onsemi MC79L05ABPRA

Overview

MC79L05ABPRA from ON Semiconductor is a 100 mA negative fixed-voltage linear regulator delivering −5.0 V output with ±4% tolerance (−4.8 V to −5.2 V), thermal shutdown, and internal current limiting. It operates over −40°C to +125°C, requires no external components in basic configurations, and is used for on-card negative rail generation in analog front-ends, sensor signal conditioning, and dual-supply op-amp circuits.

For engineers reviewing the MC79L05ABPRA datasheet, pinout, applications, or equivalent options, key selection criteria include dropout voltage (1.7 V at 40 mA), ripple rejection (41–49 dB at 120 Hz), input voltage range (−30 V max), output noise (40 µV RMS), and TO-92 package compatibility with legacy through-hole designs.

Technical Context

The MC79L05ABPRA implements a monolithic bipolar linear regulator architecture with built-in short-circuit current limiting and thermal overload protection. Its internal circuitry maintains regulation across load currents from 1.0 mA to 100 mA and input voltages from −7.0 V to −30 V, with dropout defined as the input-output differential where output deviates by 2%.

It features a fixed −5.0 V reference derived from bandgap and error amplifier stages, with bias current stable at ≤6.0 mA (TJ = +25°C) and ≤5.5 mA (TJ = +125°C). Input bypassing with ≥0.33 µF and output decoupling with ≥0.1 µF are recommended for stability under high-frequency transients or long trace conditions.

Key Specifications

Pinout & Package

MC79L05ABPRA is supplied in the TO-92 (Case 29) plastic package - a 3-lead through-hole format with bent leads, standardized for manual assembly and prototyping. Thermal resistance is 160°C/W (junction-to-ambient, TA = 25°C), requiring minimal heatsinking below ~150 mW dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC79L05ACPRAG and LM79L05ACZ, the MC79L05ABPRA delivers superior thermal robustness (−40°C start-up), lower dropout (1.7 V), and higher ripple rejection (up to 49 dB), making it the preferred choice for mission-critical analog subsystems where reliability across extreme temperatures and noisy input sources is mandatory.

Availability

MC79L05ABPRA is available at Aetrix Electronics and suitable for industrial sensor interfaces, audio signal chains, dual-rail microcontroller peripherals, and legacy backplane power repair requiring stable component supply and long-term lifecycle continuity.

Supply support for MC79L05ABPRA 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, sensors, and connectivity solutions for automotive, industrial, and cloud power applications.

The MC79L00A Series was designed to provide rugged, low-cost, fixed negative voltage regulation for cost-sensitive and space-constrained embedded systems-emphasizing simplicity, reliability, and broad temperature operation without external components.

FAQ

What is the maximum input voltage rating for MC79L05ABPRA?

The MC79L05ABPRA has a maximum input voltage rating of −30 V DC for the −5 V version. This rating applies at TA = +25°C and is derated at higher ambient temperatures per the device's thermal resistance characteristics. Exceeding −30 V may cause permanent damage due to junction breakdown or thermal runaway, even with current limiting active.

Does MC79L05ABPRA require input and output capacitors for stable operation?

MC79L05ABPRA does not require external capacitors for basic regulation, but ON Semiconductor recommends a 0.33 µF input bypass capacitor and a 0.1 µF output decoupling capacitor. These improve transient response, suppress high-frequency noise, and ensure stability-especially when input traces exceed 2 inches or output capacitance exceeds 10 µF.

What is the dropout voltage specification for MC79L05ABPRA, and how is it measured?

The dropout voltage for MC79L05ABPRA is specified as 1.7 V at IO = 40 mA and TJ = +25°C. It is defined as the minimum input-output differential voltage required to maintain output regulation within 2% of nominal (−4.9 V to −5.1 V). Dropout increases slightly at higher load currents and elevated temperatures, as shown in Figure 4 of the datasheet.

Can MC79L05ABPRA be used in automotive applications?

Yes-MC79L05ABPRA is qualified for the automotive temperature range (−40°C to +125°C) and includes enhanced test screening per AEC-Q100 stress requirements for select variants. While MC79L05ABPRA itself is not AEC-Q100 certified, its AB-grade temperature rating and thermal protection make it suitable for non-safety-critical automotive subsystems such as infotainment power rails and body control module analog sections.

How does the thermal shutdown feature operate in MC79L05ABPRA?

The thermal shutdown circuit in MC79L05ABPRA disables the output stage when the silicon junction temperature reaches approximately +150°C. The device remains latched off until the junction cools by ~15°C, then automatically resumes regulation. This behavior is fully internal-no external components or reset signals are needed-and protects against sustained overload or inadequate heatsinking.