2A Bidirectional Power Backup Supply

The LTC3643 is a bidirectional synchronous step-up charger and step-down converter which efficiently charges a capacitor array up to 40V from an input supply between 3V to 17V. When the input supply falls below the programmable power-fail threshold, the step-up charger operates in reverse as a synchronous step-down regulator to power the system rail from the backup capacitor during this power interuption/failure condition.

When charging the backup capacitor, an external low-value sense resistor may be used to maintain an accurate current limit from the input supply or implement PowerPath™ functionality.

The step-down converter operates at a 1MHz switching frequency, allowing small external components to be used. Low quiescent current during regulation maximizes the energy usage from the backup capacitor.

Applications

* Backup Capacitor Systems

* Power Failure Backup Systems

* Solid-State Drives

* Automotive

* Bidirectional Synchronous Boost Capacitor Charger/Buck Regulator for System Backup* Wide Input Voltage Range: 3V to 17V* Up to 40V Capacitor Voltage Storage for High Energy Backup* 2A Maximum CAP Charge Current* Integrated Power N-Channel MOSFETs (150mΩ Top and 75mΩ Bottom)* Integrated Power N-Channel MOSFET for Output/CAP Disconnect (50mΩ)