MAXIM MAX38886ATD+

The MAX38886 is a storage capacitor or capacitor bank backup regulator designed to efficiently transfer power between a storage element and a system supply rail in reversible buck and boost operations using the same inductor. When the main supply is present and above the minimum system supply voltage, the regulator operates in buck mode and charges the storage element at up to 500mA peak inductor current. Once the storage element is charged, the circuit draws only 2.5μA of current while it maintains the supercapacitor or other storage element in its ready state. 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 at up to 2.5A peak inductor current. The MAX38886 is externally programmable for minimum and maximum voltage of the storage element, such as supercapacitor, minimum system voltage, and maximum charge and discharge currents. The internal DC-DC converter requires only a 1μH inductor.

The MAX38886 is a flexible storage capacitor or capacitor bank backup regulator that efficiently transfers power between a storage element and a system supply rail. When the main supply is present and its voltage above the minimum system supply voltage, the regulator operates in the charging mode of operation and charges the storage element at up to 500mA peak inductor current. When the main supply is removed, the regulator prevents the system from dropping below the minimum operating voltage, boosting VSYS by discharging the storage element at up to 2.5A peak inductor current. For backup mode functioning, ensure that the supercapacitor is charged up to 2.7V. During this backup mode of operation, the MAX38886 utilizes a fixed on-time, current-limited, pulse-frequency-modulation (PFM) control scheme. When VSYS is applied for the first time, ensure that the supercapacitor is charged to 2.7V to activate backup mode. The external pins allow a wide range of system and storage element, such as supercapacitor voltage settings, as well as charging and discharging peak inductor current settings.

• 2.5V to 5V System Output Voltage
• Up to 4.5V Capacitor Voltage Range
• Up to 2.5A Peak Inductor Discharge Current
• Programmable Voltage and Current Thresholds
• ±2% Threshold Accuracy
• Up to 95% Efficiency, Charge or Discharge
• 2.5μA Ready Quiescent Current
• Small Solution Size
• 3mm x 3mm x 0.75mm TDFN Package

• Handheld Industrial Equipment
• Portable Computers
• Portable Devices with a Removable Battery