LT3505IDD#PBF

Overview

The LT3505IDD#PBF is a current mode PWM step-down DC/DC converter featuring an internal 1.4A power switch. It operates with an input voltage range of 3.6V to 36V, supporting a maximum of 40V. The device delivers up to 1.2A output current with adjustable output voltage down to 780mV. Switching frequency is resistor-programmable from 200kHz to 3MHz. It includes cycle-by-cycle current limit, soft-start, and shutdown mode with less than 2µA quiescent current. The component is housed in a thermally enhanced 3mm x 3mm DFN-8 package.

Feature Summary

• Wide operating input range suitable for unregulated wall transformers, industrial supplies, and automotive batteries
• Resistor-programmable fixed-frequency operation allows optimization between efficiency and external component size
• Low shutdown current enables easy power management in battery-powered systems by disconnecting the output

Applications

• Regulating power from unregulated wall transformers
• Power supply regulation for 24V industrial systems
• Automotive battery voltage regulation

Procurement Notes

Verify the specific suffix #PBF indicates lead-free tape and reel packaging status against the manufacturer's official documentation. Confirm the part number corresponds to the DFN-8 package variant. Ensure compatibility with required thermal dissipation standards for the target application environment before finalizing procurement specifications.

Selection Notes

Select this component when a wide input voltage range up to 36V is required alongside high efficiency at moderate currents. The programmable switching frequency allows designers to minimize passive component footprint or maximize efficiency based on specific design constraints. The low shutdown current makes it suitable for applications requiring extended battery life during standby modes.

Part Context

The LT3505 belongs to Analog Devices' family of high-voltage step-down switching regulators. It is designed to replace linear regulators in applications where input voltages significantly exceed output requirements, thereby reducing heat dissipation. The device integrates protection features such as soft-start and current limiting to ensure robust performance in demanding industrial and automotive environments.

Replacement Considerations

Consult official substitution guides for equivalent parts within the LT3505 series or compatible high-voltage buck converters. Verify pinout compatibility and thermal characteristics when considering alternative manufacturers.