monolithic series-pass regulator architecture with built-in protection circuitry: thermal overload shutdown activates at ~150°C junction temperature, and current limiting caps output at ~150 mA. Its internal reference and error amplifier maintain regulation without external feedback components.

Designed for simplicity and ruggedness, it delivers stable +8.0 V output under load currents from 1.0 mA to 100 mA, with line regulation ≤125 mV over 11–23 V input range and load regulation ≤40 mV across full load range at 25°C - enabling use in battery-powered instrumentation and automotive body electronics where minimal BOM count is critical.

Key Specifications

Pinout & Package

MC78L08ABP uses the TO-92 (Case 029) plastic package with straight leads and Pb-free finish. Thermal performance relies on PCB copper area; no heatsink required for ≤100 mW dissipation at room ambient.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC78L08ACPG, the MC78L08ABP offers extended low-temperature capability essential for harsh environments; versus NCV78L08ABPRPG, it lacks AEC-Q100 certification but provides identical electrical and thermal performance at lower cost for non-automotive industrial use.

Availability

MC78L08ABP is available at Aetrix Electronics and suitable for industrial sensor interface, automotive body control modules, and legacy equipment replacement requiring stable component supply and long-term obsolescence management.

Supply support for MC78L08ABP 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 delivering energy-efficient silicon solutions for automotive, industrial, cloud, medical, and IoT applications.

The MC78L00A Series was designed as a cost-effective, robust fixed-output linear regulator family for low-current applications where simplicity, reliability, and wide temperature operation are prioritized over ultra-low dropout or high PSRR.

FAQ

What is the maximum input voltage for MC78L08ABP?

The absolute maximum input voltage for MC78L08ABP is 35 V for 12–18 V rated versions, per datasheet Absolute Maximum Ratings. However, for reliable operation within specifications, input should remain between 10.5 V and 23 V to maintain regulation and avoid excessive power dissipation. Exceeding 23 V risks thermal shutdown or reduced lifetime due to elevated junction temperature.

Does MC78L08ABP require input and output capacitors?

MC78L08ABP does not require capacitors for basic stability, but a 0.33 µF input bypass capacitor is recommended if the regulator is located far from the power supply filter or driving large capacitive loads. A 0.1 µF output capacitor improves transient response. These values are specified in the standard application circuit and validated across the −40°C to +125°C operating range for MC78L08ABP.

What is the dropout voltage of MC78L08ABP and how does it affect design?

The dropout voltage of MC78L08ABP is 1.7 V typical at 25°C and 100 mA load. This means the input must exceed 9.7 V to sustain 8.0 V output under full load. At lighter loads, dropout decreases - e.g., ~1.3 V at 40 mA. Designers must ensure minimum input voltage (including ripple and sag) stays ≥ VO + dropout to avoid regulation loss, especially in battery-fed systems.

Can MC78L08ABP be used in automotive applications?

Yes, MC78L08ABP is rated for −40°C to +125°C operation and features thermal shutdown and short-circuit protection, making it suitable for non-safety-critical automotive body electronics such as mirror controls or lighting modules. For certified automotive programs requiring AEC-Q100 qualification and PPAP, the NCV78L08ABPRPG variant is the designated alternative - MC78L08ABP itself is not AEC-Q100 qualified.

How does MC78L08ABP compare to switching regulators in efficiency?

MC78L08ABP is a linear regulator and inherently less efficient than switching alternatives - e.g., at 12 V input and 100 mA output, its power loss is (12 V − 8 V) × 0.1 A = 400 mW, resulting in ~67% efficiency. Switching regulators achieve >85% efficiency in the same condition. MC78L08ABP is selected for low noise, simplicity, and EMI-free operation - not efficiency - in sub-100 mA applications where heat dissipation is manageable.