STMicroelectronics L7906CV

Overview

L7906CV from STMicroelectronics is a three-terminal fixed negative voltage regulator delivering -6 V output at up to 1.5 A, featuring thermal overload protection, short-circuit protection, and SOA-limited output transition capability. It operates with input voltages down to -35 V (for -6 V output), supports local on-card regulation, and is commonly used in split ±15 V power supplies for op-amp circuits and analog signal conditioning stages.

For engineers reviewing the L7906CV datasheet, L7906CV pinout, L7906CV application, or L7906CV equivalent, key selection criteria include guaranteed -6 V output tolerance (±5%), dropout voltage of 1.4 V at 1 A, junction temperature range of 0–150 °C, and TO-220FP package compatibility with standard heat sink mounting.

Technical Context

The L7906CV implements a monolithic PNP pass transistor-based linear regulation architecture with internal current limiting, thermal shutdown, and safe operating area (SOA) protection. Its feedback loop maintains stable -6 V output across load currents from -5 mA to -1.5 A and input variations from -9 V to -21 V.

It requires external input (≥2.2 µF solid tantalum) and output (≥1 µF) capacitors for stability and ripple rejection. Unlike adjustable regulators, it uses no external resistors - output voltage is factory-trimmed and non-programmable.

Key Specifications

Pinout & Package

Supplied in TO-220FP package: 3-pin vertical mount with metal tab (collector/heat sink connection), insulated from pins. Pin 1 = Input, Pin 2 = Ground, Pin 3 = Output.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM337T and MC7906CT, the L7906CV provides integrated SOA protection and factory-trimmed fixed output in an insulated TO-220FP package - simplifying design, reducing component count, and enhancing reliability in space-constrained analog systems.

Availability

L7906CV is available at Aetrix Electronics and suitable for industrial sensor interfaces, audio signal conditioning, split-rail power supplies, and legacy analog equipment repair requiring stable component supply and long-term manufacturability.

Supply support for L7906CV 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 analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The L79xxC series was developed specifically for robust, cost-effective local negative voltage regulation in analog and mixed-signal systems - emphasizing thermal resilience, fault protection, and compatibility with the complementary L78xx positive regulator family.

FAQ

What is the minimum input voltage required for stable -6 V output from the L7906CV?

The L7906CV requires a minimum input voltage of -7.4 V to maintain regulation at 1 A load (based on 1.4 V dropout). For reliable operation across temperature and line variation, ST recommends VI ≤ -9 V. Input below -7.4 V causes output to track input, losing regulation.

Can the L7906CV be used in parallel to increase output current?

No - the L7906CV is not designed for parallel operation. Its output voltage tolerance (±5%) and thermal drift characteristics prevent balanced current sharing. Attempting parallel use risks thermal runaway and premature failure. Use a single higher-current regulator or external pass transistor instead.

Is a heat sink mandatory for the L7906CV at 1 A output current?

Yes - at 1 A with a 10 V input-to-output differential (-16 V input → -6 V output), power dissipation is ~10 W. With R_thJC = 5 °C/W and ambient at 50 °C, junction temperature would exceed 150 °C without a heatsink. A 10 °C/W heatsink is recommended for continuous 1 A operation.

Does the L7906CV require an input bypass capacitor, and what type is specified?

Yes - ST specifies a minimum 2.2 µF solid tantalum capacitor between input and ground, placed within 1 cm of the input pin. Aluminum electrolytic capacitors are not recommended unless rated ≥22 µF due to higher ESR, which may compromise stability and transient response.