LM2576SX-3.3

Voltage Regulators - DC DC Switching Regulators Overview

The LM2576SX-3.3 is a SIMPLE SWITCHER series monolithic integrated circuit step-down (buck) switching regulator manufactured by Texas Instruments. It provides a fixed 3.3V output with a guaranteed maximum load current of 3A. The device operates from an input voltage range of 4V to 40V and utilizes a fixed-frequency internal oscillator at 52kHz. Designed for high efficiency, it serves as a replacement for linear regulators, reducing heat sink requirements. The component features cycle-by-cycle current limiting and thermal shutdown protection.

Voltage Regulators - DC DC Switching Regulators Feature Summary

• Fixed 3.3V output voltage with excellent line and load regulation capabilities
• Integrated 52kHz fixed-frequency oscillator requiring minimal external components
• Internal frequency compensation simplifies design and reduces part count
• Built-in thermal shutdown and cycle-by-cycle current limiting for fault protection

Voltage Regulators - DC DC Switching Regulators Applications

• Simple and efficient buck converters
• High-efficiency pre-regulators for linear regulators
• On-card switching regulators
• Positive-to-negative converter implementations

Voltage Regulators - DC DC Switching Regulators Procurement Notes

Verify the specific suffix configuration when ordering, as availability varies between standard and lead-free (NOPB) versions. Confirm package integrity upon receipt, as the TO-263 form factor requires careful handling during surface mount assembly. Ensure compatibility with existing PCB footprints designed for the five-pin D2PAK style before finalizing procurement quantities.

Voltage Regulators - DC DC Switching Regulators Selection Notes

Select this component for applications requiring a robust 3A buck solution with a wide input voltage range up to 40V. The fixed 3.3V output eliminates the need for external feedback resistors, simplifying the bill of materials. Consider the 52kHz switching frequency when designing magnetic components, as lower frequencies necessitate larger inductors compared to modern high-frequency alternatives.

Voltage Regulators - DC DC Switching Regulators Part Context

This device belongs to the LM2576 family of SIMPLE SWITCHER regulators, originally introduced by National Semiconductor and continued by Texas Instruments after acquisition. The SX variant specifically denotes the surface-mount TO-263 (D2PAK) package. This series is widely recognized for its ease of use and reliability in industrial and commercial power supply designs requiring moderate current levels.

Voltage Regulators - DC DC Switching Regulators Replacement Considerations

Direct pin-compatible replacements include the LM2576S-3.3 and LM2576T-3.3 variants, differing primarily in package type. Cross-manufacturer equivalents such as those from JSMSEMI may offer functional parity but require verification of electrical tolerances and thermal characteristics against original specifications.