LT3512 - Monolithic High Voltage Isolated Flyback Converter

The LT3512 is a high voltage monolithic switching regulator specifically designed for the isolated flyback topology. No third winding or opto-isolator is required for regulation as the part senses output voltage directly from the primary-side flyback waveform. The device integrates a 420mA, 150V power switch, high voltage circuitry, and control into a high voltage 16-lead MSOP package with four leads removed.

The LT3512 operates from an input voltage range of 4.5V to 100V and delivers up to 4.5W of isolated output power. Two external resistors and the transformer turns ratio easily set the output voltage. Off-the-shelf transformers are available for several applications. The high level of integration and the use of boundary mode operation results in a simple, clean, tightly regulated application solution to the traditionally tough problem of isolated power delivery.

Features
  • 4.5V to 100V Input Voltage Range
  • Internal 420mA, 150V Power Switch
  • Boundary Mode Operation
  • No Transformer Third Winding or Opto-Isolator Required for Regulation
  • Improved Primary-Side Winding Feedback Load Regulation
  • VOUT Set with Two External Resistors
  • BIAS Pin for Internal Bias Supply and Power Switch Driver
  • No External Start-Up Resistor
  • 16-Lead MSOP Package
Typical Application
LT3512 Typical Application
LT3512 Typical Application
Applications
  • Isolated Telecom Power Supplies
  • Isolated Auxiliary/Housekeeping Power Supplies
  • Isolated Industrial, Automotive and Medical Power Supplies
Packaging
LT3512 Package Drawing
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LT3512EMS#PBFMS-16E$4.50$3.15
LT3512EMS#TRPBFMS-16E$3.21
LT3512HMS#PBFMS-16H$5.54$3.88
LT3512HMS#TRPBFMS-16H$3.94
LT3512IMS#PBFMS-16I$4.96$3.47
LT3512IMS#TRPBFMS-16I$3.53
LT3512MPMS#PBFMS-16MP$13.36$9.35
LT3512MPMS#TRPBFMS-16MP$9.41
Demo Boards
Part NumberDescriptionPrice
DC1803ALT3512EMS Demo Board | 36V to 75VIN, VOUT = 5V @ 500mA$150.00
Datasheet
Design Note
Reliability Data
Press Release
CAD Symbol
LTspice
Related Products
LT3512 - Monolithic High Voltage Isolated Flyback Converter
DN509 - 具 6V 至 100V 输入电压范围的微功率隔离反激式转换器
DN525 - 无需使用光耦合器的单片隔离型反激式转换器可提供通用型解决方案
高压隔离型单片反激式稳压器简化设计且无需光耦合器
无光耦合器的 100V 隔离型单片反激式稳压器在 -55°C 至 150°C 的结温范围内工作
DN509 - Micropower Isolated Flyback Converter with Input Voltage Range from 6V to 100V
DN525 - Monolithic No-Opto Isolated Flyback Converter Provides Versatile Solution
R530 - Reliability Data
High Voltage Isolated Monolithic Flyback Regulator Simplifies Design & Eliminates Optocoupler
No-Opto 100V Isolated Monolithic Flyback Regulator Operates over a -55°C to 150°C Junction Temperature Range (LT3512)
LT3512 Footprints and Symbols
LT3512 Demo Circuit - Monolithic High Voltage Isolated Flyback Converter (48V to 5V@0.5A)