STMicroelectronics

L78S09CV

L78S09CV Description

The L78S09CV from STMicroelectronics is a fixed-output linear voltage regulator designed to deliver a stable 9V output at up to 2A of continuous current. With a wide input voltage range of up to 35V, this regulator is suitable for applications requiring robust voltage conversion from higher input sources. Housed in a TO-220AB package, the L78S09CV offers through-hole mounting for easy integration into power supply circuits. Although marked as obsolete, it remains a reliable choice for legacy designs due to its proven performance and compliance with ROHS3 and REACH environmental standards.

L78S09CV Features

• High Output Current: Supports 2A load current, making it suitable for power-hungry applications.
• Wide Input Range: Accepts input voltages up to 35V, accommodating varied power sources.
• Built-in Protections: Includes over-current, over-temperature, and short-circuit safeguards for enhanced reliability.
• Low Dropout Performance: Operates efficiently with a quiescent current of 8 mA.
• Excellent Noise Rejection: 47dB PSRR (120Hz) ensures clean output in noisy environments.
• Industrial-Grade Durability: Rated for 0°C to 150°C operation, ideal for harsh conditions.

L78S09CV Applications

The L78S09CV excels in systems requiring stable 9V power rails, such as:

• Industrial Control Systems: Powering sensors, actuators, and control modules.
• Consumer Electronics: Used in audio amplifiers, set-top boxes, and legacy devices.
• Automotive Electronics: Suitable for non-critical auxiliary systems due to its rugged design.
• Embedded Systems: Provides reliable voltage regulation for microcontrollers and peripherals.

Conclusion of L78S09CV

While newer alternatives exist, the L78S09CV remains a dependable choice for engineers seeking a high-current, fixed 9V regulator with robust protection features. Its wide input range, thermal resilience, and noise immunity make it well-suited for industrial and automotive applications. For legacy designs or systems requiring proven performance, this regulator delivers consistent power management despite its obsolete status.