LTC3351

LTC3351 Hot Swappable Supercapacitor Charger, Backup Controller and System Monitor FEATURES n Integrated Hot Swap Controller with Circuit Breaker n High Efficiency Synchronous Step-Down CC/CV Charging of One to Four Series Supercapacitors n Step-Up Mode in Backup Provides Greater Utilization of Stored Energy in Supercapacitors n 16-Bit ADC for Monitoring System Voltages/ Currents, Capacitance and ESR n Programmable Undervoltage and Overvoltage Thresholds to 35V n VIN: 4.5V to 35V, VCAP(n): Up to 5V per Capacitor, Charge/Backup Current: >10A n Programmable Input Current Limit Prioritizes System Load Over Capacitor Charge Current n All N-FET Charger Controller and PowerPath™ Controller n Compact 44-Lead 4mm × 7mm QFN Package APPLICATIONS n Swappable PCIE Cards with NVM n High Current 12V Ride-Through UPS n Servers/Mass Storage/High Availability Systems DESCRIPTION The LTC®3351 is a backup power controller that charges and monitors a series stack of one to four supercapacitors. The LTC3351’s synchronous step-down controller drives N-channel MOSFETs for constant current/constant voltage charging with programmable input current limit. In addition, the step-down converter runs in reverse as a step-up converter to deliver power from the supercapacitor stack to the backup supply rail. Internal balancers eliminate the need for external balance resistors and each capacitor has a shunt regulator for overvoltage protection. The LTC3351 monitors system voltages, currents, stack capacita...