Single Inductor, High Rel Synchronous Buck-Boost Controller

Linear Technology Corporation announces a new high reliability (MP) grade version of the LTC3780, a very high efficiency synchronous buck-boost switching regulator dc-dc controller that operates from input voltages above, below or equal to the output voltage. High power buck-boost circuits typically rely on transformers or two DC/DC converters, one for step-up (boost) and the other for step-down (buck) conversion. The LTC3780MP operates using a single inductor and can deliver output power up to 150W with a single device. Higher power can be achieved when multiple circuits are paralleled. With 4-switch synchronous rectification, it can deliver efficiencies up to 98%.

The LTC3780MP operates with a selectable fixed frequency between 200kHz and 400kHz, and can be synchronized to an external clock over the same range with its phased-locked loop (PLL). Its wide 4V to 36V input range, 0.8V to 30V output range and seamless transitions between operating modes make it ideal for military, automotive and battery-powered systems. The LTC3780MP employs a proprietary current control architecture for constant frequency operation in buck or boost mode and has powerful on-board MOSFET gate drivers. Fault protection is provided for overvoltage, overcurrent and short circuit conditions in all operating modes. The output voltage turn-on time can be adjusted with the device's programmable soft-start. A power good output signals whether the output voltage is within regulation. The user can select from continuous operation, pulse skipping and Burst Mode® operation during light loads, which safely powers pre-biased loads.

The LTC3780MP operates and is 100% tested over an operating junction temperature range of -55°C to 125°C and is offered in a 24-lead SSOP package. 1,000-piece pricing starts at $7.24 each.