Texas Instruments LM79L05ACTLX/NOPB

Overview

LM79L05ACTLX/NOPB from Texas Instruments is a fixed-output, 3-terminal negative linear voltage regulator delivering −5 V at up to 100 mA, with ±5% output voltage accuracy over load, line, and temperature. It features internal short-circuit, thermal, and safe operating area protection, and is optimized for low-noise, stable operation with only a 0.1 μF output capacitor in DSBGA packaging for space-constrained PCBs.

For engineers reviewing the LM79L05ACTLX/NOPB datasheet, LM79L05ACTLX/NOPB pinout, LM79L05ACTLX/NOPB application, or LM79L05ACTLX/NOPB equivalent, key selection criteria include its −5 V fixed output, DSBGA-6 package footprint, 0.01% load regulation, 0.07% line regulation, and compatibility with dual-rail ±5 V/±15 V power supplies in industrial and embedded analog subsystems.

Technical Context

The LM79L05ACTLX/NOPB implements a monolithic PNP pass transistor architecture with built-in current limiting, thermal shutdown, and SOA protection-enabling robust operation without external compensation. Its design targets low-quiescent-current (2–6 mA) regulation under varying input conditions (−7.3 V to −20 V), with ripple rejection of 50 dB at 120 Hz and output noise of 40–120 μV RMS (10 Hz–10 kHz).

It operates across 0°C to +70°C ambient, supports stable regulation with minimal external capacitance, and is specified for use in fixed-voltage configurations-though external resistors allow adjustable outputs per AN-1112. The DSBGA-6 package enables high-density layout while maintaining thermal performance via solder-bump thermal path.

Key Specifications

Pinout & Package

LM79L05ACTLX/NOPB uses a 6-bump DSBGA (YZR) package measuring 1.09 mm × 1.88 mm × 0.76 mm (height), with solder bumps on bottom for direct PCB interconnect and thermal conduction. Pin 1 orientation is quadrant Q1 per tape-and-reel specification.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM79L05ACZ/NOPB and LM79L05ACM/NOPB, the LM79L05ACTLX/NOPB delivers identical regulation performance in the smallest footprint (1.09 mm × 1.88 mm), enabling ultra-compact dual-rail power delivery-but requires fine-pitch SMT assembly and careful thermal pad design for optimal junction temperature control.

Availability

LM79L05ACTLX/NOPB is available at Aetrix Electronics and suitable for industrial sensor conditioning, embedded analog front-ends, and test equipment bias rails requiring stable component supply, long-term lifecycle support, and RoHS-compliant DSBGA packaging.

Supply support for LM79L05ACTLX/NOPB 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 power management technologies, with decades of expertise in precision linear regulators and industrial-grade ICs.

The LM79LXXAC series was designed specifically for cost-sensitive, space-constrained industrial and embedded systems requiring reliable fixed negative voltage regulation with minimal external components and robust fault protection.

FAQ

What is the maximum input voltage rating for LM79L05ACTLX/NOPB?

The absolute maximum input voltage for LM79L05ACTLX/NOPB is −35 V. Operation beyond this risks permanent damage. For reliable regulation, input must remain between −7.3 V and −20 V per datasheet specifications. Exceeding −20 V increases dropout stress and reduces thermal margin, especially at full 100 mA load. Always verify input transient suppression in your design to prevent violation of this limit during power-up or fault conditions. LM79L05ACTLX/NOPB includes internal protection but is not rated for sustained overvoltage.

Does LM79L05ACTLX/NOPB require an input capacitor?

While not strictly mandatory, TI recommends a 0.33 μF ceramic input capacitor placed close to the LM79L05ACTLX/NOPB input pin to suppress high-frequency noise and improve transient response-especially when the regulator is located >2 inches from the bulk filter capacitor. This capacitor stabilizes the input impedance seen by the regulator and prevents oscillation under dynamic load changes. LM79L05ACTLX/NOPB remains functional without it in low-noise, low-dI/dt environments, but inclusion is considered best practice for industrial reliability.

Can LM79L05ACTLX/NOPB be used in adjustable configurations?

Yes, LM79L05ACTLX/NOPB can be configured for adjustable negative output voltages using external resistors per Figure 2 in the datasheet, though it is optimized for fixed −5 V operation. The adjustment equation is −V_OUT = −5 V − (5 V/R₁ + I_Q)·R₂, with constraint 5 V/R₁ > 3·I_Q. However, accuracy and regulation degrade compared to fixed mode due to quiescent current variation and resistor tolerance. For wide-range adjustability, TI recommends the LM137L series instead. LM79L05ACTLX/NOPB retains all internal protections in adjustable mode.

What is the thermal resistance (θ_JA) of LM79L05ACTLX/NOPB?

The published θ_JA for LM79L05ACTLX/NOPB in its DSBGA-6 (YZR) package is 114°C/W when mounted on a 4-layer JEDEC-standard test board (JESD 51-7). Actual thermal performance depends heavily on PCB layout: thermal vias under the ground bumps, copper pour area, and layer stack-up significantly impact real-world θ_JA. With proper thermal design (≥4 thermal vias, 200 mm² copper), θ_JA can improve to ~65°C/W. Junction temperature must stay below +125°C; at 100 mA and −15 V input, power dissipation is ~1 W, requiring careful thermal validation. LM79L05ACTLX/NOPB includes thermal shutdown to prevent damage if limits are exceeded.

Is LM79L05ACTLX/NOPB pin-compatible with other LM79LXX variants?

No-LM79L05ACTLX/NOPB is not pin-compatible with LM79L12AC or LM79L15AC variants, even within the same DSBGA-6 package. While all share identical bump layout and mechanical footprint, their internal voltage-setting networks are trimmed for −5 V, −12 V, or −15 V outputs respectively. Substituting one for another will result in incorrect output voltage and potential system malfunction. Each variant has unique part marking (e.g., "P B" for LM79L05ACTLX/NOPB) and distinct electrical test limits. Always match the exact part number to the required output voltage; LM79L05ACTLX/NOPB is validated only for −5 V operation.