STMicroelectronics L7808ACV

Overview

L7808ACV from STMicroelectronics is a three-terminal positive linear voltage regulator delivering a fixed 8 V output at up to 1.5 A, with ±2 % output voltage tolerance (A version), thermal overload protection, short-circuit protection, and safe operating area (SOA) protection. It operates across 0 to 125 °C junction temperature and is commonly used for local on-card regulation in industrial power supplies and embedded control modules.

For engineers reviewing the L7808ACV datasheet, L7808ACV pinout, L7808ACV application, or L7808ACV equivalent, key selection considerations include dropout voltage (2 V @ 1 A), load regulation (≤30 mV over 5 mA–1.5 A), supply voltage rejection (62 dB @ 120 Hz), thermal resistance (R_thJC = 5 °C/W in TO-220), and guaranteed extended temperature operation.

Technical Context

The L7808ACV implements a monolithic series pass transistor architecture with internal current limiting, thermal shutdown, and SOA protection-enabling robust operation without external protection circuitry. Its feedback loop maintains regulation under varying line (VI = 10.6–25 V) and load (IO = 5 mA–1.5 A) conditions.

Designed for fixed-output use, it supports external capacitor stabilization (CI ≥ 0.33 µF, CO ≥ 0.1 µF) and can be adapted for adjustable output via external resistive networks. The device's 2 V dropout voltage and 18 mΩ output resistance define its low-noise, high-stability DC performance in point-of-load applications.

Key Specifications

Pinout & Package

Supplied in TO-220 package (3-pin, vertical mounting, metal tab connected to GND), with standard three-terminal configuration: Input (Pin 1), Ground (Pin 2), Output (Pin 3).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM340T-8.0 and MC7808CT, the L7808ACV provides tighter output tolerance, integrated thermal and SOA protection, and guaranteed operation across the full industrial temperature range-making it preferable for reliability-critical embedded systems.

Availability

L7808ACV is available at Aetrix Electronics and suitable for industrial PLC power rails, automotive body control modules, medical diagnostic instrumentation, and point-of-sale terminal logic supplies requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for L7808ACV 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 silicon solutions for automotive, industrial, and power management applications.

The L78 series belongs to ST's legacy positive voltage regulator IC product line, engineered for rugged, low-cost, fixed-output local regulation in harsh environments where simplicity, reliability, and thermal resilience are prioritized over ultra-low quiescent current or switching efficiency.

FAQ

What is the minimum input voltage required for stable 8 V output at 1 A?

The L7808ACV requires a minimum input voltage of 10.6 V under full-load (1 A) and room-temperature conditions, per Table 5 of DS0422 Rev 38. This accounts for its 2 V dropout voltage and worst-case line regulation. For reliable operation across temperature and load extremes, 11.5 V is recommended.

Can L7808ACV be used without an input bypass capacitor?

No-STMicroelectronics specifies a minimum 0.33 µF ceramic capacitor between Input and Ground, placed as close as possible to Pin 1. Omitting it risks oscillation, poor transient response, and potential instability due to parasitic inductance in the input path.

Does L7808ACV require a heatsink for 1 A continuous operation?

Yes-when delivering 1 A continuously in a TO-220 package, thermal calculations using R_thJA = 50 °C/W show junction temperature rise exceeding 125 °C at ambient >40 °C. A heatsink reducing R_thJA to ≤25 °C/W is required for full-load operation in typical industrial enclosures.

How does the L7808ACV behave during short-circuit conditions?

Under short-circuit, the L7808ACV limits output current to ~0.2 A (I_sc) while maintaining thermal shutdown activation if junction temperature exceeds 150 °C. It does not latch off-recovery occurs automatically once fault is removed and temperature falls below shutdown threshold.