L4973D3.3

Voltage Regulators - DC DC Switching Regulators Overview

The L4973D3.3 is a monolithic step-down switching regulator manufactured by STMicroelectronics, designed to deliver up to 3.5A of output current. It features a fixed 3.3V output with ±1% accuracy and supports an operating input voltage range from 8V to 55V. The device utilizes BCD mixed technology with an internal power D-MOS transistor (typical RDS(on) of 0.15Ω) for high efficiency. Key electrical parameters include a switch frequency adjustable up to 300kHz, a maximum output voltage of 50V when configured externally, and a shutdown current of less than 1mA. It operates within a temperature range of -40°C to +150°C.

Voltage Regulators - DC DC Switching Regulators Feature Summary

• Integrated pulse-by-pulse current limiting and hiccup mode for short-circuit protection
• Inhibit pin enables zero current consumption during shutdown
• Voltage feedforward regulation improves transient response
• Built-in thermal shutdown and feedback disconnection protection

Voltage Regulators - DC DC Switching Regulators Applications

• Driving high-current white LEDs in series configurations
• General-purpose DC-DC conversion for industrial equipment
• Power supply stages for automotive electronics

Voltage Regulators - DC DC Switching Regulators Procurement Notes

Verify the specific suffix against the manufacturer's official datasheet to confirm package type and tape/reel specifications. Ensure the component grade matches the required environmental conditions. Cross-reference the ordering code with authorized distributors to validate authenticity and traceability before finalizing procurement orders.

Voltage Regulators - DC DC Switching Regulators Selection Notes

Select this component for applications requiring high input voltages up to 55V and substantial output currents. Consider the SOIC-20 package constraints regarding thermal dissipation when designing for higher switching frequencies. Verify that the external component selection supports the desired frequency range and output stability requirements.

Voltage Regulators - DC DC Switching Regulators Part Context

This part belongs to the L4973 family of buck converters from STMicroelectronics. It shares architectural similarities with other members like the L4978 but offers higher current capacity. The family is characterized by robust protection features and compatibility with standard surface-mount assembly processes.

Voltage Regulators - DC DC Switching Regulators Replacement Considerations

Direct substitutes may include other STMicroelectronics buck regulators with similar current ratings and input voltage ranges. Verify pinout compatibility and thermal performance characteristics before replacing the original component in existing designs.