LTC3900 - Synchronous Rectifier Driver for Forward Converters

The LTC®3900 is a secondary-side synchronous rectifier driver designed to be used in isolated forward converter power supplies. The chip drives N-channel rectifier MOSFETs and accepts pulse sychronization from the primary-side controller via a pulse transformer.

The LTC3900 incorporates a full range of protection for the external MOSFETs. A programmable timeout function is included that disables both drivers when the synchronization signal is missing or incorrect. Additionally, the chip senses the output inductor current through the drainsource resistance of the catch MOSFET, shutting off the MOSFET if the inductor current reverses. The LTC3900 also shuts off the drivers if the supply voltage is too low.

Features
  • N-Channel Synchronous Rectifier MOSFET Driver
  • Programmable Timeout Protection
  • Reverse Inductor Current Protection
  • Pulse Transformer Synchronization
  • Wide VCC Supply Range: 4.5V to 11V
  • 15ns Rise/Fall Times at VCC = 5V, CL = 4700pF
  • Undervoltage Lockout
  • Small SO-8 Package
Typical Application
LTC3900 Typical Application
LTC3900 Typical Application
Applications
  • 48V Input Isolated DC/DC Converters
  • Isolated Telecom Power Supplies
  • High Voltage Distributed Power
  • Industrial Control System Power Supplies
  • Automotive and Heavy Equipment
Packaging
LTC3900 Package Drawing
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LTC3900ES8#PBFSO-8E$3.57$2.50
LTC3900ES8#TRPBFSO-8E$2.56
LTC3900HS8#PBFSO-8H$4.11$2.88
LTC3900HS8#TRPBFSO-8H$2.94
LTC3900IS8#PBFSO-8I$3.70$2.59
LTC3900IS8#TRPBFSO-8I$2.65
LTC3900MPS8#PBFSO-8MP$10.00$7.00
LTC3900MPS8#TRPBFSO-8MP$7.06
Demo Boards
Part NumberDescriptionPrice
DC1317A-CLT1952EGN-1/LTC3900 Demo Board | Active Reset, Vin=18V-72V Vout=12V @ 10A$175.00
DC1317A-GLT1952EGN-1/LTC3900 Demo Board | Active Reset, Vin=9V-36V Vout=12V @ 5A$175.00
DC677ALT1952-1EGN-1, LTC3900ES Demo Board | Vin=36V-75V, Vout=3.3V @ 50AContact Factory
DC968A-ALT1952EGN-1, LTC3900CS8, LT4430ES6 Demo Board | Vin=34V-75V Vout=3.3V @ 30A$150.00
DC968A-BLT1952EGN-1, LTC3900CS8, LT4430ES6 Demo Board | Vin=18V-36V, Vout=5V @ 20A$175.00
DC968A-CLT1952EGN-1, LTC3900CS8, LT4430ES6 Demo Board | Vin=36V-75V, Vout=12V @ 12A$150.00
DC968A-DLT1952EGN-1, LTC3900CS8, LT4430ES6 Demo Board | Vin=36V-75V, Vout=28V @ 4A$175.00
Datasheet
Reliability Data
LT Journal
Press Release
CAD Symbol
LTspice
Related Products
LTC3900 - Synchronous Rectifier Driver for Forward Converters
隔离式正向转换器集成电路规定在 -55°C 至 125°C 的节温范围内工作
R368 Reliability Data
March 2005 - Efficient and Reliable Drive for Synchronous MOSFET Rectifiers
Isolated Forward Converter Integrated Circuits Specified over -55°C to 125°C Junction Temperature Range
LTC3900 Footprints and Symbols
LT1952/LTC3900 Demo Circuit - Synchronous Forward Converter (36-75V to 3.3V @ 20A)