L4973V5.1

Voltage Regulators - DC DC Switching Regulators Overview

The L4973V5.1 is a step-down monolithic power switching regulator manufactured by STMicroelectronics, delivering a fixed output voltage of 5.1V with a maximum current of 3.5A. It operates within an input voltage range of 8V to 55V and supports adjustable outputs up to 50V using external dividers. The device utilizes BCD mixed technology with an internal power D-MOS transistor featuring a typical R DS(on) of 0.15Ω. It offers a switching frequency up to 300kHz and includes features such as pulse-by-pulse current limit, hiccup mode for short circuit protection, thermal shutdown, and soft start. The component is housed in an 18-DIP package.

Voltage Regulators - DC DC Switching Regulators Feature Summary

• Delivers 3.5A output current at fixed 5.1V or adjustable voltages up to 50V
• Integrates internal power D-MOS transistor for high efficiency and fast switching
• Includes comprehensive protection mechanisms: thermal shutdown, hiccup mode, and feedback disconnection protection

Voltage Regulators - DC DC Switching Regulators Applications

• General-purpose DC-DC conversion in industrial systems
• Power supply stages for microprocessor-based applications requiring stable 5.1V rails
• Embedded systems operating within wide input voltage ranges (8V to 55V)

Voltage Regulators - DC DC Switching Regulators Procurement Notes

Verify the specific suffix V5.1 confirms the fixed 5.1V output variant, as other suffixes may indicate different fixed voltages or adjustable versions. Confirm the 18-DIP package availability matches assembly requirements. Check for end-of-life status or active production updates from STMicroelectronics before finalizing procurement plans.

Voltage Regulators - DC DC Switching Regulators Selection Notes

Select this component when a robust, through-hole buck converter is needed for currents up to 3.5A. Ensure the application requires an input voltage range compatible with 8V to 55V. Consider the 300kHz switching frequency for trade-offs between component size and electromagnetic interference. Verify that the thermal performance of the 18-DIP package suits the expected power dissipation in the target environment.

Voltage Regulators - DC DC Switching Regulators Part Context

The L4973 belongs to a family of step-down switching regulators from STMicroelectronics, including variants like L4970A and L4976. While the L4970A delivers higher current (10A) and the L4976 provides lower current (1A), the L4973 bridges these with a 3.5A capability. This specific model fixes the output at 5.1V, simplifying design compared to fully adjustable counterparts.

Voltage Regulators - DC DC Switching Regulators Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.