LTC3355 Series

20V 1A Buck DC/DC with Integrated SCAP Charger and Backup Regulator

Catalog

20V 1A Buck DC/DC with Integrated SCAP Charger and Backup Regulator

Part	Output Type	Voltage - Output (Max)	Operating Temperature [Min]	Operating Temperature [Max]	Frequency - Switching	Function	Voltage - Output (Min/Fixed)	Voltage - Input (Min) [Min]	Voltage - Input (Max) [Max]	Topology	Current - Output	Supplier Device Package	Number of Outputs	Synchronous Rectifier	Output Configuration	Mounting Type	Package / Case
Analog Devices LTC3355IUF#PBF	Adjustable	5 V	-40 °C	125 ¯C	1 MHz	Step-Down	2.7 V	3 V	20 V	Buck	1 A	20-QFN (4x4)	1		Positive	Surface Mount	20-WFQFN Exposed Pad

Catalog

20V 1A Buck DC/DC with Integrated SCAP Charger and Backup Regulator

Key Features

• VINVoltage Range: 3V to 20V

• VOUTVoltage Range: 2.7V to 5V

• 1A Current Mode Buck Main Regulator

• 5A Boost Backup Regulator Powered from Single Supercapacitor

• Boost Regulator Operates Down to 0.5V for Maximum Utilization of Supercapacitor Energy

• Programmable Supercapacitor Charge Current to 1A with Overvoltage Protection

• Charger Supports Single Cell CC/CV Battery Charging

• Programmable VINCurrent Limit

• Programmable Boost Current Limit

• VINPower Fail Indicator

• VCAPPower Good Indicator

• VOUTPower On Reset Output

• Compact 20-Lead 4mm × 4mm QFN Package

Description

The LTC3355 is a complete input power interrupt ride-through DC/DC system. The part charges a supercapacitor while delivering load current to VOUT, and uses energy from the supercapacitor to provide continuous VOUTbackup power when VINpower is lost. The LTC3355 contains a nonsynchronous constant frequency current mode monolithic 1A buck switching regulator to provide a 2.7V to 5V regulated output voltage from an input supply of up to 20V.A 1A programmable CC/CV linear charger charges the supercapacitor from VOUT. When the VINsupply drops below the PFI threshold, the devices’s constant frequency nonsynchronous current mode 5A boost switching regulator delivers power from the supercapacitor to VOUT. A thermal regulation loop maximizes charge current while limiting the die temperature to 110°C. The IC has boost, charger and VINprogrammable current limits. The LTC3355 is available in a 20-lead 4mm × 4mm QFN surface mount package.ApplicationsRide-Through "Dying Gasp" SuppliesPower Meters/Industrial Alarms/Solid State Drives