Intermittent short-term power outages caused by local storms or other transient behavior can play havoc with computer-based systems. A power supply with ride-through capability provides power for a limited time during the outage. The LTC3350 announced recently by Linear Technology Corp is a high current backup controller and system monitor for power supplies using supercapacitors for ride-through energy storage.
It controls and balances the charge stored on up to four series connected supercapacitors and can handle 4.5V to 35V input voltage and over 10A of charge/backup current. A 14-bit analog-to-digital converter monitors both the input and output voltage and current. The chip uses a synchronous step-down controller to drive external N-channel MOSFETs for constant current/voltage charging of the capacitor stack allowing up to 5 V per cell. When backup is needed the step-down converter operates in reverse as a synchronous step-up DC/DC converter, drawing power from the supercapacitor stack to supply back-up power.
The device is designed for high current 12V ride-through supplies and short-term uninterruptible power supplies (UPS) for servers, mass storage and high availability systems. The LTC3350 is packaged in a thermally-enhanced 38-lead, low-profile (0.75 mm) 5 mm x 7 mm QFN outline.