LT1725 - General Purpose Isolated Flyback Controller

The LT1725 has a number of features not found on most other switching regulator ICs. By utilizing current mode switching techniques, it provides excellent AC and DC line regulation. Its unique control circuitry can maintain regulation well into discontinuous mode in most applications. Optional load compensation circuitry allows for improved load regulation. An optional undervoltage lockout pin halts operation when the application input voltage is too low. An optional external capacitor implements a soft-start function. A 3V output is available at up to several mA for powering primary side application circuitry.

特点
  • Drives External Power MOSFET with External ISENSE Resistor
  • Application Input Voltage Limited Only by External Power Components
  • Senses Output Voltage Directly from Primary Side Winding—No Optoisolator Required
  • Accurate Regulation Without User Trims
  • Regulation Maintained Well into Discontinuous Mode
  • Switching Frequency from 50kHz to 250kHz with External Capacitor
  • Available in 16-Pin SO and SSOP Packages
  • Optional Load Compensation
  • Optional Undervoltage Lockout
典型应用
LT1725 Typical Application
LT1725 Typical Application
应用
  • Telecom Isolated Converters
  • Offline Isolated Power Supplies
  • Instrumentation Power Supplies
封装信息
LT1725 Package Drawing
Order Information 订购型号
器件型号封装温度价格 (以 1 ~ 99 片为批量)价格 (以 1000 片为批量) *
LT1725CGN#PBFSSOP-16C$3.55$3.00
LT1725CGN#TRPBFSSOP-16C$3.06
LT1725CS#PBFSO-16C$3.43$2.90
LT1725CS#TRPBFSO-16C$2.96
LT1725IGN#PBFSSOP-16I$4.14$3.50
LT1725IGN#TRPBFSSOP-16I$3.56
LT1725IS#PBFSO-16I$4.03$3.40
LT1725IS#TRPBFSO-16I$3.46
演示电路板
器件型号描述价格
DC373A-ALT1725IGN | 48Vin to 5Vout 2A Module, Isolated Flyback, 1x2 Footprint$150.00
DC373A-BLT1725IGN | 48Vin to 3.3V/3A, 10W Module, Isolated Flyback, 1x2 Footprint$150.00
DC431ALT1725CGN LTC1773EMS | Telecom Input, Isolated 3 Output DC/DC Converter, +36V to +72V Input, Vout = 5V/1A, 3.3V/5A, 2.5V/4A联系凌力尔特
DC508ALT1725CGN | Low Cost, High Efficiency Synchronous Forward Converter w/o Optoisolator, +Vin = 36V-72V, +Vout = 2.5V/3.3V at 10A联系凌力尔特
DC562A-ALT1725CGN | Isolated Forward Converter, Vin=36V to 72V, Vout=3.3V@30A联系凌力尔特
DC562A-BLT1725CGN | Isolated Forward Converter, Vin=36V to 72V, Vout=5V@20A联系凌力尔特
DC562A-CLT1725CGN | Isolated Forward Converter, Vin=36V to 72V, Vout=12V@12A联系凌力尔特
DC638ALT1725CGN | Synchronous Flyback Converter, 36V - 72Vin, to 3.3V @ 3.5A, 350mA Input Current联系凌力尔特
数据表
设计要点
可靠性数据
LT Journal
CAD 符号
相关产品
LT1725 - General Purpose Isolated Flyback Controller
DN260 - Isolated Flyback Converter Regulates Without an Optocoupler
DN338 - Power over Ethernet Isolated Power Supply Delivers 11.5W at 90% Efficiency
R387 Reliability Data
May 2002 Simple Isolated Telecom Flyback Circuit Provides Regulation Without Optocoupler
LT1725 Footprints and Symbols