Analog Devices LTC3643

Description

The LTC®3643 is a bidirectional synchronous stepupcharger and step-down converter which efficientlycharges a capacitor array up to 40V from an input supplybetween 3V to 17V. When the input supply falls below theprogrammable power-fail threshold, the step-up chargeroperates in reverse as a synchronous step-down regulatorto power the system rail from the backup capacitor duringthis power interruption/failure condition.When charging the backup capacitor, an external lowvaluesense resistor may be used to maintain an accuratecurrent limit from the input supply or implementPowerPath™ functionality.The step-down converter operates at a 1MHz switchingfrequency, allowing small external components to beused. Low quiescent current during regulation maximizesthe energy usage from the backup capacitor.

Features

Bidirectional Synchronous Boost CapacitorCharger/Buck Regulator for System Backupnn Wide Input Voltage Range: 3V to 17Vnn Up to 40V Capacitor Voltage Storage for HighEnergy Backupnn 2A Maximum CAP Charge Currentnn Integrated Power N-Channel MOSFETs(150mΩ Top and 75mΩ Bottom)nn Integrated Power N-Channel MOSFET for Output/CAPDisconnect (50mΩ)nn Input Current Limit During Chargingnn Fast 1MHz Switching Frequencynn ±1% Reference Accuracy for System Voltage Regulationnn Indicator Outputs for Charge Status and Input Power Failnn Low Profile 24-lead 3mm × 5mm QFN Package

Typical applications

• Solid-State Drives
• Backup Capacitor Systems, Power Failure Backup Systems,

More information

• Datasheet
• IC product information