STMicroelectronics

L4931CD33

L4931CD33 Description

The L4931CD33 from STMicroelectronics is a fixed-output linear voltage regulator designed to deliver a stable 3.3V output with a maximum current of 250mA. This surface-mount IC operates with an input voltage range up to 20V, making it suitable for a variety of power supply applications. With a low dropout voltage of 0.8V at 250mA, it ensures efficient performance even when the input voltage is close to the output level. The device features over-current and over-temperature protection, enhancing reliability in demanding environments. Although marked as obsolete, it remains a robust choice for legacy designs due to its low quiescent current (1mA) and high PSRR (73dB to 55dB), which minimizes noise in sensitive circuits.

L4931CD33 Features

• Fixed 3.3V Output: Ensures precise voltage regulation for low-power devices.
• Low Dropout Voltage: 0.8V at 250mA enables operation with minimal headroom.
• High PSRR (73dB @ 120Hz): Superior noise rejection for clean power delivery.
• Low Quiescent Current (1mA): Optimizes power efficiency in battery-operated systems.
• Protection Mechanisms: Includes over-current and over-temperature safeguards.
• Wide Input Range (Up to 20V): Compatible with diverse power sources.
• RoHS3 Compliant & REACH Unaffected: Meets environmental and safety standards.

L4931CD33 Applications

The L4931CD33 is ideal for applications requiring stable, low-noise power:

• Embedded Systems: Powering microcontrollers, sensors, and low-power peripherals.
• Consumer Electronics: Used in portable devices, audio equipment, and IoT modules.
• Industrial Controls: Reliable voltage regulation for PLCs and automation systems.
• Automotive Electronics: Suitable for non-critical subsystems due to its robust protection features.
• Legacy Designs: A dependable choice for maintaining or upgrading older electronics.

Conclusion of L4931CD33

The L4931CD33 offers a balance of efficiency, reliability, and noise suppression, making it a versatile solution for low-power voltage regulation. While obsolete, its high PSRR, low dropout, and protection features ensure continued relevance in legacy and niche applications. Engineers seeking a cost-effective, stable 3.3V regulator with robust performance will find this IC a practical option, particularly in noise-sensitive or space-constrained designs.