STMicroelectronics L7815ABP

Overview

L7815ABP from STMicroelectronics is a three-terminal positive linear voltage regulator delivering a fixed +15 V output with up to 1.5 A continuous current, thermal overload protection, short-circuit protection, and ±2 % output voltage tolerance (A version) over –40 °C to +125 °C operating junction temperature. It is used in industrial power supplies, embedded control modules, and local on-card regulation where stable mid-rail voltage is required.

For engineers reviewing the L7815ABP datasheet, L7815ABP pinout, L7815ABP application, or L7815ABP equivalent, key selection criteria include dropout voltage (2 V at 1 A), load regulation (≤100 mV), supply voltage rejection (58 dB at 120 Hz), and TO-220FP package thermal resistance (R_thJC = 5 °C/W).

Technical Context

The L7815ABP implements a monolithic series-pass transistor architecture with internal current limiting, safe operating area (SOA) protection, and thermal shutdown circuitry-enabling robust operation without external protection components. Its design targets fixed-voltage local regulation in space-constrained PCBs where input-to-output differential exceeds 2 V.

It operates across an input voltage range of 17.5 V to 30 V for full-load 15 V output, with guaranteed performance over –40 °C to +125 °C junction temperature. Output noise is specified at 10 µV/√Hz (10 Hz–100 kHz), and quiescent current remains stable at 4.4–6 mA under varying line and load conditions.

Key Specifications

Pinout & Package

Package: TO-220FP (3-pin, vertical mounting, isolated tab, plastic body with metal heat sink pad).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM7815CT and MC7815BD2TR4, the L7815ABP uniquely balances extended temperature compliance, TO-220FP mechanical compatibility, and proven field reliability in industrial control environments-making it optimal for upgrades and new designs requiring drop-in qualification.

Availability

L7815ABP is available at Aetrix Electronics and suitable for industrial PLCs, automotive body control units, test equipment power rails, and legacy instrumentation requiring stable component supply and long-term lifecycle support.

Supply support for L7815ABP 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 power management, microcontrollers, and analog ICs for industrial, automotive, and consumer markets.

The L78 series was designed as a family of rugged, pin-compatible fixed-voltage linear regulators targeting cost-sensitive, high-reliability embedded power applications-emphasizing simplicity, thermal resilience, and wide input voltage tolerance.

FAQ

What is the minimum input voltage required for L7815ABP to maintain regulation at full 1.5 A load?

The L7815ABP requires a minimum input voltage of 17.5 V to sustain 15 V output at 1 A (per datasheet Table 8); at 1.5 A, derating applies due to thermal limits. With TO-220FP and typical heatsinking, VI ≥ 19 V is recommended for sustained 1.5 A operation to stay within R_thJA = 60 °C/W thermal limits and avoid thermal shutdown.

Can L7815ABP be used in parallel to increase output current?

No-L7815ABP lacks built-in current-sharing features such as current-limit matching or master-slave control. Parallel connection risks thermal runaway due to parameter mismatches. For >1.5 A, use a single higher-current regulator (e.g., L200 or switching alternative) or redesign with external pass transistors and ballast resistors per ST application note AN105.

Does L7815ABP require input and output capacitors, and what values are validated?

Yes: a minimum 0.33 µF ceramic capacitor is required at the input (within 1 cm of Pin 1) and 0.1 µF ceramic at the output (within 1 cm of Pin 3) to ensure stability and transient response. Larger bulk electrolytics (e.g., 10–100 µF) may be added externally for ripple reduction but do not replace the mandatory ceramics per Figure 4 in DS0422 Rev 38.

How does the L7815ABP's short-circuit protection behave under sustained fault conditions?

Under sustained short-circuit, L7815ABP enters thermal shutdown after junction temperature exceeds ~165 °C, cycling on/off until fault removal. Peak short-circuit current is 2.2 A (non-dissipative pulse), but steady-state fault current is limited to ~0.2 A by internal current limiting-preventing damage while allowing safe detection and system-level fault handling.