EL7551CUZ

Overview

The EL7551CUZ is a monolithic synchronous step-down switching regulator manufactured by Renesas (formerly Intersil). It integrates a high-side N-channel MOSFET and a low-side N-channel MOSFET to achieve efficient DC-DC conversion. The device operates with an input voltage range of 4.5V to 36V and provides a regulated output current up to 1A. It features a fixed internal switching frequency of 200kHz, which allows for the use of small external inductors and capacitors. The IC includes comprehensive protection mechanisms such as thermal shutdown, cycle-by-cycle current limiting, and undervoltage lockout.

Feature Summary

• Integrated synchronous rectification utilizing dual N-channel MOSFETs for enhanced efficiency
• Fixed 200kHz switching frequency enabling compact passive component selection
• Built-in thermal shutdown and cycle-by-cycle current limiting for robust operation

Applications

• Point-of-load regulation for industrial control systems
• Battery-powered equipment requiring efficient step-down conversion
• Telecommunications infrastructure power distribution

Procurement Notes

Verify the specific suffix (e.g., T13) against the required tape-and-reel quantity or lead-free status, as these affect packaging but not electrical function. Confirm end-of-life status with the manufacturer, as this part may be discontinued. Ensure the operating temperature range matches the application environment requirements before finalizing procurement.

Selection Notes

Select this component when a compact, high-efficiency solution is needed for converting higher voltages down to lower logic or analog supply levels. The fixed 200kHz frequency simplifies filter design compared to adjustable frequency regulators. Consider the SOIC-8 package constraints for thermal dissipation if operating near maximum load currents.

Part Context

This component belongs to the EL7551 family of synchronous buck converters. It is designed to replace older asynchronous designs by integrating the low-side switch, thereby reducing component count and improving overall system efficiency. The device represents a transition in Intersil's portfolio towards highly integrated power management solutions for portable and industrial applications.

Replacement Considerations

Check for direct pin-compatible successors from Renesas such as the ISL8100 series or newer synchronous buck regulators. Verify that any substitute maintains the 200kHz frequency or adjusts compensation networks accordingly. Ensure the replacement supports the same 4.5V to 36V input range.