Description The TOPSwitch family implements, with only three terminals,all functions necessary for a DC to DC, converter: high voltageN-channel power MOSFET with controlled turn-on gate driver,voltage mode PWM controller with integrated 120 kHz oscillator,high voltage start-up bias circuit, bandgap derived reference,bias shunt regulator/error amplifier for loop compensation andfault protection circuitry. Compared to discrete MOSFET andcontroller or self oscillating (RCC) switching converter solutions,a TOPSwitch integrated circuit can reduce total cost, componentcount, size, weight and at the same time increase efficiency andsystem reliability. This device is well suited for Telecom,Cablecom and other DC to DC converter applications up toFigure 1. Typical Application.MINIMUM INPUT VOLTAGEORDER PART NUMBEROutput Power Capability1-418 VDC3 W9 WTOP412GTOP414G24 VDC36 VDC48 VDC60 VDC72 VDC90 VDC12 WTable 1. TOP412/414 Output Power.4 W5 W6 W7 W9 W18 W21 W12 W15 W15 W18 WNotes: 1. Assumes ma FeaturesAuto-restart and cycle by cycle current limiting functionshandle both primary and secondary faultsOn-chip latching thermal shutdown protects the entiresystem against overloadHighly VersatileImplements Buck, Boost, Flyback or Forward topologyEasily interfaces with both opto and primary feedbackSupports continuous or discontinuous mode of operationSpecified for operation down to 16 V DC inputDescription The TOPSwitch family implements, with only three terminals,all functions necessary for a DC to DC, converter: high voltageN-channel power MOSFET with controlled turn-on gate driver,voltage mode PWM controller with integrated 120 kHz oscillator,high voltage start-up bias circuit, bandgap derived reference,bias shunt regulator/error amplifier for loop compensation andfault protection circuitry. Compared to discrete MOSFET andcontroller or self oscillating (RCC) switching converter solutions,a TOPSwitch integrated circuit can reduce total cost, componentcount, size, weight and at the SpecificationSymbolSee Figure 11MinTypMaxUnits