Texas Instruments MC79L15ACLPME3

Overview

MC79L15ACLPME3 from Texas Instruments is a fixed negative-voltage linear regulator delivering –15 V output at up to 100 mA, with ±5% output voltage tolerance, 1.7 V dropout at 40 mA, and internal thermal-overload and short-circuit protection. It operates across 0°C to 125°C and requires no external components for basic regulation in low-power analog or logic supply rails.

For engineers reviewing the MC79L15ACLPME3 datasheet, MC79L15ACLPME3 pinout, MC79L15ACLPME3 application, or MC79L15ACLPME3 equivalent, key selection criteria include guaranteed –15 V output accuracy over temperature, TO-92 package thermal resistance (140°C/W), ripple rejection of 33–39 dB at 120 Hz, and compatibility with standard 0.33 µF input / 0.1 µF output capacitor configuration.

Technical Context

The MC79L15ACLPME3 implements a monolithic PNP series-pass transistor architecture with built-in current limiting and thermal shutdown circuitry. Its feedback loop maintains regulated output by comparing a scaled version of the output against an internal bandgap reference, enabling stable operation without external compensation.

It accepts input voltages from –17.5 V to –30 V, supports load currents up to 100 mA, and exhibits 75 mV output regulation variation over 1–40 mA load range at 25°C. Bias current remains stable at 6.5 mA (25°C) and 6 mA (125°C), with ≤1.5 mA variation across full input voltage and temperature ranges.

Key Specifications

Pinout & Package

MC79L15ACLPME3 uses the TO-92 (LP) plastic cylindrical package - a 3-pin through-hole device with straight or formed leads, compliant with JEDEC TO-226 Variation AA. Package outline and lead dimensions conform to TI mechanical drawing MSOT002A.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC79L15ACLPR and LM7915ACZ, the MC79L15ACLPME3 offers optimized cost and footprint for <100 mA applications in through-hole or manual assembly contexts, while maintaining identical regulation performance and protection features within its specified operating envelope.

Availability

MC79L15ACLPME3 is available at Aetrix Electronics and suitable for industrial sensor interfaces, legacy serial communication modules, and embedded analog subsystems requiring stable component supply and long-term obsolescence management.

Supply support for MC79L15ACLPME3 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

Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, specializing in analog, embedded processing, and logic technologies for industrial, automotive, and communications markets.

The MC79L00 series was designed specifically for low-power, cost-sensitive negative-voltage regulation in space-constrained applications - emphasizing simplicity, reliability, and direct compatibility with legacy discrete regulator designs.

FAQ

What is the maximum input voltage rating for MC79L15ACLPME3?

The MC79L15ACLPME3 has an absolute maximum input voltage rating of –35 V. This applies across the full operating temperature range and is specified for MC79L12 and MC79L15 variants. Exceeding this voltage risks permanent damage, even if other parameters remain within limits. The recommended operating range is –17.5 V to –30 V for optimal regulation and thermal performance.

Does MC79L15ACLPME3 require external capacitors to operate stably?

Yes, the MC79L15ACLPME3 requires a 0.33 µF capacitor on the input and a 0.1 µF capacitor on the output for stable operation. These values are specified in the datasheet's test conditions and are necessary to maintain phase margin, suppress high-frequency oscillation, and ensure proper transient response. Omitting either capacitor may result in output instability or excessive noise.

What is the thermal resistance (θ_JA) of MC79L15ACLPME3 in its TO-92 package?

The MC79L15ACLPME3 has a junction-to-ambient thermal resistance (θ_JA) of 140°C/W in the LP (TO-92) package. This value assumes standard PCB mounting with no copper pour or heatsinking. At 25°C ambient and 100 mA load with –30 V input, power dissipation reaches ~1.5 W, resulting in a theoretical junction temperature rise of 210°C - exceeding the 150°C limit. Derating or heatsinking is essential for continuous operation near maximum ratings.

Is MC79L15ACLPME3 pin-compatible with older MC79L15 variants?

Yes, the MC79L15ACLPME3 is pin-compatible with all MC79L15 family members in the same LP (TO-92) package, including MC79L15ACLP and MC79L15ACLPR. Pin 1 is INPUT, Pin 2 is COMMON, and Pin 3 is OUTPUT - matching the standard TO-92 pinout for negative regulators. No PCB changes are required when substituting within the same package variant.

What output voltage tolerance does MC79L15ACLPME3 guarantee over temperature?

The MC79L15ACLPME3 guarantees an output voltage tolerance of ±5% over the full operating junction temperature range of 0°C to 125°C. At 25°C, the typical output is –15 V, with minimum –14.25 V and maximum –15.75 V. This specification is verified under load conditions of 1–40 mA and input voltage of –23 V, ensuring predictable performance in thermally demanding environments.