Features and Benefits
- Regulated Output with Input Above, Below or Equal to the Output
- Single Inductor
- Up to 90% Efficiency
- VIN Range: 1.8V to 5.5V
- 200mA at 3.3VOUT from 3.6V Input
- 125mA at 3VOUT from 2.5V Input
- Fixed VOUT Versions (TSOT, DFN): 3.3V, 3V
- Adjustable VOUT Version (DFN): 2V to 5V
- Burst Mode® Operation, No External Compensation
- Ultra Low Quiescent Current: 16μA, Shutdown Current <1μA
- Only 3 External Components Required
(Fixed Voltage Versions)
- Short-Circuit Protection
- Output Disconnect in Shutdown
- Available in 6-Pin ThinSOT and 3mm × 3mm DFN Packages
The LTC3531/LTC3531-3.3/LTC3531-3 are synchronous buck-boost DC/DC converters that operate from input voltages above, below or equal to the output voltage. The topology incorporated in the ICs provides a continuous transfer through all operating modes, making the product ideal for single cell Li-Ion and multicell alkaline or nickel applications. The converters operate in Burst Mode, minimizing solution footprint and component count as well as providing high conversion efficiency over a wide range of load currents.
The devices include two 0.5Ω N-channel MOSFET switches and two P-channel switches (0.5Ω, 0.8Ω). Quiescent current is typically 16μA, making the parts ideal for battery power applications. Other features include a <1μA shutdown current, current limiting, thermal shutdown and output disconnect. The parts are offered in a 6-pin ThinSOT™ package for fixed voltage versions or a 3mm × 3mm DFN package for fixed and adjustable versions.
- Handheld Instruments
- MP3 Players
- Handheld computers
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)
Demonstration circuit 877 is a high efficiency synchronous Buck-Boost converter using the LTC3531-3.3. The input range is from 1.8V to 5.5V making it ideal for single-cell Lithium-Ion, multicell alkaline or nickel battery applications. This converter can provide 200mA when the input voltage is above 2.9V.
The DC877 features the LTC3531-3.3 in a tiny 6-pin ThinSOT package. The converter operates in Burst Mode, which provides conversion efficiency over a wide range of load currents. It has minimum component count and tiny solution size. Other features include current limiting, thermal shutdown and output disconnect.
Tools & Simulations
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.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.
Models for the following parts are available in LTspice:
LTC3531 Companion Parts
Recommended Related Parts
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.
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.