STMicroelectronics L7915CV

Overview

L7915CV from STMicroelectronics is a three-terminal fixed negative voltage regulator delivering -15 V output at up to 1.5 A, featuring thermal overload protection, short-circuit protection, and SOA-safe output transition. It operates with input voltages down to -35 V (for VO = -15 V), supports local on-card regulation, and is widely used in split ±15 V power supplies for op-amp circuits and analog instrumentation.

For engineers reviewing the L7915CV datasheet, L7915CV pinout, L7915CV application, or L7915CV equivalent, key selection criteria include guaranteed -15 V output tolerance (±3.3% at 25°C), dropout voltage of 1.1 V at 1 A, thermal resistance (RthJC = 5 °C/W in TO-220), and compatibility with standard L78xx positive regulators in dual-rail designs.

Technical Context

The L7915CV implements a monolithic PNP pass transistor-based linear regulation architecture with internal current limiting, thermal shutdown, and safe-area protection. Its feedback loop maintains stable -15 V output across load currents from -5 mA to -1.5 A and input variations from -18.5 V to -30 V.

Designed for fixed-output operation without external components, it accepts solid tantalum input/output capacitors (CI = 2.2 µF, CO = 1 µF) for stability and includes built-in supply voltage rejection (54–60 dB at 120 Hz) and low output noise (250 µV RMS, 10 Hz–100 kHz).

Key Specifications

Pinout & Package

Supplied in TO-220 package (standard single-gauge frame), with metal tab electrically connected to the Output terminal and suitable for direct heatsink mounting.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM7915CT and MC7915BT, the L7915CV delivers tighter output voltage accuracy, lower noise, superior thermal performance, and integrated SOA protection - making it the preferred choice for new designs demanding reliability and analog integrity.

Availability

L7915CV is available at Aetrix Electronics and suitable for industrial control systems, test equipment, and audio electronics requiring stable component supply, long-lifecycle support, and consistent parametric performance across production batches.

Supply support for L7915CV 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 microcontrollers, power management ICs, sensors, and analog devices for industrial, automotive, and consumer markets.

The L79xxC series belongs to ST's legacy linear regulator product line, engineered specifically for robust, low-cost, fixed-output negative rail generation in dual-supply analog and mixed-signal systems.

FAQ

What is the maximum input voltage for L7915CV?

The absolute maximum DC input voltage is -35 V when regulating -15 V output, as specified in Table 2 of the datasheet. Operation above this risks permanent device failure due to junction breakdown. For reliable long-term use, ST recommends limiting VI to ≤ -30 V under worst-case thermal conditions.

Can L7915CV be used in adjustable configurations?

Yes - though optimized for fixed -15 V operation, the L7915CV can be configured as an adjustable regulator using external resistors (per Figure 6 in the datasheet), enabling output voltages more negative than -15 V. However, stability and regulation accuracy depend on proper compensation and capacitor selection.

Is a heatsink required for 1.5 A operation?

Yes - at 1.5 A with a 15 V input-to-output differential (e.g., VI = -30 V), power dissipation exceeds 22 W. With RthJC = 5 °C/W and typical RthCA ≈ 40 °C/W, junction temperature would exceed 150°C without a heatsink. A minimum 10°C/W heatsink is recommended for full-load continuous operation.

Does L7915CV require input and output capacitors?

Yes - a minimum 2.2 µF solid tantalum capacitor at the input (CI) and 1 µF at the output (CO) are mandatory for stability, as stated in Section 6 of the datasheet. Aluminum electrolytic capacitors may be substituted only if capacitance is increased ≥10×, and a reverse-protection diode (e.g., 1N4001) is added for transient safety.