onsemi MC79L12ACPRP

Overview

MC79L12ACPRP from ON Semiconductor is a 100 mA negative fixed-voltage linear regulator delivering −12 V output with ±5% tolerance (−11.4 V to −12.6 V), 1.7 V dropout at 40 mA, and thermal shutdown/current limiting protection. It operates across 0°C to +125°C junction temperature and is commonly used for local regulation in analog signal chains, sensor biasing, and dual-supply op-amp circuits.

For engineers reviewing the MC79L12ACPRP datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed −12 V output stability under 100 mA load, TO-92 package thermal performance (R_JA = 160°C/W), input voltage range (−14.5 V to −27 V), ripple rejection (37–42 dB), and low-noise operation (80 µV_RMS).

Technical Context

The MC79L12ACPRP implements a monolithic PNP pass transistor architecture with internal current-limiting and thermal overload protection. Its feedback loop maintains regulation without external components, relying on internal bandgap reference and error amplifier.

It requires no output capacitor for basic stability but benefits from 0.1 µF ceramic output and 0.33 µF input bypass capacitors-especially with long trace lengths or high-capacitive loads-to suppress noise and improve transient response.

Key Specifications

Pinout & Package

MC79L12ACPRP uses the TO-92 (Case 29) through-hole package with bent leads and tape-and-reel shipping (PRP suffix). The package has 3 terminals and a typical thermal resistance of R_JA = 160°C/W at T_A = 25°C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM7912ACZ and MC79M12ACD2G, the MC79L12ACPRP provides optimal cost and simplicity for ≤100 mA TO-92 applications, trading off current capacity and thermal performance for minimal footprint and zero external components.

Availability

MC79L12ACPRP is available at Aetrix Electronics and suitable for industrial sensor conditioning, audio pre-amplifier biasing, dual-supply op-amp circuits, and legacy control board replacements requiring stable component supply and long-term manufacturability.

Supply support for MC79L12ACPRP 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 is a global semiconductor manufacturer specializing in power management, analog, sensor, and logic devices for automotive, industrial, and cloud power applications.

The MC79L00A Series was designed to deliver low-cost, robust negative voltage regulation for cost-sensitive, low-power analog and mixed-signal systems-emphasizing simplicity, reliability, and wide temperature operation.

FAQ

What is the maximum input voltage for MC79L12ACPRP?

The MC79L12ACPRP supports a maximum input voltage of −27 V under specified test conditions (−14.5 V ≤ V_I ≤ −27 V). Exceeding −27 V risks permanent damage, as absolute maximum rating is −35 V for −12 V variants. Always maintain ≥1.7 V differential between input and output to ensure regulation.

Does MC79L12ACPRP require input and output capacitors?

MC79L12ACPRP does not require external capacitors for basic regulation, but ON Semiconductor recommends a 0.33 µF input capacitor (tantalum or ceramic) and 0.1 µF output capacitor (ceramic) to ensure stability, especially with long traces or capacitive loads. These capacitors reduce noise and improve transient response in real-world layouts.

What is the operating temperature range of MC79L12ACPRP?

The MC79L12ACPRP is rated for a junction temperature range of 0°C to +125°C, corresponding to the "C" grade in the part numbering scheme. This makes it suitable for commercial and industrial environments but not extended automotive (−40°C to +125°C) applications-those require the "AB" variant (e.g., MC79L12ABPRAG).

How does thermal protection work in MC79L12ACPRP?

MC79L12ACPRP incorporates internal thermal shutdown that activates at approximately +150°C junction temperature. When triggered, the output is disabled until junction temperature falls below the hysteresis threshold (~135°C), allowing safe automatic recovery without external intervention or latch-up risk.

Is MC79L12ACPRP pin-compatible with other TO-92 negative regulators?

MC79L12ACPRP uses the standard TO-92 pinout: Pin 1 = Ground, Pin 2 = Input, Pin 3 = Output. It is pin-compatible with other MC79LxxAC/AB variants (e.g., MC79L05ACPRP, MC79L15ACPRP) and functionally similar TO-92 negative regulators like LM7912ACZ-but note LM7912ACZ uses reversed pinout (Pin 1 = Output, Pin 2 = Ground, Pin 3 = Input), so direct substitution requires PCB modification.