Texas Instruments LM79L05ACM

Overview

LM79L05ACM from Texas Instruments is a fixed-output, 3-terminal negative voltage regulator delivering −5 V at up to 100 mA, with ±5% output voltage error over load, line, and temperature. It features internal short-circuit, thermal, and safe operating area protection, and is optimized for use in dual-rail analog supplies, industrial control power rails, and low-noise analog subsystems requiring stable negative bias.

For engineers reviewing the LM79L05ACM datasheet, LM79L05ACM pinout, LM79L05ACM application, or LM79L05ACM equivalent, this page provides verified technical context, SOIC-8 package details, real-world application cards, and two validated alternative parts - all grounded in TI's SNOSBR8K revision K datasheet and official packaging addendum.

Technical Context

The LM79L05ACM implements a monolithic bipolar linear regulator architecture with built-in current limiting, thermal shutdown, and SOA protection. Its output is fixed at −5 V and requires only a 0.1 μF output capacitor for stability, achieving 0.07% line regulation and 0.01% load regulation under specified conditions.

It operates across 0°C to +70°C ambient, supports input voltages down to −7.5 V (min) and up to −35 V (abs max), and exhibits 40–120 μV RMS output noise (10 Hz–10 kHz). The device is not adjustable by default but can be externally modified using resistor networks per Figure 2 of the datasheet.

Key Specifications

Pinout & Package

LM79L05ACM is housed in an 8-pin SOIC (D) package (JEDEC MS-012AA), 3.91 mm wide, 4.9 mm long, 1.75 mm max height, RoHS-compliant with Sn lead finish and MSL Level-1 rating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM79L05ACZ/NOPB, the LM79L05ACM offers superior thermal performance in reflow-assembled boards and tighter SOIC layout control; versus LM337LD/NOPB, it trades adjustability for guaranteed −5 V accuracy and simplified bill-of-materials.

Availability

LM79L05ACM is available at Aetrix Electronics and suitable for industrial control power rails, analog sensor signal conditioning, and legacy embedded system retrofits requiring stable component supply and long-term sourcing continuity.

Supply support for LM79L05ACM 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 leader specializing in analog, embedded processing, and high-reliability components for industrial, automotive, and communications markets.

The LM79LXXAC series was designed specifically for cost-sensitive, space-constrained applications needing robust fixed negative regulation - emphasizing thermal efficiency, intrinsic protection, and minimal external components.

FAQ

What is the maximum input voltage for LM79L05ACM?

The absolute maximum input voltage for LM79L05ACM is −35 V, as specified in the SNOSBR8K datasheet Absolute Maximum Ratings table. However, for reliable operation within specifications, the recommended input range is −7.5 V to −20 V. Exceeding −35 V risks permanent damage to the internal pass transistor and protection circuitry. Always observe derating guidelines for thermal safety at elevated ambient temperatures.

Does LM79L05ACM require an input capacitor?

The LM79L05ACM does not mandate an input capacitor for basic stability, but TI strongly recommends a 0.33 μF ceramic capacitor placed close to Pins 5/6/8 (−V_IN) to suppress high-frequency noise and prevent oscillation when sourced from long traces or switching supplies. This is distinct from the required 0.1 μF output capacitor, which is mandatory for loop stability per Figure 1 and datasheet Section 8.2.1.

Can LM79L05ACM be used in parallel for higher current?

No - LM79L05ACM is not designed for direct parallel operation due to mismatched output voltages and lack of current-sharing circuitry. Attempting parallel connection may cause one device to dominate conduction, leading to thermal imbalance and premature failure. For >100 mA requirements, use LM337LD/NOPB or discrete pass transistor augmentation per AN-1112 guidelines.

What is the meaning of 'AC' in LM79L05ACM?

The 'AC' suffix in LM79L05ACM denotes the commercial temperature grade (0°C to +70°C ambient), distinguishing it from military-grade variants (e.g., 'A' alone implies wider temp range). The 'M' indicates the SOIC-8 (D) package per TI's ordering nomenclature. This part is not obsolete - only the LM79L05AC (without 'M') is marked obsolete in the datasheet; LM79L05ACM/NOPB.B remains active per TI's 2025 packaging addendum.

How does LM79L05ACM handle short-circuit conditions?

LM79L05ACM incorporates internal short-circuit current limiting that holds output current near 150 mA during sustained shorts, combined with thermal shutdown that activates at ~125°C junction temperature. Once the fault is removed and junction temperature drops below ~110°C, the device automatically recovers without latch-up or manual reset - enabling robust operation in environments prone to intermittent wiring faults or connector misinsertion.