STMicroelectronics L78L08ABD13TR

Overview

L78L08ABD13TR from STMicroelectronics is a fixed-output +8 V, 100 mA positive linear voltage regulator in SO-8 package with ±4% output tolerance, 1.7 V dropout voltage, thermal overload and short-circuit protection, and no external components required-used for local regulation in industrial control modules, sensor signal conditioning circuits, and low-power microcontroller power rails.

For engineers reviewing the L78L08ABD13TR datasheet, L78L08ABD13TR pinout, L78L08ABD13TR application, or L78L08ABD13TR equivalent, this device serves as a robust, drop-in replacement for Zener/resistor regulators where low quiescent current (6 mA typ.), high PSRR (37–45 dB), and stable 8 V output under load/line variation are critical.

Technical Context

The L78L08ABD13TR implements a monolithic three-terminal linear regulator architecture with internal current limiting, thermal shutdown, and safe-area protection-ensuring fault resilience without external circuitry. Its SO-8 package integrates pins 2, 3, 6, and 7 to the die attach flag for enhanced thermal dissipation (R_thJC = 20 °C/W).

It operates across –40 °C to +125 °C junction temperature range (L78LxxAB grade), supports input voltages up to 35 V at 8–15 V output variants, and delivers regulated 8 V output with ≤80 mV load regulation (1–100 mA) and ≤175 mV line regulation (10.5–23 V input).

Key Specifications

Pinout & Package

SO-8 package with exposed die attach flag connected to pins 2, 3, 6, and 7 for low thermal resistance (R_thJA = 55 °C/W with 6 cm² PCB copper pour). Pin 1 = Input, Pin 2 = Ground, Pin 3 = Output, Pin 4 = Ground, Pin 5 = Ground, Pin 6 = Output, Pin 7 = Output, Pin 8 = Input.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed-output linear regulator applications.

Compared with LM78L08ACZ/NOPB and TL78L08ACDR, the L78L08ABD13TR provides tighter tolerance, wider temperature range, superior thermal design via multi-pin SO-8, and lower noise-making it optimal for ruggedized embedded systems demanding long-term stability.

Availability

L78L08ABD13TR is available at Aetrix Electronics and suitable for industrial sensor interfaces, PLC I/O modules, microcontroller power rails, and low-power timer circuits requiring stable component supply with full lifecycle support.

Supply support for L78L08ABD13TR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, specializing in automotive, industrial, and power management ICs with strong European manufacturing and R&D infrastructure.

The L78L series belongs to ST's legacy linear regulator product line, designed specifically for cost-effective, robust local regulation in space-constrained industrial and consumer electronics where simplicity, reliability, and wide temperature operation are essential.

FAQ

What is the maximum input voltage for L78L08ABD13TR?

The absolute maximum DC input voltage is 35 V when regulating 8 V output, per Table 1 of DS0424 Rev 30. Operation above this risks permanent damage due to internal junction breakdown, even with thermal protection active. For reliable 8 V output, recommended input is 9.7–23 V to maintain ≥1.7 V headroom and minimize power dissipation.

Does L78L08ABD13TR require input/output capacitors?

Yes-ST specifies 0.33 µF ceramic input capacitor (CI) and 0.1 µF ceramic output capacitor (CO) for stability and transient response, as defined in all electrical characteristic test conditions. Omitting either risks oscillation or poor load-step recovery, especially with long PCB traces or high-ESR capacitors.

Can L78L08ABD13TR be used in parallel for higher current?

No-ST does not recommend paralleling L78L08ABD13TR units due to mismatched output voltages (±4% tolerance) causing current hogging and thermal imbalance. Instead, use a single higher-current regulator (e.g., L7808CD2T) or add an external pass transistor per Figure 14 in DS0424 for >100 mA applications.

Is the SO-8 package thermally enhanced compared to TO-92?

Yes-the SO-8 variant uses internal frame modification connecting pins 2, 3, 6, and 7 to the die attach flag, achieving R_thJC = 20 °C/W (vs. 150 °C/W for TO-92) and R_thJA = 55 °C/W with 6 cm² copper pour. This allows full 100 mA output at higher ambient temperatures where TO-92 would thermally throttle.