LM2679SX-3.3

Voltage Regulators - DC DC Switching Regulators Overview

The LM2679SX-3.3/NOPB is a SIMPLE SWITCHER® 5A step-down voltage regulator manufactured by Texas Instruments. It operates with an input voltage range of 8V to 40V and provides a fixed 3.3V output at up to 5A. The device utilizes a buck topology with a fixed switching frequency of 260kHz. It features adjustable current limiting, soft-start capability, and thermal shutdown protection. The component is housed in a TO-263-8 (D2PAK) surface-mount package and supports operation temperatures from -40°C to +125°C.

Voltage Regulators - DC DC Switching Regulators Feature Summary

• Integrated low on-resistance DMOS power switch enables high efficiency exceeding 90% across various load conditions.
• Fixed 260kHz internal oscillator allows for the use of compact external components while minimizing electromagnetic interference.
• Built-in thermal shutdown and programmable peak current limit protect the device and load during fault conditions.

Voltage Regulators - DC DC Switching Regulators Applications

• Efficient system pre-regulators for linear regulators
• High-current battery chargers
• Post regulators for PWM controllers

Voltage Regulators - DC DC Switching Regulators Procurement Notes

Verify the complete part number suffix, specifically /NOPB, to ensure compliance with RoHS standards and lead-free specifications. Confirm the package type matches the required PCB footprint, as variations exist between through-hole and surface-mount versions within the broader LM2679 family. Cross-reference the manufacturer datasheet revision to ensure design compatibility with latest electrical characteristics.

Voltage Regulators - DC DC Switching Regulators Selection Notes

Select this component when a robust 5A buck converter is required with minimal external circuitry. The fixed 3.3V output eliminates the need for feedback resistors, simplifying the design process. Ensure the input voltage remains within the 8V to 40V range and that adequate thermal management is provided for the TO-263 package under maximum load conditions.

Voltage Regulators - DC DC Switching Regulators Part Context

This device belongs to the SIMPLE SWITCHER® family, designed for ease of use with minimal external components. Originally developed by National Semiconductor before its acquisition by Texas Instruments, the LM2679 series is widely recognized for its reliability in high-current DC/DC conversion applications. The SX suffix denotes the specific surface-mount D2PAK package variant.

Voltage Regulators - DC DC Switching Regulators Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation. Designers should consult official Texas Instruments resources or authorized distributors for verified cross-references and pin-compatible alternatives.