Features

• 3V to 100V Input Voltage Range
• 2A, 150V Internal DMOS Power Switch
• Low Quiescent Current:
  116μA in Sleep Mode
  390μA 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

Typical Application

Description

The LT®8304/LT8304-1 are monolithic micropower isolated flyback converters. By sampling the isolated output voltage directly from the primary-side flyback waveform, the parts require 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 a small magnetic solution with excellent load regulation. Low ripple Burst Mode operation maintains high efficiency at light load while minimizing the output voltage ripple. A 2A, 150V DMOS power switch is integrated along with all the high voltage circuitry and control logic into a thermally enhanced 8-lead SO package.

The LT8304/LT8304-1 operate from an input voltage range of 3V to 100V and deliver up to 24W of isolated output power. The high level of integration and the use of boundary and low ripple Burst Mode operation result in a simple to use, low component count, and high efficiency application solution for isolated power delivery. The LT8304-1 is specially optimized for high step-up output applications.