LTC3541-1 High Efficiency Buck + VLDO Regulator

The LTC3541-1 combines a synchronous buck DC/ DC converter with a very low dropout linear regulator (VLDO) to provide up to two output voltages from a single input voltage with minimal external components. When configured for dual output operation, the LTC3541-1’s auto start-up feature will bring the VLDO/linear regulator output into regulation in a controlled manner prior to enabling the Buck regulator output without the need for external pin control. Buck output prior to VLDO/linear regulator output sequencing may also be obtained via external pin control. The input voltage range is ideally suited for Li-Ion batterypowered applications, as well as powering sub-3.3V logic from 5V or 3.3V rails.

The synchronous buck converter provides a high efficiency output, typically 90%, capable of providing up to 500mA of continuous output current while switching at 2.25MHz, allowing the use of small surface mount inductors and capacitors. A mode-select pin allows Burst Mode operation to be enabled for higher efficiency at light load currents, or disabled for lower noise, constant frequency operation.

The VLDO regulator provides a low noise, low voltage output capable of providing up to 300mA of continuous output current using only a 2.2µF ceramic capacitor. The input supply voltage of the VLDO regulator (LVIN) may come from the buck regulator or a separate supply

产品特点 Features
  • High Efficiency, 500mA Buck Plus 300mA VLDOTM Regulator
    Auto Start-Up Powers VLDO/linear Regulator
    Output Prior to Buck Regulator Output
  • Independent High Effi ciency, 500mA Buck (VIN: 2.7V to 5.5V)
  • 300mA VLDO Regulator with 30mA Standalone Mode
  • No External Schottky Diodes Required
  • Buck Output Voltage Range: 0.8V to 5V
  • VLDO Input Voltage Range (LVIN): 0.9V to 5.5V
  • VLDO Output Voltage Range VLDO: 0.4V to 4.1V
  • Selectable Fixed Frequency, Pulse-Skip Operation or Burst Mode® Operation
  • Short-Circuit Protected
  • Current Mode Operation for Excellent Line and Load Transient Response
  • Constant Frequency Operation: 2.25MHz
  • Low Dropout Buck Operation: 100% Duty Cycle
  • Small, Thermally Enhanced, 10-Lead (3mm × 3mm) DFN Package
应用
  • PDAs/Palmtop PCs
  • Digital Cameras
  • Cellular Phones
  • PC Cards
  • Wireless and DSL Modems
  • Other Portable Power Systems
典型应用图
LTC3541-1 典型应用
参数
LTC3541-1 参数
LTC3541-1 订购信息和价格参考Package Variations and Pricing
器件型号 封装 引脚 温度 价格 (以 1 ~ 99 片为批量) 价格 (以 1000 片为批量) *
LTC3541EDD#PBF DFN 10 E $2.70  $1.89 
LTC3541EDD#TRPBF DFN 10 E $1.95 
LTC3541EDD-1#PBF DFN 10 E $2.70  $1.89 
LTC3541EDD-1#TRPBF DFN 10 E $1.95 
LTC3541EDD-2#PBF DFN 10 E $2.70  $1.89 
LTC3541EDD-2#TRPBF DFN 10 E $1.95 
LTC3541EDD-3#PBF DFN 10 E $2.70  $1.89 
LTC3541EDD-3#TRPBF DFN 10 E $1.95 
LTC3541-1 数据手册及相关资料下载
  1. 数据手册(英文) : LTC3541-1 - High Efficiency Buck + VLDO Regulator.PDF
  2. 产品选型卡 : Energy Harvesting Portfolio.PDF
  3. 可靠性数据 : R415 Reliability Data .PDF