LTC3643
2A Bidirectional
Power Backup Supply
FEATURES DESCRIPTION Bidirectional Synchronous Boost Capacitor
Charger/Buck Regulator for System Backup
nn Wide Input Voltage Range: 3V to 17V
nn Up to 40V Capacitor Voltage Storage for High
Energy Backup
nn 2A Maximum CAP Charge Current
nn Integrated Power N-Channel MOSFETs
(150mО© Top and 75mО© Bottom)
nn Integrated Power N-Channel MOSFET for Output/CAP
Disconnect (50mО©)
nn Input Current Limit During Charging
nn Fast 1MHz Switching Frequency
nn В±1% Reference Accuracy for System Voltage Regulation
nn Indicator Outputs for Charge Status and Input Power Fail
nn Low Profile 24-lead 3mm Г— 5mm QFN Package The LTCВ®3643 is a bidirectional synchronous stepup 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 …