STMicroelectronics L7905CV-DG

Overview

L7905CV-DG from STMicroelectronics is a fixed-output, three-terminal negative voltage regulator delivering -5 V at up to 1.5 A, featuring thermal overload protection, short-circuit protection, and SOA-limited output transition. It operates with input voltages down to -35 V (for -5 V output), exhibits ±50 mV load regulation (250–750 mA), and maintains 54–60 dB supply voltage rejection at 120 Hz - widely deployed in split-rail analog power supplies for op-amp biasing and dual-supply instrumentation.

For engineers reviewing the L7905CV-DG datasheet, L7905CV-DG pinout, L7905CV-DG application, or L7905CV-DG equivalent, this device is selected for local negative rail regulation where stable -5 V, robust fault protection, low quiescent current (3 mA), and TO-220FP package thermal performance (R_thJC = 5 °C/W) are required in industrial control and audio signal conditioning circuits.

Technical Context

The L7905CV-DG implements a monolithic PNP pass transistor architecture with internal current limiting, thermal shutdown, and safe operating area (SOA) protection - enabling reliable operation under sustained overload or transient short-circuit conditions. Its feedback loop stabilizes output voltage across line (VI = -8 to -20 V) and load (IO = -5 mA to -1.5 A) variations while maintaining <100 mV total regulation error.

Designed for fixed-voltage operation, it supports external configuration for adjustable outputs or high-current parallel use (e.g., with external pass transistors). The TO-220FP package provides mechanical compatibility with standard heatsinks and meets ECOPACK® environmental compliance requirements without lead-free exemptions.

Key Specifications

Pinout & Package

Supplied in TO-220FP (Full-Pak) package: thermally enhanced variant of TO-220 with insulated tab, 3-pin vertical mounting, and integrated heatsink interface. Pin 1 = Input, Pin 2 = Ground, Pin 3 = Output - pinout matches industry-standard negative regulator layout for drop-in replacement in legacy designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM7905CT and MC7905BT, the L7905CV-DG offers superior thermal performance (R_thJC = 5 °C/W), lower noise (100 µV vs. ≥200 µV), integrated SOA protection, and full ECOPACK® compliance - making it the preferred choice for new industrial and audio designs requiring reliability, efficiency, and regulatory adherence.

Availability

L7905CV-DG is available at Aetrix Electronics and suitable for industrial PLC analog I/O modules, audio power amplifier biasing, and dual-supply op-amp circuits requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for L7905CV-DG 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, analog devices, and MEMS sensors for industrial, automotive, and consumer markets.

The L79xxC series was developed specifically for robust, cost-effective local negative voltage regulation in split-rail systems - targeting applications where reliability, thermal resilience, and compatibility with legacy L78xx positive regulators are essential.

FAQ

What is the maximum input voltage rating for L7905CV-DG?

The absolute maximum DC input voltage is -35 V when regulating -5 V output. Exceeding this risks permanent damage due to junction breakdown. For reliable operation, ST recommends keeping VI ≤ -20 V under full load to maintain adequate power dissipation margin and thermal stability in TO-220FP packaging.

Does L7905CV-DG require external capacitors, and what types are specified?

Yes: a minimum 2.2 µF solid tantalum capacitor at the input (CI) and 1 µF solid tantalum at the output (CO) are mandatory for stability per ST's test circuit. Aluminum electrolytic capacitors may be used only if capacitance is increased tenfold (e.g., 10 µF input, 10 µF output), and a reverse-biased 1N4001 diode must be added across input/output if large CO values are employed.

Can L7905CV-DG be used in parallel for higher current output?

Yes - the datasheet provides a high-current configuration (Figure 7) using an external PNP transistor to extend output capability to 4 A with current limiting. Direct parallel connection of multiple L7905CV-DG units is not recommended due to mismatched output voltages causing current hogging; external ballast resistors or active current-sharing circuits are required for safe paralleling.

Is L7905CV-DG pin-compatible with older L7905C variants?

Yes - L7905CV-DG uses the same TO-220FP package and identical pinout (Input-Ground-Output) as L7905C and L7905CV. It replaces those parts with identical electrical behavior plus enhanced thermal resistance (R_thJC = 5 °C/W) and full ECOPACK® compliance, enabling direct drop-in upgrades in existing designs without layout changes.