LT3973IDD-3.3#PBF

Overview

The LT3973IDD-3.3#PBF is a monolithic buck switching regulator manufactured by Analog Devices Inc., housed in a 10-WFDFN exposed pad package. It features an adjustable output voltage range from 1.21V to 24V and supports a maximum continuous output current of 750mA. The device accepts a wide input voltage range up to 42V and operates with a quiescent current of only 2.5uA. The switching frequency is adjustable between 195kHz and 2.15MHz, allowing for optimization of external component size and efficiency. It functions as a positive, non-synchronous step-down converter suitable for surface mount installation across a temperature range of -40°C to 125°C.

Feature Summary

• Adjustable switching frequency allows optimization of performance versus size
• Ultra-low quiescent current minimizes power consumption in standby modes
• Wide input voltage range accommodates various supply sources
• Integrated thermal protection ensures reliable operation under overload conditions

Applications

• Automotive electronics requiring robust voltage regulation
• Industrial control systems needing stable DC-DC conversion
• Portable equipment utilizing battery or single-cell power sources
• Embedded systems demanding low standby power consumption

Procurement Notes

Verify the suffix #PBF indicates lead-free tin plating compliant with RoHS standards. Confirm the IDD suffix corresponds to the industrial temperature grade (-40°C to 125°C junction temperature). Ensure the specific part number matches the required fixed output configuration if applicable, though this model typically denotes the adjustable variant with internal feedback settings. Cross-reference the manufacturer's latest datasheet for any updates on pinout or recommended operating conditions before finalizing procurement orders.

Selection Notes

Select this component when designing circuits that require high input voltages up to 42V with minimal static power draw. The adjustable frequency feature enables designers to trade off between electromagnetic interference and passive component footprint. Consider the 750mA current limit for loads exceeding this threshold, where parallel configurations or higher-current alternatives may be necessary. The exposed pad package requires careful PCB thermal design to dissipate heat effectively during high-load operations.

Part Context

This part belongs to the LT3973 family of buck regulators, designed for applications prioritizing low quiescent current and flexible frequency selection. The IDD variant specifies the industrial temperature range and WDFN packaging. It complements other Analog Devices power management solutions by offering a compact, efficient step-down topology suitable for space-constrained designs requiring wide input voltage tolerance.

Replacement Considerations

Direct substitutes include other LT3973 variants with different suffixes indicating package or temperature variations, such as LT3973HDD for automotive grades. Verify compatibility regarding pinout, thermal characteristics, and electrical specifications before substitution. Generic replacements must match the 750mA output current, 42V max input, and adjustable frequency capabilities to ensure circuit functionality remains unchanged.