LT1507IN8-3.3#PBF

Overview

The LT1507IN8-3.3#PBF is a fixed-output, step-down switching regulator from Analog Devices Inc., delivering a regulated 3.3V output. It operates with an input voltage range of 2.5V to 40V and provides up to 1A of continuous load current. The device integrates a high-side NPN power switch and utilizes a constant-frequency current-mode control architecture for rapid transient response. Operating at a fixed frequency of 500kHz, it achieves efficiencies exceeding 90% in typical applications. The component is housed in an 8-pin PDIP or SOIC package.

Feature Summary

• Integrates a high-current NPN power switch eliminating the need for external pass transistors
• Employs current-mode control architecture for inherent line and load regulation stability
• Features low dropout operation allowing efficient regulation near input voltage levels
• Includes comprehensive protection mechanisms such as thermal shutdown and cycle-by-cycle current limiting

Applications

• Battery-powered portable equipment requiring efficient voltage conversion
• Post-regulation stages for higher voltage DC-DC converters
• Linear regulator replacement for improved efficiency in low-dropout scenarios
• Isolated DC-DC converter bias supply generation

Procurement Notes

Verify the specific suffix '#PBF' confirms lead-free status and RoHS compliance when sourcing. Ensure the 'IN8' designation matches the required 8-pin package type (PDIP or SOIC) for your PCB layout. Confirm the '-3.3' indicates the fixed 3.3V output variant. Cross-reference the manufacturer's latest datasheet to ensure no obsolescence notices apply to this specific part number before finalizing procurement.

Selection Notes

Select this component when a fixed 3.3V output is required from an input voltage ranging between 2.5V and 40V. It is suitable for designs needing up to 1A load current with high efficiency. Consider the 500kHz switching frequency for inductor size trade-offs. Ensure the application does not require adjustable output voltages, as this is a fixed-output device. Verify thermal management requirements for the chosen package style under maximum load conditions.

Part Context

This part belongs to the LT1507 family of monolithic step-down switching regulators. These devices are designed to replace linear regulators where efficiency and heat dissipation are critical concerns. The family offers various fixed output voltages and adjustable versions, sharing the same core current-mode control topology and integrated power switch architecture for consistent performance characteristics across the series.

Replacement Considerations

Direct replacements include other LT1507 variants with different output voltages if system design allows adjustment. Check for newer generations from Analog Devices offering similar pinouts and electrical specifications. Verify that any substitute maintains the 500kHz frequency and 1A current capability. Ensure compatibility with existing passive components like inductors and capacitors.