STMicroelectronics

L78S18CV

L78S18CV Description

The L78S18CV from STMicroelectronics is a fixed-output linear voltage regulator designed to deliver a stable 18V output at up to 2A current. Housed in a TO-220AB package, this through-hole-mount IC operates over a wide input voltage range (up to 35V) and is engineered for robustness in demanding environments. With a quiescent current of 8 mA and a 43dB PSRR (120Hz), it ensures efficient noise suppression and reliable performance. The device features over-current, over-temperature, and short-circuit protection, making it suitable for applications requiring high reliability. Although marked as obsolete, its ROHS3 compliance and REACH-unaffected status ensure adherence to environmental standards.

L78S18CV Features

• Fixed 18V Output: Precision-regulated voltage for stable power delivery.
• High Current Capacity: Supports 2A continuous output current, ideal for power-hungry circuits.
• Wide Input Range: Accepts up to 35V input, accommodating fluctuating supply conditions.
• Built-in Protections: Includes over-current, over-temperature, and short-circuit safeguards for enhanced durability.
• Low Noise Operation: 43dB PSRR minimizes ripple and interference in sensitive applications.
• Industrial-Grade Reliability: Operates across 0°C to 150°C, suited for harsh environments.
• Through-Hole Design: TO-220AB package simplifies heatsinking and mechanical integration.

L78S18CV Applications

• Industrial Power Supplies: Provides stable voltage for control systems, PLCs, and motor drivers.
• Audio Amplifiers: Low-noise regulation ensures clean power for high-fidelity audio circuits.
• Test and Measurement Equipment: Reliable voltage reference for precision instruments.
• Automotive Electronics: Robust protection features suit auxiliary power in vehicles (non-critical systems).
• Legacy Systems Maintenance: Ideal for repairing or upgrading older equipment requiring 18V regulation.

Conclusion of L78S18CV

The L78S18CV is a high-performance linear regulator offering 18V fixed output, 2A current capability, and robust protection mechanisms. While obsolete, its industrial-grade tolerances, low noise, and through-hole design make it a dependable choice for legacy systems, industrial controls, and noise-sensitive applications. Engineers valuing durability and simplicity will find it a practical solution, though newer alternatives may be preferred for modern designs.