STMicroelectronics L7808ACF

Overview

L7808ACF from STMicroelectronics is a three-terminal positive linear voltage regulator delivering a fixed 8 V output with ±2% tolerance at 25 °C, 1.5 A maximum output current, thermal overload and short-circuit protection, and operation across 0 to 125 °C junction temperature range. It serves as a local on-card power supply in industrial control modules, automotive body electronics, and embedded sensor interfaces requiring stable low-noise DC power.

For engineers reviewing the L7808ACF datasheet, L7808ACF pinout, L7808ACF application, or L7808ACF equivalent, key selection considerations include dropout voltage (2 V @ 1 A), load regulation (≤100 mV over 5 mA–1.5 A), supply voltage rejection (62 dB @ 120 Hz), output noise (52 µV/VO, 10 Hz–100 kHz), and TO-220FP package thermal resistance (R_thJC = 5 °C/W).

Technical Context

The L7808ACF implements a monolithic silicon-based series pass transistor architecture with internal current limiting, safe operating area (SOA) protection, and thermal shutdown circuitry. Its regulation loop maintains output stability under varying line (VI = 10.5–25 V) and load (IO = 5 mA–1.5 A) conditions without external compensation.

Designed for fixed-voltage operation, it accepts unregulated DC input and delivers low-ripple 8 V output with minimal external components-only 0.33 µF input and 0.1 µF output capacitors required per test circuits. The device operates without minimum load requirement beyond 5 mA for regulation compliance.

Key Specifications

Pinout & Package

Supplied in TO-220FP package-a thermally enhanced variant of TO-220 with isolated tab and vertical lead frame-enabling direct heatsink mounting while maintaining electrical isolation. Pinout is standardized across L78xx regulators.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM7808CDT/NOPB, L7808ACF adds SOA protection and tighter thermal shutdown; versus MC7808CD2TR4G, it offers lower thermal resistance (5 vs. 65 °C/W) and lower quiescent current (8 vs. 10 mA), making it preferable for thermally demanding through-hole designs.

Availability

L7808ACF is available at Aetrix Electronics and suitable for industrial PLC I/O modules, automotive body control units, medical patient monitor front-ends, and POS terminal power management requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for L7808ACF 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, MCU, power, and sensing solutions for industrial, automotive, and consumer markets.

The L78 series belongs to ST's legacy linear regulator product line, engineered for high reliability, intrinsic protection, and ease of use in cost-sensitive, thermally constrained applications where simplicity and ruggedness are prioritized over ultra-low quiescent current or adjustable output.

FAQ

What is the minimum input voltage required for stable 8 V output at 1.5 A?

The L7808ACF requires a minimum input voltage of 10 V to maintain regulation at 1.5 A load, based on its 2 V dropout specification and 8 V nominal output. Input must remain ≥10.5 V across all operating temperatures and line/load transients to guarantee compliance with the ±2% output tolerance.

Can L7808ACF be used without an input capacitor?

No-STMicroelectronics specifies a minimum 0.33 µF ceramic capacitor between IN and GND, placed within 1 cm of the device. Omitting it risks oscillation, poor transient response, and potential damage during input voltage spikes or hot-plug events, as confirmed by test circuit requirements in DS0422 Rev 38.

How does thermal performance differ between TO-220FP and standard TO-220 packages?

The TO-220FP package has R_thJC = 5 °C/W (vs. 5 °C/W for TO-220) but achieves lower effective R_thJA (60 °C/W vs. 50 °C/W) due to its isolated tab design enabling direct heatsink attachment without insulating washers. This yields ~10–15% higher continuous power capability under identical heatsinking conditions.

Is L7808ACF compatible with lead-free reflow soldering processes?

Yes-L7808ACF in TO-220FP package is rated for lead-free reflow per JEDEC J-STD-020, with peak reflow temperature of 260 °C (10-second duration). The device meets RoHS Directive 2011/65/EU and is marked with "RoHS" and "Pb-free" identifiers per ST's packaging standards.