onsemi MC79L05ABD

Overview

MC79L05ABD 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), 1.7 V dropout at 40 mA, and thermal shutdown/current limiting protection. It operates across −40°C to +125°C and requires no external components in basic configurations, serving as a compact on-card negative supply for analog signal chains and microcontroller peripherals.

For engineers reviewing the MC79L05ABD datasheet, pinout, applications, or equivalent options, key selection criteria include its SOIC-8 package, −5 V output stability under 100 mA load, input voltage range up to −30 V, ripple rejection of 41–49 dB at 120 Hz, and guaranteed operation across industrial temperature extremes.

Technical Context

The MC79L05ABD implements a monolithic bipolar transistor-based series pass architecture with internal current-limiting circuitry and thermal overload protection. Its regulation relies on a stable bandgap reference and error amplifier driving the pass element, enabling fixed −5 V output without external feedback components.

It features low quiescent current (6.0 mA typical at +25°C), 40 µV RMS output noise (10 Hz–100 kHz), and maintains regulation with input voltages as low as −7.0 V (for −5 V output), requiring only 2.0 V headroom above output during ripple valleys per design guidance.

Key Specifications

Pinout & Package

MC79L05ABD is housed in an SOIC-8 (Case 751) surface-mount package with exposed pad thermal enhancement. Pin 1 = V_OUT, Pin 2 = V_IN, Pin 3 = V_IN, Pin 4 = NC, Pin 5 = GND, Pin 6 = V_IN, Pin 7 = V_IN, Pin 8 = NC - dual-input configuration allows parallel connection of multiple input pins to reduce trace resistance and improve current handling.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM79L05ACM/NOPB and TL79L05ACDR, MC79L05ABD provides verified −40°C to +125°C operation, tighter output tolerance (±4% vs. ±5%), and manufacturer-validated thermal performance in SOIC-8 - making it the preferred choice for ruggedized embedded systems requiring long-term reliability under thermal stress.

Availability

MC79L05ABD is available at Aetrix Electronics and suitable for industrial sensor nodes, automotive body electronics, and medical analog front-ends requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for MC79L05ABD 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 infrastructure markets.

The MC79L00A Series was designed to replace Zener-diode-based negative regulators in cost-sensitive, space-constrained applications - delivering integrated protection and precision in legacy-compatible footprints.

FAQ

What is the maximum input voltage rating for MC79L05ABD?

The MC79L05ABD supports a maximum input voltage of −30 VDC when configured for −5 V output. 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 irreversible damage, as specified in the Absolute Maximum Ratings table of the official ON Semiconductor datasheet.

Does MC79L05ABD require input and output capacitors for stable operation?

MC79L05ABD does not require external capacitors for basic regulation, but ON Semiconductor recommends a 0.33 µF input bypass capacitor (tantalum or low-ESR ceramic) when connected via long traces to the power supply filter, and a 0.1 µF output capacitor to improve transient response. These values are validated in the standard application circuit (Figure 3) and referenced in the Applications Information section.

How many input pins does MC79L05ABD have, and why are there multiple V_IN connections?

MC79L05ABD has four dedicated V_IN pins (pins 2, 3, 6, and 7) in its SOIC-8 package. This multi-pin input structure reduces effective series resistance and distributes current, lowering localized heating and improving thermal performance - especially critical for a 100 mA regulator in a small SOIC-8 footprint without a thermal pad.

Is MC79L05ABD pin-compatible with the TO-92 version MC79L05ABPG?

No, MC79L05ABD (SOIC-8) is not pin-compatible with MC79L05ABPG (TO-92). The SOIC-8 variant uses an 8-pin layout with duplicated V_IN and NC pins, while the TO-92 version is a 3-pin device (GND, Input, Output). PCB redesign and layout changes are required when substituting between these packages - they share electrical functionality but differ mechanically and electrically in pin assignment.

What is the output voltage tolerance of MC79L05ABD over its full operating temperature range?

The MC79L05ABD guarantees an output voltage of −4.8 V to −5.2 V (±4%) at TJ = +25°C. Over the full −40°C to +125°C junction temperature range, the datasheet specifies output voltage as −4.75 V to −5.25 V under defined test conditions (VI = −10 V, IO = 1–40 mA), confirming tight regulation across industrial and automotive thermal profiles.