LM2678S-3.3

Voltage Regulators - DC DC Switching Regulators Overview

The LM2678S-3.3/NOPB is a monolithic integrated circuit implementing a SIMPLE SWITCHER high-efficiency step-down DC/DC switching regulator. It operates with an input voltage range of 8V to 40V and provides a fixed 3.3V output at up to 5A load current. The device utilizes a TO-263 (DDPAK) surface-mount package and features a switching frequency of 260kHz. Key electrical parameters include a maximum static current of 4.2mA, an operating temperature range from -40°C to +125°C, and internal protection against overcurrent and thermal overload.

Voltage Regulators - DC DC Switching Regulators Feature Summary

• Integrates all active functions for a buck converter topology including a low on-resistance DMOS power switch
• Provides inherent thermal shutdown and cycle-by-cycle current limiting for robust operation under fault conditions
• Delivers high efficiency exceeding 90% through optimized switching architecture and low conduction losses

Voltage Regulators - DC DC Switching Regulators Applications

• Point-of-load regulation in distributed power supply architectures
• High-current conversion from standard bus voltages such as 12V or 24V
• Battery-powered systems requiring efficient step-down conversion

Voltage Regulators - DC DC Switching Regulators Procurement Notes

Verify the specific suffix configuration, as the base model may be obsolete while the NOPB variant remains active. Confirm the package type matches the target PCB footprint, typically TO-263. Ensure compliance with RoHS directives if required by the final assembly specifications. Check for any process change notifications that might affect pin compatibility or material composition.

Voltage Regulators - DC DC Switching Regulators Selection Notes

Select this component when a fixed 3.3V output is required from an 8V to 40V input source. It is suitable for designs needing up to 5A continuous current with minimal external component count. Consider the thermal performance of the TO-263 package for heat dissipation requirements. Verify that the 260kHz switching frequency aligns with electromagnetic interference constraints and inductor size limitations.

Voltage Regulators - DC DC Switching Regulators Part Context

This part belongs to the LM2678 family of SIMPLE SWITCHER regulators, which includes adjustable and other fixed voltage variants like 5.0V and 12.0V. The series is designed for high-efficiency power management in industrial and consumer applications. The LM2678S-3.3 specifically targets applications requiring a stable 3.3V rail from higher voltage inputs without the complexity of discrete controller solutions.

Voltage Regulators - DC DC Switching Regulators Replacement Considerations

LM2678S-3.3/NOPB is the direct lead-free replacement for the older LM2678S-3.3. Other family members like LM2678S-5.0 or LM2678S-ADJ share identical pinouts and functionality but differ in output voltage settings.