L4978D

Voltage Regulators - DC DC Switching Regulators Overview

The L4978D is a monolithic step-down switching regulator from STMicroelectronics, delivering up to 2A output current. It supports an input voltage range of 8V to 55V and provides adjustable output voltages between 3.3V and 50V via an external divider. The device operates with a switching frequency adjustable up to 300kHz and features a typical on-resistance of 0.25Ω for high efficiency. It is housed in a 16-pin SOIC package (SO16W) and functions within a temperature range of -40°C to +150°C.

Voltage Regulators - DC DC Switching Regulators Feature Summary

• Integrated pulse-by-pulse current limiting with hiccup mode for short circuit protection
• Inhibit pin enables zero current consumption for power-down states
• Protection against feedback loop disconnection ensures stable operation
• Built-in soft-start function limits inrush current during startup

Voltage Regulators - DC DC Switching Regulators Applications

• Industrial control systems requiring wide input voltage ranges
• Automotive electronics operating within specified thermal limits
• General-purpose DC-DC conversion for embedded applications

Voltage Regulators - DC DC Switching Regulators Procurement Notes

Verify the specific suffix 'D' corresponds to the SO16W surface-mount package when ordering. Confirm RoHS compliance status through official manufacturer documentation or authorized distributors. Ensure the procurement channel provides traceability for automotive or industrial grade requirements. Cross-reference the part number with the latest datasheet revision to confirm pinout and electrical specifications match your design needs before finalizing purchase orders.

Voltage Regulators - DC DC Switching Regulators Selection Notes

Select the L4978D over through-hole variants like the L4978 when surface-mount assembly is required. Consider the 2A current capability and 55V maximum input voltage for compatibility with your power bus. Evaluate the SO16W package thermal performance against your expected power dissipation at the chosen switching frequency. Verify that the external component selection supports the desired output voltage range and stability requirements.

Voltage Regulators - DC DC Switching Regulators Part Context

The L4978D belongs to the L4978 series of buck converters from STMicroelectronics. This series utilizes BCD mixed technology to integrate a power D-MOS transistor with control logic. The 'D' designation specifically identifies the surface-mount SO16W variant, distinguishing it from the DIP-8 through-hole version. The family is designed for high-efficiency step-down applications with robust protection features.

Voltage Regulators - DC DC Switching Regulators Replacement Considerations

The L4978 is the through-hole equivalent within the same product family. Direct substitution requires verifying package compatibility and ensuring the PCB footprint supports the SO16W form factor. Electrical characteristics remain consistent across the series, but thermal management strategies may differ due to package variations.