LM2575-3.3BU

Voltage Regulators - DC DC Switching Regulators Overview

The LM2575-3.3BU is a monolithic integrated circuit providing all active functions for a step-down (buck) switching regulator. It drives a 1A load with excellent line and load regulation, offering a fixed 3.3V output from an input voltage range of 4V to 40V. The device operates at a switching frequency of 52kHz and includes internal frequency compensation. Key protection features include thermal shutdown and per-cycle current limiting. It serves as a high-efficiency alternative to three-terminal linear regulators, significantly reducing heat sink requirements.

Voltage Regulators - DC DC Switching Regulators Feature Summary

• Integrated buck switching regulator topology with fixed 3.3V output
• Built-in thermal shutdown and per-cycle current limiting for system safety
• Internal frequency compensation simplifies external component requirements
• High efficiency reduces thermal management needs compared to linear regulators

Voltage Regulators - DC DC Switching Regulators Applications

• Point-of-load DC/DC conversion modules
• Pre-regulator stages for downstream linear regulators
• Battery-powered systems requiring efficient step-down conversion
• General-purpose power supply designs

Voltage Regulators - DC DC Switching Regulators Procurement Notes

Verify the manufacturer marking against Microchip Technology specifications, as NS markings may indicate older National Semiconductor stock or third-party sources. Confirm the package type matches the required TO-263 form factor. Ensure the operating temperature range meets application requirements, noting that commercial variants typically support up to 85°C while industrial versions extend to 125°C. Cross-reference datasheets for specific electrical tolerances.

Voltage Regulators - DC DC Switching Regulators Selection Notes

Select this component when a fixed 3.3V output is required with up to 1A load current. It is suitable for designs prioritizing simplicity and cost over ultra-high efficiency. Consider the TO-263 package for through-hole mounting or thermal dissipation needs. Evaluate the 52kHz switching frequency against EMI constraints. Compare against adjustable versions if variable output is needed later in the design phase.

Voltage Regulators - DC DC Switching Regulators Part Context

The LM2575 series comprises standard voltage, high-voltage input, and military-grade variants. This specific part belongs to the standard voltage family, distinct from the LM2575HV which supports higher input voltages. The series is widely recognized for replacing linear regulators in applications where size and thermal performance are critical constraints.

Voltage Regulators - DC DC Switching Regulators Replacement Considerations

Direct pin-compatible substitutes include the LM2575T-5.0/NOPB for different voltage outputs within the same package family. Other manufacturers produce equivalent buck regulators, but verify switching frequency and pinout compatibility before substitution.