
Linear Technology
DESCRIPTION
The LT®8302 is a monolithic micropower isolated flyback converter. By sampling the isolated output voltage directly from the primary-side flyback waveform, the part requires no third winding or opto-isolator for regulation. The output voltage is programmed with two external resistors and a third optional temperature compensation resistor. Boundary mode operation provides asmall magnetic solution with excellent load regulation. Low ripple Burst Mode operation maintains high efficiency at light load while minimizing the output voltage ripple. A 3.6A, 65V DMOS power switch is integrated along with all the high voltage circuitry and control logic into a thermally enhanced 8-lead SO package.
FEATUREs
■ 2.8V to 42V Input Voltage Range
■ 3.6A, 65V Internal DMOS Power Switch
■ Low Quiescent Current:
106µA in Sleep Mode
380µA in Active Mode
■ Quasi-Resonant Boundary Mode Operation at Heavy Load
■ Low Ripple Burst Mode® Operation at Light Load
■ Minimum Load < 0.5% (Typ) of Full Output
■ No Transformer Third Winding or Opto-Isolator
Required for Output Voltage Regulation
■ Accurate EN/UVLO Threshold and Hysteresis
■ Internal Compensation and Soft-Start
■ Temperature Compensation for Output Diode
■ Output Short-Circuit Protection
■ Thermally Enhanced 8-Lead SO Package
APPLICATIONS
■ Isolated Automotive, Industrial, Medical Power Supplies
■ Isolated Auxiliary/Housekeeping Power Supplies