Describes the LT3663 high-voltage, high-frequency, high-efficiency supercapacitor charger circuit, which is suitable for large-capacity (tens to hundreds of farads) supercapacitor applications and can power solid state RAID disks and other applications when power is lost.
The document details an application for the LT3663, a 1.2A, 1.5MHz step-down switching regulator with adjustable output voltage and current limit, specifically designed for charging larger value supercapacitors (tens to hundreds of farads). The circuit minimizes recharge time for energy hold-up devices in solid state RAID disks.
The note explains how to select the supercapacitor size based on power ride-through requirements and calculates the necessary recharge current. It further describes a control circuit that balances voltages across multiple series-connected supercapacitors, ensuring efficient charging even when components are mismatched.
The LT3663 has an output current limit of 1.2A.
The part has an input voltage range of 7.5V to 36V.