Features and Benefits
- Regulated Output with Input Voltages Above, Below or Equal to the Output
- 1.8V to 5.5V (Input) and 5.25V (Output) Voltage Range
- 0.8A Continuous Output Current: VIN > 1.8V
- 2A Continuous Output Current: VIN > 3V
- Single Inductor
- Synchronous Rectification: Up to 96% Efficiency
- Programmable Burst Mode® Operation: IQ = 40µA
- Output Disconnect in Shutdown
- Programmable Frequency from 300kHz to 2MHz
- <1µA Shutdown Current
- Small Thermally Enhanced 14-Lead (3mm × 4mm × 0.75mm) DFN package
The LTC3533 is a wide VIN range, highly efficient, fixed frequency, buck-boost DC/DC converter that operates from input voltages above, below or equal to the output voltage. The topology incorporated in the IC provides a continuous transfer function through all operating modes, making the product ideal for single cell lithium-ion/polymer or multi-cell alkaline/NiMH applications where the output voltage is within the input voltage range.
The LTC3533 features programmable Burst Mode operation, extended VIN and VOUT ranges down to 1.8V, and increased output current. Switching frequencies up to 2MHz are programmed with an external resistor. The Burst Mode threshold is programmed with a single resistor from the BURST pin to GND.
Other features include 1µA shutdown current, short circuit protection, programmable soft-start, current limit and thermal shutdown. The LTC3533 is housed in the thermally enhanced 14-lead (3mm × 4mm × 0.75mm) DFN package.
- GSM Modems
- Handheld Instruments
- Digital Cameras
- Smart Phones
- Media Players
- Miniature Hard Disk Drive Power
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 999A is a wide input range, 3.3V, synchronous buck-boost converter featuring the LTC3533. This circuit is designed to demonstrate the high level of performance, efficiency and small solution size attainable using this part in a buck-boost power supply. It operates at 1MHz and produces a regulated 3.3V from an input voltage range of 2.4V to 5.5V, and operates down to 1.8V with de-rated output current.
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:
LTC3533 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.