LM2576T-3.3/LB03

Voltage Regulators - DC DC Switching Regulators Overview

The LM2576T-3.3/LB03 is a monolithic integrated circuit from the Texas Instruments SIMPLE SWITCHER family, functioning as a step-down (buck) switching regulator. It provides a fixed 3.3V output with a guaranteed maximum load current of 3A. The device operates with an input voltage range up to 40V and utilizes a fixed-frequency internal oscillator at 52kHz. It incorporates internal frequency compensation and requires only four external components for operation. Key protection features include cycle-by-cycle current limiting and thermal shutdown.

Voltage Regulators - DC DC Switching Regulators Feature Summary

• Integrated high-current power switch capable of driving 3A loads
• Fixed 52kHz internal oscillator simplifies design and reduces component count
• Internal frequency compensation eliminates need for external compensation networks
• External shutdown pin enables low-power standby mode

Voltage Regulators - DC DC Switching Regulators Applications

• Efficient replacement for three-terminal linear regulators in DC-DC conversion
• Pre-regulator stages for downstream linear regulators
• Direct conversion from battery voltages to lower logic supply levels
• Positive-to-negative inversion circuits

Voltage Regulators - DC DC Switching Regulators Procurement Notes

Verify the specific suffix LB03 against the manufacturer datasheet to confirm package type and marking codes. Ensure compatibility with standard TO-220 mounting requirements. Confirm RoHS compliance status if required by project specifications. Cross-reference the part number with official Texas Instruments documentation to validate availability and revision history before procurement.

Voltage Regulators - DC DC Switching Regulators Selection Notes

Select this component when a simple, cost-effective buck converter solution is needed for moderate current applications. It is suitable for designs where a fixed 52kHz switching frequency is acceptable. Consider the thermal performance of the TO-220 package under full load conditions. This regulator is appropriate for replacing linear regulators where efficiency and heat dissipation are primary concerns.

Voltage Regulators - DC DC Switching Regulators Part Context

This part belongs to the LM2576 series, a long-standing line of SIMPLE SWITCHER power controllers. The 'T' indicates a through-hole TO-220 package, while '3.3' denotes the fixed 3.3V output voltage. The 'LB03' suffix typically specifies the package variant and environmental compliance details within the Texas Instruments product lineup.

Voltage Regulators - DC DC Switching Regulators Replacement Considerations

LM2576T-3.3/NOPB serves as a direct lead-free replacement within the same series. Other variants such as LM2576S-3.3 or LM2576M-3.3 offer surface-mount alternatives with identical electrical characteristics but different physical packages.