LT1938

PRODUCTION

25V, 2.2A, 2.8MHz Step-Down Switching Regulator

Part Models: 4
1ku List Price: Starting From $3.31

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Overview

Wide Input Voltage Range: 3.6V to 25V
2.2A Maximum Output Current
Adjustable Switching Frequency: 300kHz to 2.8MHz
Low Shutdown Current: I_Q < 1µA
Integrated Boost Diode
Power Good Flag
Saturating Switch Design: 0.18Ω On-Resistance
1.265V Feedback Reference Voltage
Output Voltage: 1.265V to 20V
Soft-Start Capability
Small 10-Pin Thermally Enhanced (3mm × 3mm) DFN Package

The LT1938 is an adjustable frequency (300kHz to 2.8MHz) monolithic buck switching regulator that accepts input voltages up to 25V. A high efficiency 0.18Ω switch is included on the die along with a boost Schottky diode and the necessary oscillator, control and logic circuitry. Current mode topology is used for fast transient response and good loop stability. The LT1938's high operating frequency allows the use of small, low cost inductors and ceramic capacitors resulting in low output ripple while keeping total solution size to a minimum. The low current shutdown mode reduces input supply current to less than 1µA while a resistor and capacitor on the RUN/SS pin provide a controlled output voltage ramp (soft-start). A power good flag signals when V_OUT reaches 90% of the programmed output voltage. The LT1938 is available in a 3mm × 3mm DFN package with Exposed Pad for low thermal resistance.

Applications

Automotive Battery Regulation
Power for Portable Products
Distributed Supply Regulation
Industrial Supplies
Wall Transformer Regulation

Part Models: 4
1ku List Price: Starting From $3.31

Documentation

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal. View our quality and reliability program and certifications for more information.

Part Model	Pin/Package Drawing	Documentation	CAD Symbols, Footprints, and 3D Models
LT1938EDD#PBF	10-Lead DFN (3mm x 3mm w/ EP)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LT1938EDD#TRPBF	10-Lead DFN (3mm x 3mm w/ EP)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LT1938IDD#PBF	10-Lead DFN (3mm x 3mm w/ EP)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LT1938IDD#TRPBF	10-Lead DFN (3mm x 3mm w/ EP)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys

Part Models	Product Lifecycle	PCN

Feb 14, 2025 - 25_0016 Bond Wire Change from Gold to Copper Wire (Notification Only)
		PCN25_0016_Form Material_Report Qualification Results Summary
LT1938EDD#PBF	PRODUCTION
LT1938EDD#TRPBF	PRODUCTION
LT1938IDD#PBF	PRODUCTION
LT1938IDD#TRPBF	PRODUCTION

This is the most up-to-date revision of the Data Sheet.

Software Resources

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Hardware Ecosystem

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Power System Management (PSM) & Sequencers 1
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Protection Switches & Controllers 1
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Switching Regulators & Controllers 1
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Tools & Simulations

LTspice 1

LT1938 Demo Circuit - 2.2A, 25V. 2.8MHz Step_down Regulator (24V to 3.3V @ 2.2A)

Models for the following parts are available in LTspice:

LT1938

LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.