L4973D5.1

Voltage Regulators - DC DC Switching Regulators Overview

The L4973D5.1 is a monolithic step-down switching regulator manufactured by STMicroelectronics, delivering a fixed output voltage of 5.1V with a maximum current capacity of 3.5A. It operates within an input voltage range of 8V to 55V and supports switching frequencies up to 300kHz. The device utilizes BCDMOS technology with an internal power D-MOS transistor featuring a typical on-resistance of 0.15Ω. It is housed in a 20-pin SOIC surface-mount package.

Voltage Regulators - DC DC Switching Regulators Feature Summary

• Integrated pulse-by-pulse current limiting and hiccup mode for robust short-circuit protection
• Voltage feed-forward regulation ensures stable performance across wide input voltage variations
• Includes soft start functionality to limit inrush current during startup sequences
• Features thermal shutdown and protection against feedback loop disconnection

Voltage Regulators - DC DC Switching Regulators Applications

• Industrial DC-DC conversion systems requiring high efficiency
• Automotive electronics power distribution networks
• General-purpose step-down power supply designs
• Embedded systems needing regulated 5.1V rails from higher bus voltages

Voltage Regulators - DC DC Switching Regulators Procurement Notes

Verify the specific suffix 'D' confirms the SOIC-20 surface mount package variant rather than the PDIP-18 through-hole version. Confirm RoHS compliance status and check for alternative pin-compatible devices if lead times are critical. Ensure design reviews account for the thermal dissipation requirements inherent to the SOIC package at full load currents.

Voltage Regulators - DC DC Switching Regulators Selection Notes

Select this component when a fixed 5.1V output is required without external divider adjustments. Choose the SOIC-20 package for automated surface-mount assembly processes. Consider the 3.5A current rating and 55V input tolerance to ensure adequate headroom for the target application's peak loads and transient conditions.

Voltage Regulators - DC DC Switching Regulators Part Context

This part belongs to the L4973 family of buck converters, which also includes variants like L4973D3.3 and L4973V5.1. While sharing core topology and protection features, the L4973D5.1 is distinguished by its fixed 5.1V output and SOIC-20 packaging, differentiating it from adjustable or DIP-packaged siblings.

Voltage Regulators - DC DC Switching Regulators Replacement Considerations

L4973D3.3: Offers identical package and features but provides a fixed 3.3V output instead of 5.1V.

Voltage Regulators - DC DC Switching Regulators FAQ

Does the L4973D5.1 support adjustable output voltages?

No, the L4973D5.1 variant provides a fixed 5.1V output. Adjustable outputs are available in other members of the L4973 series.

What is the maximum switching frequency supported by this device?

The device supports switching frequencies up to 300kHz, allowing for compact passive component selection.