onsemi MC79L15ABP

Overview

MC79L15ABP from ON Semiconductor is a three-terminal, fixed-output −15 V negative voltage regulator delivering up to 100 mA, featuring internal thermal shutdown and short-circuit current limiting in a TO-92 package. It operates across −40°C to +125°C, requires no external components for basic operation, and maintains ±4% output voltage tolerance at 25°C - ideal for on-card biasing of op-amps and analog signal chains in industrial control modules.

For engineers reviewing the MC79L15ABP datasheet, pinout, applications, or equivalent options, key selection criteria include its guaranteed −14.4 V to −15.6 V output over temperature and load, 1.7 V dropout at 40 mA, 300 mV input regulation (−17.5 V to −30 V), and compatibility with standard 0.33 µF input / 0.1 µF output capacitor configuration.

Technical Context

The MC79L15ABP implements a monolithic bipolar linear regulator architecture with built-in current-limiting and thermal-foldback protection. Its internal reference and error amplifier maintain regulation without external feedback components, and its dropout behavior remains stable down to 1.7 V differential between input and output under nominal 40 mA load.

Designed for low-noise analog subsystems, it delivers 90 µV RMS output noise (10 Hz–100 kHz) and 34 dB ripple rejection at 120 Hz with −18.5 V to −28.5 V input range. Input bias current stays below 6.5 mA at 25°C and drops only marginally at 125°C, ensuring predictable quiescent power draw in wide-temperature deployments.

Key Specifications

Pinout & Package

MC79L15ABP uses the industry-standard TO-92 plastic package (Case 29), with straight leads and Pb-free finish. Pin assignment follows the universal three-terminal linear regulator convention: Pin 1 = Ground, Pin 2 = Input (−Vin), Pin 3 = Output (−Vout).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar negative voltage regulation applications.

Compared with MC79L15ACPG and LM7915ACZ, the MC79L15ABP uniquely balances extended temperature capability, compact TO-92 footprint, and RoHS compliance - making it optimal for space-constrained industrial designs requiring guaranteed −40°C startup and stable −15 V bias without heatsinking.

Availability

MC79L15ABP is available at Aetrix Electronics and suitable for industrial sensor signal conditioning, legacy analog instrumentation, audio preamp biasing, and embedded control board auxiliary rail applications requiring stable component supply and long-term manufacturability.

Supply support for MC79L15ABP 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

ON Semiconductor (now onsemi) is a global semiconductor supplier specializing in energy-efficient power management, analog, and sensor technologies for automotive, industrial, and cloud infrastructure markets.

The MC79L00A Series was designed specifically to replace inefficient resistor/Zener diode negative regulators in cost-sensitive, low-power analog systems - emphasizing ruggedness, simplicity, and wide-temperature reliability without external components.

FAQ

What is the maximum input voltage rating for the MC79L15ABP?

The MC79L15ABP has an absolute maximum input voltage rating of −30 Vdc for the −15 V version. This rating applies at TA = +25°C and assumes proper thermal management. Exceeding −30 Vdc risks permanent damage due to junction breakdown, even if thermal shutdown activates. Always maintain at least 2 V headroom above the −15 V output to ensure stable regulation under ripple conditions.

Does the MC79L15ABP require input and output capacitors to operate?

The MC79L15ABP can operate without external capacitors in basic low-noise, low-ripple environments. However, ON Semiconductor recommends a 0.33 µF input capacitor (tantalum or ceramic) placed directly across Pins 2 and 1, and a 0.1 µF output capacitor (ceramic) across Pins 3 and 1. These capacitors improve stability, transient response, and ripple rejection - especially when using long input traces or driving capacitive loads. The MC79L15ABP datasheet confirms stable operation with this configuration.

What is the output voltage tolerance of the MC79L15ABP over temperature and load?

The MC79L15ABP guarantees an output voltage of −14.4 V to −15.6 V (±4%) over the full operating temperature range of −40°C to +125°C and load current range of 1.0 mA to 40 mA. At 25°C and 40 mA, typical output is −15.0 V. This tolerance includes effects of line regulation (≤300 mV), load regulation (≤150 mV), and temperature drift - all verified per the official MC79L00A Series datasheet Rev. 10.

Can the MC79L15ABP be used in place of the older MC79L15ACP?

Yes, the MC79L15ABP is a direct functional and pinout replacement for the obsolete MC79L15ACP. Both use the TO-92 package with identical pin assignments (Pin 1 = GND, Pin 2 = Input, Pin 3 = Output) and deliver −15 V output. The MC79L15ABP improves upon the legacy part with extended −40°C to +125°C temperature rating, Pb-free construction, and updated thermal protection circuitry - all while maintaining backward compatibility in existing designs.

How does thermal shutdown work in the MC79L15ABP?

The MC79L15ABP incorporates a monolithic thermal foldback circuit that disables the output stage when junction temperature exceeds +150°C. Once triggered, regulation ceases until the die cools below the hysteresis threshold (~135°C), at which point normal operation resumes automatically. This protection is independent of load current or input voltage and is fully integrated - no external components are needed. The feature is documented in the Absolute Maximum Ratings and Applications Information sections of the MC79L15ABP datasheet.