STMicroelectronics L7805ACV

Overview

L7805ACV from STMicroelectronics is a three-terminal positive fixed-voltage linear regulator delivering 5 V ±2 % output with up to 1.5 A continuous current, thermal overload and short-circuit protection, and operation across 0 to 125 °C junction temperature. It serves as a local on-card power supply in industrial control modules, embedded sensor nodes, and legacy microcontroller power rails where low-noise, robust DC-DC conversion is required without switching complexity.

For engineers reviewing the L7805ACV datasheet, L7805ACV pinout, L7805ACV application, or L7805ACV 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 (68 dB at 120 Hz), quiescent current (4.3–6 mA), and thermal resistance (R_thJC = 5 °C/W in TO-220).

Technical Context

The L7805ACV implements a monolithic bipolar linear regulator architecture with internal current limiting, safe-area protection, and thermal shutdown-enabling self-protecting operation under sustained overload or ambient temperature extremes. Its fixed 5 V output is trimmed at 25 °C and drifts only −1.1 mV/°C over temperature.

It requires minimal external components: a 0.33 µF input ceramic capacitor and 0.1 µF output ceramic capacitor for stability. Dropout voltage remains constant at 2 V up to 1 A load, and output noise is specified at 10 µV/√Hz (10 Hz–100 kHz bandwidth), confirming suitability for analog-sensitive subsystems.

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 is electrically tied to Pin 2 and must be isolated from chassis if mounted to conductive heat sink.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM7805CT and MC7805BDTRKG, the L7805ACV offers superior supply rejection and lower thermal resistance in TO-220, making it optimal for thermally demanding industrial applications where long-term stability and ripple immunity outweigh footprint constraints.

Availability

L7805ACV is available at Aetrix Electronics and suitable for industrial sensor interfaces, legacy microcontroller power supplies, embedded communication modules, and test & measurement equipment requiring stable component supply with full traceability and long-lifecycle support.

Supply support for L7805ACV 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 automotive, industrial, and power management ICs with strong European manufacturing and quality certification.

The L78 series belongs to ST's legacy linear regulator product line, designed specifically for robust, low-cost, drop-in replacements of classic 78xx regulators in industrial and infrastructure applications where reliability and temperature resilience are prioritized over ultra-low IQ.

FAQ

What is the minimum input voltage required for regulation with L7805ACV?

The L7805ACV requires a minimum input voltage of 7.5 V to maintain 5 V output under full 1.5 A load, based on its 2 V dropout specification. At lighter loads (e.g., 100 mA), regulation holds down to ~7 V. Input below 7 V risks dropout and unregulated output, especially at elevated temperatures.

Can L7805ACV be used without a heatsink?

Yes - for loads ≤500 mA at ambient temperatures ≤40 °C with adequate PCB copper area (≥25 cm² 2 oz Cu on top/bottom layers). Above 500 mA or in enclosed enclosures, a heatsink is mandatory: R_thJA = 50 °C/W (TO-220) means 1 A load generates ~100 °C junction rise above ambient without heatsinking.

Does L7805ACV require input and output capacitors?

Yes - ST specifies a minimum 0.33 µF ceramic capacitor at the input and 0.1 µF ceramic capacitor at the output, placed as close as possible to their respective pins. Omitting either risks oscillation or poor transient response; tantalum or electrolytic caps alone are insufficient for stability.

How does L7805ACV behave during short-circuit conditions?

Under short circuit, the L7805ACV limits output current to ~0.2 A (typical) and activates thermal shutdown if junction temperature exceeds ~165 °C. After cooling, it auto-recovers. Peak short-circuit current reaches 2.2 A briefly, but safe-area protection prevents destructive second breakdown during this transient.