LTC3541-3 High Efficiency Buck + VLDO Regulator

The LTC3541-3 combines a synchronous buck DC/ DC converter with a very low dropout linear regulator (VLDOTM regulator) and internal feedback resistor networks to provide two output voltages from a single input voltage with minimum external components. When configured for dual output operation, the LTC3541-3’s auto start-up feature will bring the 1.575V VLDO/linear regulator output into regulation in a controlled manner prior to enabling the 1.8V buck output without the need for external pin control. The 300mA VLDO/linear regulator output will source only 30mA until the buck output achieves regulation. The input voltage range is ideally suited for applications powered from a Li-Ion battery and 5V or 3.3V rails.

The synchronous buck converter provides a high efficiency output, typically 90%. It can provide up to 500mA of 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 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 VLDO Regulator
  • Auto Start-Up Powers Buck Output Prior to VLDO/ linear Regulator Output
  • Independent 500mA High Efficiency Buck (VIN: 2.7V to 5.5V)
  • 300mA VLDO Regulator with 30mA Standalone Mode
  • No External Schottky Diodes Required
  • Fixed Buck Output Voltage: 1.875V
  • VLDO Input Voltage Range (LVIN: 1.6V to 5.5V)
  • Fixed VLDO Output Voltage: 1.5V
  • Selectable Fixed Frequency, Pulse-Skip Operation or Burst Mode Operation
  • Short-Circuit Protected
  • Current Mode Operation for Excellent Line and Load Transient Response
  • Shutdown Current: <3μA
  • Constant Frequency Operation: 2.25MHz
  • Low Dropout Buck Operation: 100% Duty Cycle
  • Small, Thermally Enhanced, 10-Lead (3mm × 3mm) DFN Package
应用
  • Digital Cameras
  • Cellular Phones
  • PC Cards
  • Wireless and DSL Modems
  • Other Portable Power Systems
典型应用图
LTC3541-3 典型应用
参数
LTC3541-3 参数
LTC3541-3 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 
LTC3541-3 数据手册及相关资料下载
  1. 数据手册(英文) : LTC3541-3 - 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