35V Hot-Swappable Supercapacitor Backup Power Controller Provides Uninterruptible Power Supply, Protection, and Monitoring

Analog Devices, Inc. (ADI) today announced the LTC3351, Power by Linear ™, a supercapacitor charger and back-up power controller IC that includes hot-swap front-end protection and all necessary features to provide a complete, Independent, capacitor-based backup power solution. The LTC3351's integrated hot-swap controllers and circuit breakers feature an N-channel MOSFET that provides low-loss path from input to output and reduced inrush current through foldback current limit. The device provides a reliable short-term uninterruptible power supply in the event of a primary power failure, suitable for solid state drives (SSDs) and nonvolatile dual in-line memory modules (NVDIMMs) Data backup, power supplies for medical and industrial applications Fault alarms, and applications such as "dying gasp" power failure indicators. The LTC3351 provides PowerPath ™ control, capacitor stack charging and balancing, protection, and capacitor health monitoring. Other applications include high-current 12V ride-through and short-term uninterruptible power supplies (UPS) for servers, mass storage, and high availability systems.

The LTC3351 features 4.5V to 35V input voltage range and 10A charge / backup current capability. The device also provides balanced and overvoltage protection for a series stack of 1 to 4 supercapacitors. The LTC3351's synchronous step-down controller charges the capacitor stack at a constant current / constant voltage up to 5V per capacitor. In backup mode, the buck converter operates as a synchronous step-up DC / DC converter operating from the super capacitor stack to the backup power system. Hot-swap controllers provide programmable UV / OV thresholds, PCIe-compatible startup timing, and precision threshold / retry inputs.

The LTC3351 contains a precision 16-bit analog-to-digital converter (ADC) that continuously monitors the voltage and current of the inputs and outputs. In addition, the internal measurement system monitors backup capacitor-related parameters including capacitor stack voltage, capacitance, and stack ESR (equivalent series resistance) to ensure sufficient energy storage and supply during fallback mode. By monitoring the actual capacitance of the backup supercapacitor, the LTC3351 allows the system to minimize the capacitor voltage while maintaining the required back-up power, thereby extending the capacitor's useful life. All system parameters and fault conditions can be monitored via a 2-wire I2C interface and the alarm level can be set to alert the system of sudden changes in these measurement parameters.

About LTC33 series products

Author：Brittany Antonia （The author of article owns the copyright.）