LTC781x Synchronous Boost Buck Controllers Analog Devices Inc. LTC781x Synchronous Boost Buck Controllers are high-performance, low quiescent current 38V and 60V DC-DC switching regulator controllers. The LTC781x Controllers drive the N-channel power MOSFET stages. The design includes independent step-up (boost) and step-down (buck) controllers. These independent boost and buck controllers can regulate two separate outputs. When cascaded, the independent boost and buck controllers regulate the output voltage from the input voltage. The input voltage can be above, below, or equal to the output voltage.