LTC1698 - Isolated Secondary Synchronous Rectifier Controller

The LTC®1698 is a precision secondary-side forward converter controller that synchronously drives external N-channel MOSFETs. It is designed for use with the LT®3781 primary-side synchronous forward converter controller to create a completely isolated power supply. The LT3781 synchronizes the LTC1698 through a small pulse transformer and the LTC1698 drives a feedback optocoupler to close the feedback loop. Output accuracy of ±0.8% and high efficiency over a wide range of load currents are obtained.

The LTC1698 provides accurate secondary-side current limit using an external current sense resistor. The input voltage at the MARGIN pin provides ±5% output voltage adjustment. A power good flag and overvoltage input are provided to ensure proper power supply conditions. An auxiliary 3.3V logic supply is included that supplies up to 10mA of output current.

特点
  • High Efficiency Over Wide Load Current Range
  • ±0.8% Output Voltage Accuracy
  • Dual N-Channel MOSFET Synchronous Drivers
  • Pulse Transformer Synchronization
  • Optocoupler Feedback Driver
  • Programmable Current Limit Protection
  • ±5% Margin Output Voltage Adjustment
  • Adjustable Overvoltage Fault Protection
  • Power Good Flag
  • Auxiliary 3.3V Logic Supply
  • Available in 16-Lead SSOP and SO Packages
典型应用
LTC1698 Typical Application
应用
  • 48V Input Isolated DC/DC Converters
  • Isolated Telecommunication Power Systems
  • Distributed Power Step-Down Converters
  • Industrial Control Systems
  • Automotive and Heavy Equipment
封装信息
LTC1698 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) *
LTC1698EGN#PBFSSOP-16E$6.27$5.30
LTC1698EGN#TRPBFSSOP-16E$5.36
LTC1698ES#PBFSO-16E$6.33$5.35
LTC1698ES#TRPBFSO-16E$5.41
LTC1698IGN#PBFSSOP-16I$6.92$5.85
LTC1698IGN#TRPBFSSOP-16I$5.91
LTC1698IS#PBFSO-16I$6.98$5.90
LTC1698IS#TRPBFSO-16I$5.96
演示电路板
器件型号描述价格
DC479ALT3781EG, LTC1698EGN, LT1783CS5 | Isolated Synchronous, Forward Converter, Vin=36V-72V, Vout=3.3V @ 15A$75.00
DC617ALT3781EG LTC1698EGN LT1783CS5 | Isolated Synchronous Forward Converter, +Vin = 36V - 72V, +Vout = 2.5V @ 20A, Quarter Brick footprint$75.00
DC759ALT1952EGN, LTC1698EGN | 48Vin to 5V at 20A Converter, +Vin = 36V - 72V, +Vout = +5V at 20A$175.00
数据表
设计要点
可靠性数据
CAD 符号
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LTC1698 - Isolated Secondary Synchronous Rectifier Controller
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R245 Reliability Data
LTC1698 Footprints and Symbols