Synchronous buck-boost controller eliminates surge protection devices

Linear Technology offers the LTC3779, a high efficiency (up to 99%) four-switch single inductor synchronous buck-boost DC-DC controller that operates from input voltages above, below or equal to the regulated output voltage. Its 4.5V to 150V input voltage range is designed to operate from a high input voltage source or from an input that has high voltage surges, eliminating the need for external surge suppression devices, ideal for transportation, industrial and military applications. The output voltage can be set from 1.2V to 150V at output currents up to 10s of amps, depending on the choice of external components. The device’s powerful 1.3ohm N-channel MOSFET gate drivers can be adjusted from 6V to 10V, enabling the use of logic-level or standard threshold MOSFETs. To prevent high on-chip power dissipation in high input voltage applications, the LTC3779 includes an NDRV pin which drives the gate of an optional external N-channel MOSFET acting as a low dropout linear regulator to supply IC bias power. The EXTVcc pin permits the device to be powered from the output or other available source up to 36V, reducing power dissipation and improving efficiency.