Hybrid step-down DC-DC controller reduces solution size by 50%

Analog Devices has released the Power by Linear LTC7821, a hybrid step-down synchronous controller that blends a switched capacitor circuit with a synchronous step-down controller, facilitating up to a 50% reduction in DC-DC converter solution size compared to traditional step-down solutions. This improvement is enabled by three times higher switching frequency without jeopardizing efficiency. Alternatively, when performing at the same frequency, an LTC7821-based solution offers up to 3% higher efficiency. Other benefits include low EMI and reduced MOSFET stress due to a soft-switched front end, ideal for next-generation non-isolated intermediate bus applications in power distribution, datacom and telecom as well as emerging 48V automotive systems. The device implements many exclusive protection features for robust performance in a wide range of applications. An LTC7821-based design removes the inrush current typically associated with switched capacitor circuits by pre-balancing the capacitors during start-up. The device also monitors current, system voltage and temperature for faults, and uses a sense resistor for overcurrent protection. It stops switching and pulls the /FAULT pin low when a fault condition happens. An onboard timer can be set for appropriate restart/retry times. The EXTVCC pin enables the device to be powered from the lower voltage output of the converter or another available source up to 40V, reducing power dissipation and improving efficiency.