Typical Application Circuit for LTC3727EG-1 High Efficiency, 2-Phase Synchronous Step-Down Regulator. The LTC3727-1 is a high performance dual step-down switching regulator controllers that drive all N-channel synchronous power MOSFET stages. A constant frequency current mode architecture allows phase lockable frequency of up to 550kHz. Power loss and noise due to the ESR of the input capacitors are minimized by operating the two controller output stages out of phase