E-L4978D

Overview

The L4978D is a step-down monolithic power switching regulator from STMicroelectronics, delivering up to 2A output current. It operates with an input voltage range of 8V to 55V and provides regulated output voltages adjustable from 3.3V to 50V via an external divider. The device utilizes BCD mixed technology with an internal D-MOS transistor featuring a typical Rds(on) of 0.25Ω. It supports switching frequencies up to 300kHz and includes features such as pulse-by-pulse current limiting, hiccup mode protection, soft-start, thermal shutdown, and inhibit functionality for zero current consumption.

Feature Summary

• Integrated high-efficiency power D-MOS transistor for high switching speed
• Comprehensive protection suite including hiccup mode and feedback disconnection detection
• Inhibit pin enables zero current consumption when disabled
• Adjustable switching frequency up to 300kHz

Applications

• Industrial power supply systems
• Automotive electronics applications
• General-purpose DC-DC conversion

Procurement Notes

Verify the exact suffix against official documentation, as 'E-' may indicate specific tape-and-reel packaging or environmental compliance variations not explicitly detailed in general summaries. Confirm package type (SO16W vs DIP-8) and temperature grade requirements match the specific order code. Cross-reference with STMicroelectronics datasheets to ensure functional equivalence before procurement.

Selection Notes

Select this component for applications requiring wide input voltage ranges up to 55V and high output currents. Consider the SO16W package for surface mount assembly needs. Evaluate thermal dissipation constraints given the 0.25Ω on-resistance at higher load conditions. Ensure the design accommodates the adjustable switching frequency limits and protection feature configurations.

Part Context

The L4978 belongs to the L4978 series of buck converters manufactured by STMicroelectronics. It is part of their broader portfolio of power management integrated circuits designed for robust performance in industrial and automotive environments. The device represents a generation of DC-DC converters emphasizing efficiency and integrated protection mechanisms.

Replacement Considerations

Direct substitutes include other L4978 variants such as L4978D013TR. Verify pin compatibility and electrical specifications before substitution.