DC/DC controller LTC3779 that can operate at input voltages above, below or equal to the regulated output voltage

Milpitas, Calif., and NORWOOD, MA – Linear Technology Corporation, a subsidiary of Analog Devices, Inc. (ADI), introduces high efficiency ( Up to 99%) 4 Switch Single Inductor Synchronous Buck-Boost DC/DC Controller LTC3779 , which operates with an input voltage above, below or equal to the regulated output voltage. Its 4.5V to 150V input voltage range allows operation with high input voltage sources or high voltage surge inputs, eliminating the need for external surge suppression devices, making it ideal for transportation, industrial and military applications.

Depending on the external components selected, the output voltage can be set from 1.2V to 150V and the output current can be as high as 10 amps. The LTC3779's powerful 1.3? N-channel MOSFET gate driver can be adjusted from 6V to 10V, allowing the use of logic levels or standard threshold MOSFETs. In high input voltage applications, to prevent significant power loss on the chip, the LTC3779 includes an NDRV pin that drives the gate of an optional external N-channel MOSFET that acts as a low dropout linear stability. The function of the voltage regulator is to provide an IC bias supply. The EXTVCC pin allows the LTC3779 to be powered with output or other available supplies up to 36V, reducing power consumption and increasing efficiency.

Up to 500W of output power can be delivered with a single device. Greater power can be provided when multiple circuits are configured in parallel. The operating frequency can be selected from 50kHz to 600kHz and can be synchronized to an external clock of the same range. The LTC3779 uses a proprietary current mode control architecture to achieve constant frequency operation in buck or boost mode. The user can choose to force continuous mode or discontinuous mode to maximize efficiency at light loads.

Other features include input or output average current limit, a power good output voltage monitor, adjustable soft start, and input overvoltage lockout and output voltage disconnect during shutdown. The LTC3779 is available in a 38-lead TSSOP package that provides additional pin spacing for high voltage operation. The device is available in two operating junction temperature versions, with extended and industrial temperature versions operating from -40°C to 125°C, and high temperature automotive versions with operating junction temperatures ranging from –40°C to 150°C. The starting price for a 1,000-piece lot is $5.95 per piece. For more information, please log in

LTC3779.

Performance Summary: LTC3779                          

?    4 Switch Single Inductor Synchronous Buck-Boost Architecture

?    Operates with an input voltage above, below or equal to the output voltage

?    4.5V to 150V input voltage range

?    1.2V to 150V output voltage range

?    Up to 99% efficiency

?    Built-in LDO or external NMOS LDO for DRVCC

?    36V EXT V CC LDO powering the drive

?    Input or output average current limit

?    Adjustable 6V to 10V MOSFET Gate Driver

?    Compatible with logic levels or standard threshold NMOS

?    A single device can deliver 500W of output power

?    50kHz to 600kHz fixed synchronous operating frequency

?    Output voltage disconnected during shutdown

?    Adjustable soft start

?    Reference voltage accuracy is ±1% over the –40oC to 150oC temperature range

?    TSSOP-38 package with extra lead spacing

The quotes given in this article are for budgetary purposes only. Quotations around the country may vary depending on local tariffs, taxes, fees and exchange rates.