STMicroelectronics L7815CD2T-TR

Overview

L7815CD2T-TR from STMicroelectronics is a three-terminal positive linear voltage regulator delivering a fixed +15 V output with up to 1.5 A continuous current, featuring thermal overload protection, short-circuit protection, and safe operating area (SOA) protection. It uses the D²PAK (TO-263) surface-mount package and operates across -40 °C to 125 °C junction temperature, supporting local on-card regulation in industrial power supplies and embedded control systems.

For engineers reviewing the L7815CD2T-TR datasheet, L7815CD2T-TR pinout, L7815CD2T-TR application, or L7815CD2T-TR equivalent, key selection criteria include dropout voltage (2 V at 1 A), load regulation (≤300 mV over 5 mA–1.5 A), supply voltage rejection (58 dB at 120 Hz), output voltage tolerance (±3% over full temperature/load range), and thermal resistance (3 °C/W junction-to-case).

Technical Context

This IC implements a monolithic series-pass linear regulator architecture with internal current limiting, thermal shutdown, and SOA protection-no external components required for basic operation. Its feedback loop maintains stable +15 V output despite input variations from 17.5 V to 30 V and load changes from 5 mA to 1.5 A.

The device operates in continuous conduction mode with fixed internal reference and error amplifier, delivering low-noise regulation (10 µV/√Hz output noise density) and minimal line/load interaction due to dedicated compensation. Junction temperature monitoring enables automatic shutdown before thermal damage occurs.

Key Specifications

Pinout & Package

D²PAK (TO-263) thermally enhanced surface-mount package with exposed metal tab for heatsinking; 3-pin configuration (Input, Ground, Output) in standard outline per DS0422 Rev 38.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM7815CD2T and MC7815CD2TG, the L7815CD2T-TR offers superior supply voltage rejection (58 dB vs. ≤55 dB) and lower output noise (10 µV/√Hz vs. ≥40 µV/√Hz), making it preferred for precision analog applications where input ripple and thermal drift are critical.

Availability

L7815CD2T-TR is available at Aetrix Electronics and suitable for industrial PLC power supplies, automotive body control modules, test equipment front-end supplies, and medical diagnostic sensor interfaces requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for L7815CD2T-TR 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, Switzerland, designing and manufacturing silicon solutions for automotive, industrial, and consumer markets since 1987.

The L78 series belongs to ST's legacy linear regulator product line, engineered specifically for robust, low-cost, fixed-voltage local regulation in space-constrained and thermally demanding applications - emphasizing reliability over programmability.

FAQ

What is the minimum input voltage required for regulation with L7815CD2T-TR?

The minimum input voltage is 17.5 V DC, derived from the 2 V dropout specification plus the 15 V nominal output. Operation below this threshold results in unregulated output voltage collapse. Input must remain ≥17.5 V across all load and temperature conditions to maintain regulation.

Does L7815CD2T-TR require external capacitors, and what values are recommended?

Yes: a minimum 0.33 µF ceramic capacitor is required at the input pin (close to the device), and a minimum 0.1 µF ceramic capacitor at the output pin. These stabilize the internal feedback loop and prevent oscillation. Larger values (e.g., 10 µF tantalum at output) improve transient response but are not mandatory for basic functionality.

How does thermal performance differ between D²PAK and TO-220 packages for this regulator?

The D²PAK (L7815CD2T-TR) has R_thJC = 3 °C/W, while TO-220 variants have R_thJC = 5 °C/W. This 40% lower junction-to-case resistance allows the D²PAK to dissipate more power into an external heatsink - critical for sustained 1.5 A operation at elevated ambient temperatures.

Can L7815CD2T-TR be used in parallel to increase output current?

No - the L7815CD2T-TR lacks built-in current-sharing features such as current-limit matching or master-slave control. Parallel connection risks thermal runaway due to parameter mismatch. For >1.5 A, use a single higher-current regulator or switch-mode solution instead.