LTC7821 Hybrid Controllers pre-balance the capacitors during start-up to eliminate the inrush current typically associated with switched capacitor circuits. The controllers also monitor system voltage, current, and temperature for faults. A sense resistor provides overcurrent protection. When a fault condition occurs, LTC7821 stops switching and pulls the /FAULT pin. The EXTVCC pin enables the LTC7821 to be powered from the lower voltage output of the converter or other available sources up to 40V. This reduces power dissipation and improves efficiency.