LM3351MMX/NOPB

Voltage Regulators - DC DC Switching Regulators Overview

The LM3351MMX/NOPB is a high-efficiency, synchronous step-down switching regulator manufactured by Texas Instruments (formerly National Semiconductor). It integrates a 4.5V to 28V input range with an adjustable output voltage capability from 0.8V to 26V. The device operates at a fixed 500kHz switching frequency and supports up to 3A of continuous load current. Key features include integrated power MOSFETs, cycle-by-cycle current limiting, and thermal shutdown protection. It is housed in a thermally enhanced 16-pin MSOP package designed for surface-mount applications requiring compact power solutions.

Voltage Regulators - DC DC Switching Regulators Feature Summary

• Integrates high-side and low-side N-channel power MOSFETs for efficient synchronous rectification
• Provides constant-frequency peak current mode control architecture
• Includes comprehensive protection mechanisms such as cycle-by-cycle current limiting and thermal shutdown
• Supports remote voltage sensing for improved load regulation accuracy

Voltage Regulators - DC DC Switching Regulators Applications

• Point-of-load regulation for industrial equipment
• Power supplies for embedded systems and networking infrastructure
• Battery-powered devices requiring efficient DC-DC conversion
• General-purpose board-level power distribution

Voltage Regulators - DC DC Switching Regulators Procurement Notes

Verify the manufacturer designation carefully, as the part originates from National Semiconductor but is now distributed under the Texas Instruments brand. Confirm that the suffix /NOPB indicates lead-free and RoHS compliance. Ensure the MMX suffix corresponds to the correct tape-and-reel packaging format required for your assembly process. Cross-reference the specific date code and lot traceability if required by your quality management system standards.

Voltage Regulators - DC DC Switching Regulators Selection Notes

Select this component when designing a compact, high-efficiency buck converter requiring an input voltage up to 28V. It is suitable for applications needing up to 3A output current with minimal external component count. Consider the thermal performance of the MSOP package and ensure adequate PCB copper area for heat dissipation. Verify that the required output voltage range falls within the 0.8V to 26V adjustability limits of the internal reference.

Voltage Regulators - DC DC Switching Regulators Part Context

This device belongs to the LM335x family of synchronous step-down regulators. It shares architectural similarities with other members like the LM3350 and LM3352, differing primarily in maximum current handling and input voltage specifications. The LM3351 specifically targets mid-range power applications where efficiency and size are critical constraints compared to non-synchronous alternatives or higher-power variants.

Voltage Regulators - DC DC Switching Regulators Replacement Considerations

Direct pin-to-pin replacements may include the LM3351MMX or older National Semiconductor versions without the NOPB suffix. For upgraded performance, consider the LM3352 series for higher current capabilities. Always verify electrical parameters and thermal characteristics against the original design requirements before substituting.