MAX38888 Reversible Buck/Boost Regulator for Backup Power Applications

Analog Devices' MAX38888 is a capacitor bank or storage capacitor backup regulator. The regulator is designed to efficiently transfer power between a storage capacitor and a system supply rail in reversible buck and boost operations while using the same inductor.

The MAX38888ATD+ works by monitoring the main power supply and if above the minimum system supply voltage, the regulator operates in buck mode and charges the storage element at up to 500 mA peak inductor current. When the main supply is removed, the regulator operates in boost mode and prevents the system from dropping below the minimum operating voltage, discharging the storage element up to 2.5 A peak inductor current. When the storage element is charged, the circuit draws only 2.5 µA of current while it maintains the supercapacitor in its ready state.

The MAX38888ATD+ is externally programmable for minimum and maximum voltage of the supercapacitor, minimum system voltage, and maximum charge and discharge currents.