LTC3643 Series

2A Bidirectional Power Backup Supply

Catalog

2A Bidirectional Power Backup Supply

Part	Supplier Device Package	Number of Outputs	Topology	Function	Output Type	Package / Case	Current - Output	Output Configuration	Voltage - Input (Max) [Max]	Voltage - Input (Min) [Min]	Mounting Type	Frequency - Switching	Operating Temperature [Min]	Operating Temperature [Max]	Voltage - Output (Min/Fixed)
Analog Devices LTC3643IUDD#TRPBF	24-QFN (3x5)	1	Boost Buck	Step-Down Step-Up	Adjustable	24-WFQFN Exposed Pad	2 A	Positive	17 V	3 V	Surface Mount	1 MHz	-40 °C	125 ¯C	0.6 V
Analog Devices LTC3643IUDD	24-QFN (3x5)	1	Boost Buck	Step-Down Step-Up	Adjustable	24-WFQFN Exposed Pad	2 A	Positive	17 V	3 V	Surface Mount	1 MHz	-40 °C	125 ¯C	0.6 V
Analog Devices LTC3643EUDD#TRPBF	24-QFN (3x5)	1	Boost Buck	Step-Down Step-Up	Adjustable	24-WFQFN Exposed Pad	2 A	Positive	17 V	3 V	Surface Mount	1 MHz	-40 °C	125 ¯C	0.6 V

Catalog

2A Bidirectional Power Backup Supply

Key Features

• Bidirectional Synchronous Boost Capacitor Charger/Buck Regulator for System Backup

• Wide Input Voltage Range: 3V to 17V

• Up to 40V Capacitor Voltage Storage for High Energy Backup

• 2A Maximum CAP Charge Current

• Integrated Power N-Channel MOSFETs (150mΩ Top and 75mΩ Bottom)

• Integrated Power N-Channel MOSFET for Output/CAP Disconnect (50mΩ)

• Input Current Limit During Charging

• Fast 1MHz Switching Frequency

• ±1% Reference Accuracy for System Voltage Regulation

• Indicator Outputs for Charge Status and Input Power Fail

• Low Profile 24-lead 3mm × 5mm QFN Package

Description

The LTC3643 is a bidirectional synchronous step-up 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 this power interuption/failure condition.When charging the backup capacitor, an external low-value sense resistor may be used to maintain an accurate current limit from the input supply or implement PowerPath™functionality.The step-down converter operates at a 1MHz switching frequency, allowing small external components to be used. Low quiescent current during regulation maximizes the energy usage from the backup capacitor.ApplicationsBackup Capacitor SystemsPower Failure Backup SystemsSolid-State Drives