onsemi MC78L05ACPRP

Overview

MC78L05ACPRP from onsemi is a 5.0 V, 100 mA fixed-output linear voltage regulator in TO-92 package with internal short-circuit current limiting and thermal overload protection. It operates over 0°C to +125°C junction temperature, requires no external components for basic regulation, and delivers stable output with ±2.5% initial tolerance (4.75–5.25 V) under load and line variations.

For engineers reviewing the MC78L05ACPRP datasheet, pinout, applications, or equivalent options, key selection factors include dropout voltage (1.7 V typical), ripple rejection (41–49 dB at 120 Hz), output noise (40 µV RMS), thermal resistance (200°C/W in TO-92), and compatibility with low-cost, space-constrained embedded power rails.

Technical Context

The MC78L05ACPRP uses a monolithic silicon design with built-in current limiting and thermal shutdown circuitry, eliminating need for external protection components. Its internal topology includes a reference amplifier, error amplifier, pass transistor, and bias network - all integrated into a single die without external feedback resistors.

It functions as a three-terminal positive regulator requiring common ground between input and output. Input voltage must remain ≥2.0 V above output (i.e., ≥7.0 V minimum for 5 V output) even at ripple troughs, and stability is maintained without output capacitance - though 0.1 µF improves transient response.

Key Specifications

Pinout & Package

MC78L05ACPRP is housed in a Pb-free TO-92 plastic package (Case 029), with 3 leads and through-hole mounting. Thermal resistance is 200°C/W junction-to-ambient (no heatsink).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC78L05ACPREG, MC78L05ACPRP offers identical performance in ammo-pack form factor ideal for low-volume prototyping; versus LM78L05ACZ, it delivers superior ripple rejection and lower dropout - critical for marginal input conditions and noise-sensitive analog loads.

Availability

MC78L05ACPRP is available at Aetrix Electronics and suitable for industrial sensor nodes, consumer remote controls, automotive body electronics, and legacy PLC I/O modules requiring stable component supply and long-term manufacturability.

Supply support for MC78L05ACPRP 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, with leadership in power management, analog, and sensing technologies.

The MC78L00A series was designed for cost-sensitive, low-power embedded systems requiring simple, robust, fixed-output regulation - especially where board space, BOM count, and thermal simplicity are prioritized over adjustable output or ultra-low quiescent current.

FAQ

What is the maximum input voltage rating for MC78L05ACPRP?

The absolute maximum input voltage for MC78L05ACPRP is 30 V DC when operating at output voltages from 5.0 V to 9.0 V. Exceeding this rating risks permanent device failure due to junction breakdown or thermal runaway, regardless of load condition or ambient temperature.

Does MC78L05ACPRP require input and output capacitors for stable operation?

MC78L05ACPRP does not require output capacitance for stability, but a 0.1 µF ceramic capacitor is recommended to improve transient response. An input bypass capacitor (≥0.33 µF tantalum or low-ESR ceramic) is required if the regulator is located more than a few inches from the power supply filter to prevent oscillation under dynamic load.

What is the thermal resistance (R_JA) of MC78L05ACPRP in its TO-92 package?

The junction-to-ambient thermal resistance (R_JA) of MC78L05ACPRP in the TO-92 package is 200°C/W with no heatsink and standard PCB copper. This value assumes minimal copper area; adding 1 in² of 2 oz. copper on the GND lead can reduce R_JA significantly - see Figure 7 in the datasheet for derating curves.

Can MC78L05ACPRP be used as a current source?

Yes, MC78L05ACPRP can be configured as a constant-current source by connecting a resistor between output and load return, with the load referenced to ground. The current equals (5.0 V + I_IB) / R, where I_IB ≈ 3.8 mA. For example, a 50 Ω resistor yields ~100 mA output - but power dissipation in both resistor and MC78L05ACPRP must be verified within ratings.

Is MC78L05ACPRP qualified for automotive applications?

No, MC78L05ACPRP is rated for 0°C to +125°C junction temperature and is not AEC-Q100 qualified. For automotive use, select NCV78L05ABPG or NCV78L05ABPRAG - these carry the NCV prefix, undergo automotive-grade qualification, and guarantee operation from −40°C to +125°C with PPAP documentation support.