UC3901DWTR ,Isolated Feedback GeneratorFEATURES DESCRIPTION• An Amplitude-Modulation System for The UC1901 family is designed to solve man ..
UC3901J , Isolated Feedback Generator
UC3901J , Isolated Feedback Generator
UC3901N ,Isolated Feedback GeneratorMAXIMUM RATINGS (Note 1)Input Supply Voltage, VIN . . . . . . . . . . . . . . . . . . . . . . . . . ..
UC3901N ,Isolated Feedback GeneratorUC1901UC2901UC3901Isolated Feedback Generator
UC3901Q ,Isolated Feedback GeneratorUC1901UC2901UC3901Isolated Feedback Generator
UN9210 ,Silicon NPN epitaxial planer transistorTransistors with built-in ResistorUN9211/9212/9213/9214/9215/9216/9217/9218/9219/9210/921D/921E/921 ..
UN9210J ,Composite DeviceAbsolute Maximum Ratings T = 25°CaParameter Symbol Rating UnitCollector to base voltage V 50 VCBOC ..
UN9211 ,Silicon NPN epitaxial planer transistorFeaturesn1l Costs can be reduced through downsizing of the equipment and– –reduction of the number ..
UN9211J ,Composite DeviceAbsolute Maximum Ratings T = 25°CaParameter Symbol Rating UnitCollector to base voltage V 50 VCBOC ..
UN9212 ,Silicon NPN epitaxial planer transistorFeaturesn1l Costs can be reduced through downsizing of the equipment and– –reduction of the number ..
UN9212J ,Composite DeviceFeatures• Costs can be reduced through downsizing of the equipment and12reduction of the number of ..
UC3901DWTR
Isolated Feedback Generator
UC1901
UC2901
UC3901Isolated Feedback Generator
FEATURES An Amplitude-Modulation System for
Transformer Coupling an Isolated
Feedback Error Signal Low-Cost Alternative to Optical
Couplers Internal 1% Reference and Error
Amplifier Internal Carrier Oscillator Usable to
5MHz Modulator Synchronizable to an
External Clock Loop Status Monitor
DESCRIPTIONThe UC1901 familyis designedto solve manyof the problems associ-
ated with closinga feedback control loop acrossa voltage isolation
boundary. Asa stable and reliable alternativetoan optical coupler, these
devices featurean amplitude modulation system which allowsa loop er-
ror signal to be coupled with a small RF transformer or capacitor.
The programmable, high-frequency oscillator within the UC1901 series
permits the useof smaller, less expensive transformers which can readily builtto meet the isolation requirementsof today's line-operated power
systems. As an alternativeto RF operation, the external clock inputto
these devices allows synchronizationtoa system clockorto the switch-
ing frequency of a SMPS. additional featureisa status monitoring circuit which providesan active-
low output when the sensed error voltageis within ±10%of the reference.
The DRIVERA output, DRIVERB output, and STATUS output are disabled
until the input supply has reacheda sufficient levelto allow proper operation the device.
Since these devices can alsobe usedasa DC driver for optical couplers,
the benefitsof 4.5to 40V supply operation,a 1% accurate reference, anda
high gain general purpose amplifier offer advantages even though an AC
system may notbe desired.
UC1901 SIMPLIFIED SCHEMATICNovember S
