LTC3440 - Micropower Synchronous Buck-Boost DC/DC Converter
- Single Inductor
- Fixed Frequency Operation with Battery Voltages
- Above, Below or Equal to the Output
- Synchronous Rectification: Up to 96% Efficiency
- 25µA Quiescent Current in Burst Mode® Operation
- Up to 600mA Continuous Output Current
- No Schottky Diodes Required (VOUT < 4.3V)
- VOUT Disconnected from VIN During Shutdown
- 2.5V to 5.5V Input and Output Range
- Programmable Oscillator Frequency from 300kHz to 2MHz
- Synchronizable Oscillator
- Burst Mode Enable Control
- <1µA Shutdown Current
- Small Thermally Enhanced 10-Pin MSOP and (3mm × 3mm) DFN Packages
The LTC3440 is a high efficiency, 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 lithium-ion, multicell alkaline or NiMH applications where the output voltage is within the battery voltage range.
The device includes two 0.19Ohm N-channel MOSFET switches and two 0.22Ohm P-channel switches. Switching frequencies up to 2MHz are programmed with an external resistor and the oscillator can be synchronized to an external clock. Quiescent current is only 25µA in Burst Mode operation, maximizing battery life in portable applications. Burst Mode operation is user controlled and can be enabled by driving the MODE/SYNC pin high. If the MODE/SYNC pin has either a clock or is driven low, then fixed frequency switching is enabled.
Other features include a 1µA shutdown, soft-start control, thermal shutdown and current limit. The LTC3440 is available in the 10-pin thermally enhanced MSOP package.
Protected by U.S. Patents including 6404251, 6166527.
CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.
For complete and up to date package information and drawings, please refer to our packaging page
- Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
- Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
- Please refer to our general ordering information or the product datasheet for more details
Package Variations and Pricing
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Demo BoardsLinear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.
|DC425B||LTC3440EMS Demo Board (MSOP)| 1MHz, Synchronous Buck-Boost, Vin = 2.5V to 5.5V, Vout = 3.3V @ 0.6A||$75.00|
|DC797A||LTC3440EDD Demo Board (DFN) | 1MHz, Synchronous Buck-Boost, Vin = 2.5V to 5.5V, Vout = 3.3V @ 0.6A||$150.00|
- Palmtop Computers
- Handheld Instruments
- MP3 Players
- Digital Cameras
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