ON Semiconductor

Secondary Side Synchronous Rectification Driver for High Efficiency SMPS Topologies

Secondary Side Synchronous Rectification Driver for High Efficiency SMPS Topologies

The NCP4308 is a synchronous rectifier controller for switch modepower supplies. The controller enables high efficiency designs forflyback, quasi resonant flyback and LLC topologies.Externally adjustable minimum off−time and on−time blankingperiods provides flexibility to drive various MOSFET package typesand PCB layout. A reliable and noise less operation of the SR system isinsured due to the Self Synchronization feature. The NCP4308 alsoutilizes Kelvin connection of the driver to the MOSFET to achieve highefficiency operation at full load.The precise turn−off threshold, extremely low turn−off delay timeand high sink current capability of the driver allow the maximumsynchronous rectification MOSFET conduction time. The highaccuracy driver and 5 V gate clamp make it ideally suited for directlydriving GaN devices.To provide more flexibility in PCB layout there are two versions of this product.NCP4308 does NOT have LLD functionNCP43080 has LLD function

The NCP43080 is a synchronous rectifier controller for switch modepower supplies. The controller enables high efficiency designs forflyback, quasi resonant flyback and LLC topologies.Externally adjustable minimum off−time and on−time blankingperiods provides flexibility to drive various MOSFET package typesand PCB layout. A reliable and noise less operation of the SR system isinsured due to the Self Synchronization feature. The NCP4308 alsoutilizes Kelvin connection of the driver to the MOSFET to achieve highefficiency operation at full load.The precise turn−off threshold, extremely low turn−off delay timeand high sink current capability of the driver allow the maximumsynchronous rectification MOSFET conduction time. The highaccuracy driver and 5 V gate clamp make it ideally suited for directlydriving GaN devices.To provide more flexibility in PCB layout there are two versions of this product.NCP4308 does NOT have LLD functionNCP43080 has LLD function

The NCP431 integrated circuits are three-terminal programmable shunt regulator diodes. They are a direct upgrade to the industry standard TL431A. These monolithic IC voltage references operate as a low temperature coefficient zener which is programmable from Vref to 36 V using two external resistors. These devices exhibit a wide operating current range of 40 µA to 100 mA with a typical dynamic impedance of 0.22Ω. The characteristics of these references make them excellent replacements for zener diodes in many applications such as digital voltmeters, power supplies, and op amp circuitry. The 2.5 V reference makes it convenient to obtain a stable reference from 5.0 V logic supplies, and since the NCP431 operates as a shunt regulator, it can be used as either a positive or negative voltage reference. Low minimum operating current makes this device an ideal choise for secondary regulators in SMPS adapters with extremely low no-load consumption.The NCP432 has exactly the same functionality and electrical specifications as the NCP431, but has an alternate pin configuration.

NCP4318 is a mixed mode, which uses instantaneous drain voltage and previous dead time information, Synchronous Rectification (SR) controller for LLC resonant converter with minimum external components. The adaptive dead time control compensates induced parasitic inductance voltage to maximize SR MOSFET conduction and the efficiency. Multi-step turn-off threshold control and SR current inversion detection function prevent inversion current during fast load transient and allows stable SR operation over entire load range. In addition, to improve light load efficiency, VGATE is adaptively reduced from 10V to 6V/5V.

The NCP4330 houses a dual MOSFET driver intended to be used as a companion chip in AC−DC or DC−DC multi−output post regulated power supplies. Being directly fed by the secondary AC signal, the device keeps power dissipation to the lowest while reducing the surrounding part count. Furthermore, the implementation of a N−channel MOSFET gives NCP4330−based applications a significant advantage in terms of efficiency.