Overview
Features and Benefits
- High Efficiency: Up to 94%
- Very Low No-Load Quiescent Current: Only 16µA (LTC3801)
- High Output Currents Easily Achieved
- Internal Soft-Start
- Wide VIN Range: 2.4V to 9.8V
- Low Dropout: 100% Duty Cycle
- Constant Frequency 550kHz Operation
- Burst Mode® Operation for High Efficiency at Light Loads (LTC3801)
- Burst Mode Operation Disabled for Lower Output Ripple at Light Loads (LTC3801B)
- Output Voltage as Low as 0.8V
- ±1.5% Voltage Reference Accuracy
- Current Mode Operation for Excellent Line and Load Transient Response
- Only 6µA Supply Current in Shutdown (LTC3801)
- Low Profile (1mm) SOT-23 Package
Product Details
The LTC3801/LTC3801B are constant frequency current mode step-down DC/DC controllers in a low profile (1mm max) 6-lead SOT-23 (ThinSOT) package. The parts provide excellent AC and DC load and line regulation with ±1.5% output voltage accuracy. The LTC3801 consumes only 195µA of quiescent current in normal operation, dropping to 16µA under no-load conditions.
The LTC3801/LTC3801B incorporate an undervoltage lockout feature that shuts down the device when the input voltage falls below 2.2V. The LTC3801 automatically switches into Burst Mode operation at light loads which enhances efficiency at low output current. In the LTC3801B, Burst Mode operation is disabled for lower output ripple at light loads.
To further maximize the life of a battery source, the external P-channel MOSFET is turned on continuously in dropout (100% duty cycle). High switching frequency of 550kHz allows the use of a small inductor.
Applications
- 1- or 2-Cell Li-Ion Battery-Powered Applications
- Wireless Devices
- Portable Computers
- Distributed Power Systems
Product Lifecycle
Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (1)
Documentation
Reliability Data (1)
User Guides (1)
Tools & Simulations
LTspice
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.

Models for the following parts are available in LTspice:
Reference Materials
Technical Articles (2)
Design Resources
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.
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Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.