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AC-DC Synchronous
Rectifier IC Driver, IR1168S
The IR1168S is a dual smart secondary-side rectifier
driver IC designed to drive two N-Channel power
MOSFETs used as synchronous rectifiers in resonant
converter applications. The IC can control one or more
paralleled N MOSFETs to emulate the behavior of
Schottky diode rectifiers. The drain-to-source voltage for
each rectifier MOSFET is sensed differentially to
determine the level of the current and the power switch is
turned ON and OFF in close proximity of the zero current
transition.
Features
• Secondary-side high speed controller for
synchronous rectification in resonant halfbridge topologies
• 200V proprietary IC technology
• Max 500 kHz switching frequency
• Anti-bounce logic and UVLO protection
• 4A peak turn off drive current
• Microcontroller start-up and ultra low
quiescent current
• 10.7V gate drive clamp
• 70 ns turn-off propagation delay
• Wide VCC operating range
• Direct sensing for both synchronous
rectifiers
• Minimal component count
• Simple design
• Lead-free
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AC-DC HOME
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Advantages
• Ruggedness and noise immunity are accomplished using an
advanced blanking scheme and double-pulse suppression that
allows reliable operation in fixed and variable frequency
applications.
• Supply circuitry is not necessary because the supply comes from
the output voltage or from the winding from the transformer.
• The IR1168S is efficient even at light load because it is compatible
with the burst mode.
• The IR1168S senses the current across the MOSFET which
ensures accurate turn on and turn off.
• An IR1168S based solution shows an efficient improvement of a
standard 240W LCD TV SMPS by 1.5%%, together with a
reduction of rectifier devices by 25C.