Small Size & Very High Efficiency Buck-Boost Converter

Many applications such as battery-powered supply have a wide input voltage that can be lower or higher than the regulated output voltage. The conventional solutions, such as flyback, Sepic or a 2-stage supply are usually complicated and inefficient.

The single-stage buck-boost converter only needs a small size inductor with good efficiency. With the LTC3780, the synchronous buck-boost converter can offer an impressive 8% to 10% efficiency gain over a typical flyback or Sepic solution. Furthermore, the 4-switch synchronous buck-boost converter can be integrated in a very small 15mm x 15mm x 3mm, 60W, LTM4605/7/9 power module with a single external inductor. With current mode control, the LTM460x modules can be easily paralleled for more current and power with good current sharing and thermal balance.

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References

Datasheets
LTC3780 - High Efficiency, Synchronous, 4-Switch Buck-Boost Controller
LTC3785 - 10V, High Efficiency, Synchronous, No RSENSE Buck-Boost Controller
LTM4605 - High Efficiency Buck-Boost DC/DC µModule
LTM4607 - 36VIN, 24VOUT High Efficiency Buck-Boost DC/DC µModule
LTM4609 - 36VIN, 34VOUT High Efficiency Buck-Boost DC/DC µModule

Design notes
DN369 - Industry's First 4-Switch Buck-Boost Controller Achieves Highest Efficiency Using a Single Inductor
DN424 - Buck-Boost Controller Simplifies Design of DC/DC Converters for Handheld Products
DN438 - µModule Buck-Boost Regulators Offer a Simple and Efficient Solution for Wide Input and Output Voltage Range Applications

LT Magazines
January 2009 - Parallel Buck-Boost µModule Regulators to Produce High Current in Sub-2.8mm Height Applications
March 2009 - µModule Regulator Fits a (Nearly) Complete Buck-Boost Solution in 15mm x 15mm x 2.8mm for 4.5V-36VIN to 0.8V-34VOUT