STMicroelectronics

L4947

L4947 Description

The L4947 is a Linear Voltage Regulator IC by STMicroelectronics, designed to provide a stable 5V output at 500mA with a fixed output configuration. It features a maximum input voltage of 26V and a maximum supply current of 180mA. The L4947 is obsolete but remains a reliable choice for certain applications due to its REACH unaffected status and compliance with RoHS3 standards.

L4947 Features

• Fixed Output Type: Provides a stable 5V output voltage.
• High Output Current: Capable of delivering up to 500mA, making it suitable for applications requiring higher current.
• Single Regulator: Features one output regulator for straightforward implementation.
• Positive Output Configuration: Ideal for applications requiring a positive voltage reference.
• Low Voltage Dropout: Maintains regulation at 0.75V @ 500mA, ensuring stable operation under varying input voltages.
• Reset Control Feature: Includes reset functionality for enhanced system reliability.
• Protection Features: Offers over-temperature, reverse polarity, and short-circuit protection to safeguard the device and the system.
• Low Quiescent Current: Operates with a low 13mA quiescent current, reducing power consumption in standby modes.
• PSRR of 60dB: Provides excellent power supply rejection ratio at 120Hz, ensuring minimal noise coupling from the input to the output.

L4947 Applications

The L4947 is well-suited for applications where a stable 5V supply is needed at moderate currents. Some ideal use cases include:

• Portable Electronics: Powering low-power circuits in devices like digital cameras, MP3 players, and handheld gaming consoles.
• Industrial Controls: Providing a stable power supply for microcontrollers and sensors in industrial automation systems.
• Telecommunications:。
• Automotive Electronics: Used in low-current applications within the vehicle's infotainment and control systems.

Conclusion of L4947

While the L4947 is now considered obsolete, it still offers a robust solution for applications requiring a fixed 5V output at 500mA. Its combination of high output current, protection features, and low quiescent current make it an attractive choice for designers looking for a reliable, albeit older, voltage regulator. Despite its age, the L4947's performance benefits and unique features continue to make it a viable option in certain niche applications within the electronics industry.