onsemi MC78L15ABPRA

Overview

MC78L15ABPRA from onsemi is a 15 V, 100 mA fixed-output linear voltage regulator in TO-92 package with internal short-circuit current limiting and thermal shutdown protection. It delivers stable DC power for low-current analog circuits, sensor interfaces, and microcontroller peripherals where input-to-output differential voltage exceeds 1.7 V.

For engineers reviewing the MC78L15ABPRA datasheet, pinout, applications, or equivalent options, key selection criteria include output voltage tolerance (±4%), dropout voltage (1.7 V typ), thermal resistance (200 °C/W), and −40°C to +125°C operating temperature range.

Technical Context

The MC78L15ABPRA uses a monolithic bipolar silicon design with built-in thermal overload protection and internal current limiting. Its regulation architecture relies on a precision bandgap reference and error amplifier driving a pass transistor, enabling stable output without external compensation components in most applications.

It operates with a minimum input voltage of 17.5 V (to maintain 15 V output under load) and supports up to 100 mA continuous output current. Input bias current remains below 6.5 mA over temperature, and ripple rejection reaches 34 dB at 120 Hz with 18.5–28.5 V input.

Key Specifications

Pinout & Package

MC78L15ABPRA is housed in a Pb-free TO-92 package (Case 029), with leads formed straight for bulk or tape-and-reel packaging. 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 MC78L15ACPG, MC78L15ABPRA enables cold-temperature startup in harsh environments; compared with NCV78L15ABPRAG, it reduces qualification burden while retaining identical performance and ruggedness for non-automotive applications.

Availability

MC78L15ABPRA is available at Aetrix Electronics and suitable for industrial sensor interfaces, automotive body control modules, legacy instrumentation power, and microcontroller peripheral supply requiring stable component supply across extended temperature ranges.

Supply support for MC78L15ABPRA 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, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The MC78L00A Series was designed as a cost-effective, rugged fixed-output linear regulator family targeting low-current applications where simplicity, reliability, and wide temperature operation outweigh efficiency concerns.

FAQ

What is the maximum input voltage for MC78L15ABPRA?

The absolute maximum input voltage for MC78L15ABPRA is 40 V DC, as specified in the Absolute Maximum Ratings table. However, for reliable operation within its 15 V output specification and thermal limits, the recommended maximum input is 30 V - ensuring sufficient headroom above the 1.7 V dropout while maintaining junction temperature below 150°C under full 100 mA load in TO-92 packaging.

Does MC78L15ABPRA require an input bypass capacitor?

Yes, MC78L15ABPRA requires a 0.33 µF input bypass capacitor when connected via long traces or wires to the power supply filter, per the Applications Information section. This capacitor stabilizes operation by reducing high-frequency impedance and preventing oscillation. Tantalum, mylar, or ceramic types with low ESR are recommended and must be mounted directly across pins 3 (VIN) and 2 (GND) with minimal lead length.

Can MC78L15ABPRA be used as a current source?

Yes, MC78L15ABPRA can be configured as a constant-current source using an external resistor between output and load, as shown in Figure 9 of the datasheet. With the regulator's internal reference and pass transistor, current equals (15 V − V_BE) / R, where V_BE ≈ 0.7 V for a typical NPN transistor. For example, a 143 Ω resistor yields ~100 mA. Dissipation must be verified to avoid exceeding thermal limits.

What is the thermal resistance of MC78L15ABPRA in TO-92 package?

The thermal resistance junction-to-ambient (R_JA) for MC78L15ABPRA in TO-92 package is 200 °C/W, as stated in the Thermal Characteristics table. This value assumes no heatsink and standard PCB mounting. Power dissipation must be limited accordingly - e.g., at 100 mA and 2 V dropout (200 mW), junction temperature rise is 40°C above ambient, keeping total TJ well within the 150°C limit.

Is MC78L15ABPRA RoHS compliant and lead-free?

Yes, MC78L15ABPRA is Pb-free and RoHS compliant, as confirmed in the Ordering Information and Marking Diagrams sections. The "P" suffix in the part number denotes Pb-free TO-92 packaging, and all variants listed (including MC78L15ABPRA) carry the "Pb-Free Package" designation in the datasheet's ordering tables and marking diagrams.