Datasheet Linear Technology LTC4040EUFD#PBF

LTC4040
2.5A Battery Backup
Power Manager
Features Description Step-Up Backup Supply and Step-Down Battery
Charger
nn 6.5A Switches for 2.5A Backup from 3.2V Battery
nn Input Current Limit Prioritizes Load Over Charge
Current
nn Input Disconnect Switch Isolates Input During Backup
nn Automatic Seamless Switch-Over to Backup Mode
nn Input Power Loss Indicator
nn System Power Loss Indicator
nn Pin Selectable Battery: Li-Ion (3.95V/4.0V/4.05V/4.1V)
or LiFePO4 (3.45V/3.5V/3.55V/3.6V)
nn Optional OVP Circuitry Protects Device to >60V
nn Constant Frequency Operation
nn Low Profile (0.75mm) 24-Lead 4mm × 5mm QFN Package The LTC®4040 is a complete 3.5V to 5.5V supply rail battery backup system. It contains a high current step-up
DC/DC regulator to back up the supply from a single-cell
Li-Ion or LiFePO4 battery. When external power is available, the step-up regulator operates in reverse as a stepdown battery charger. nn The LTC4040’s adjustable input current limit function
reduces charge current to protect the main supply from
overload while an external disconnect switch isolates the
external supply during backup. When the input supply
drops below the adjustable PFI threshold, the 2.5A boost …