LTC3355 - 20V 1A Buck DC/DC with Integrated SCAP Charger and Backup Regulator

The LTC®3355 is a complete input power interrupt ridethrough DC/DC system. The part charges a supercapacitor while delivering load current to VOUT, and uses energy from the supercapacitor to provide continuous VOUT backup power when VIN power 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 VIN supply 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 VIN programmable current limits. The LTC3355 is available in a 20-lead 4mm × 4mm QFN surface mount package.

Features
  • VIN Voltage Range: 3V to 20V
  • VOUT Voltage 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 VIN Current Limit
  • Programmable Boost Current Limit
  • VIN Power Fail Indicator
  • VCAP Power Good Indicator
  • VOUT Power On Reset Output
  • Compact 20-Lead 4mm × 4mm QFN Package
Typical Application

Applications
  • Ride-Through “Dying Gasp” Supplies
  • Power Meters/Industrial Alarms/Solid State Drives
Packaging
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LTC3355EUF#PBF4x4 QFN-20E$4.64$3.25
LTC3355EUF#TRPBF4x4 QFN-20E$3.31
LTC3355IUF#PBF4x4 QFN-20I$5.14$3.60
LTC3355IUF#TRPBF4x4 QFN-20I$3.66
Demo Boards
Part NumberDescriptionPrice
DC2040ALTC3355EUF Demo Board | 12V to 4V/1A Buck Regulator + SCAP Charger & Backup Boost Regulator$150.00
Datasheet
Reliability Data
Press Release
Related Product
LTC3355 - 20V 1A Buck DC/DC with Integrated SCAP Charger and Backup Regulator
R526 - Reliability Data
完整的可穿越 DC/DC IC 从主输入或单个超级电容器后备电源提供不间断的 1A 输出电流
LTC3355 Footprints and Symbols