LTC3351IUFF#PBF

LTC®3351 is a backup power controller that charges and monitors a series stack of one to four supercapacitors. This 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. This monitors system voltages, currents, stack capacitance, and ESR which can all be read over the I²C/SMBus port. The hot swap controller uses N-channel MOSFETs for inrush control and a low loss path from the input to the output. Application includes swappable PCIE Cards with NVM, high current 12V ride-through UPS, servers/mass storage/high availability systems.

• Input supply voltage range from 4.5 to 35V (TJ=25°C)
• Typical default VCAPFB-DAC setting is 1.012V (TJ=25°C, 1010b)
• Minimum regulated VCAP feedback voltage is 0.625V (zero scale (0000b), TJ=25°C)
• Typical charge pump output voltage is 5V (Relative to VCAP, 0V <lt/> VCAP <lt/> 20V, TJ=25°C)
• Regulated input current sense voltage range from 31.04 to 32.96mV (TJ=25°C)
• Integrated hot swap controller with circuit breaker
• Step-up mode in backup provides greater utilization of stored energy in supercapacitors
• Programmable undervoltage and overvoltage thresholds to 35V
• 44-lead plastic QFN package
• Temperature range from -40°C to 125°C

Notes

ADI products are only authorized (and sold) for use by the customer and are not to be resold or otherwise passed on to any third party