Datasheet Linear Technology LTC3900IS8#PBF — Datenblatt

LTC3900
Synchronous Rectifier Driver
for Forward Converters
Features n n n n n n n n Description 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 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 drain-source
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. Applications 48V Input Isolated DC/DC Converters Isolated Telecom Power Supplies
n High Voltage Distributed Power
Step-Down Converters
n Industrial Control System Power Supplies …