STMicroelectronics L7815CV

Overview

L7815CV 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 SOA safeguard. It operates with input voltages up to 35 V (for 15 V output), exhibits ±2 % output tolerance (C-grade), and supports industrial temperature range (0 °C to 125 °C). It is used for local on-card regulation in power supplies for microcontroller-based instrumentation and industrial control modules.

For engineers reviewing the L7815CV datasheet, L7815CV pinout, L7815CV application, or L7815CV equivalent, key selection criteria include dropout voltage (2 V at 1 A), load regulation (≤100 mV over 5 mA–1.5 A), supply voltage rejection (58 dB at 120 Hz), quiescent current (4.4–6 mA), and thermal resistance (R_thJA = 50 °C/W in TO-220).

Technical Context

The L7815CV implements a monolithic silicon voltage regulator architecture with internal current limiting, thermal shutdown, and safe operating area (SOA) protection-enabling robust operation without external components under fault conditions. Its feedback loop maintains regulation across line (VI = 17.5–30 V) and load (IO = 5 mA–1.5 A) variations while sustaining stable output despite junction temperature shifts (−1 mV/°C drift).

Designed for fixed-output use, it requires only two external capacitors (CI = 0.33 µF, CO = 0.1 µF) for stability and ripple suppression. The device does not support adjustable output without external resistive networks and lacks enable/disable or power-good signaling functionality.

Key Specifications

Pinout & Package

Supplied in TO-220 package (3-pin, vertical mounting, metal tab connected to GND), with standardized pinout: Pin 1 = Input, Pin 2 = Ground, Pin 3 = Output. The metal tab serves as thermal path and electrical ground connection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM7815CT and MC7815CD2TR4G, the L7815CV offers superior thermal performance in TO-220 (50 °C/W), tighter initial tolerance consistency, and higher supply rejection-making it preferred for thermally constrained or noise-critical 15 V analog rails.

Availability

L7815CV is available at Aetrix Electronics and suitable for industrial control panels, test equipment power subsystems, and sensor signal conditioning circuits requiring stable component supply and long-term lifecycle continuity.

Supply support for L7815CV 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 belongs to ST's legacy linear regulator product line, engineered specifically for cost-sensitive, high-reliability fixed-voltage applications in industrial and instrumentation systems where simplicity, ruggedness, and proven field performance are prioritized.

FAQ

What is the minimum input voltage required for stable 15 V output at 1.5 A?

The L7815CV requires a minimum input voltage of 17.5 V to maintain regulation at full 1.5 A load and 25 °C junction temperature, based on its 2 V dropout specification. At elevated temperatures or higher current, headroom should be increased to 18–19 V to ensure margin against thermal derating and line sag.

Can L7815CV be used in parallel to increase output current?

No-L7815CV is not designed for parallel operation. Its output voltage tolerance (±2 %) and lack of current-sharing control cause unequal load distribution, risking thermal runaway in one device. For >1.5 A, use a single higher-current regulator or a switching pre-regulator followed by L7815CV for noise filtering.

Is a heat sink mandatory for 1 A continuous operation?

Yes-a heat sink is required for reliable 1 A operation at ambient temperatures above 45 °C. With R_thJA = 50 °C/W and 2 V dropout (2 W dissipation), junction temperature rises ~100 °C above ambient. Without heatsinking, T_J exceeds 125 °C at ambient >25 °C, triggering thermal shutdown.

Does L7815CV require both input and output capacitors, and what values are recommended?

Yes-ST specifies a 0.33 µF ceramic capacitor on the input and 0.1 µF ceramic capacitor on the output, placed as close as possible to their respective pins. These prevent oscillation and improve transient response; omitting either risks instability, especially with long input traces or capacitive loads exceeding 100 µF.