High Voltage, Micropower Isolated Monolithic Flyback Regulator in ThinSOT Simplifies Design

Linear Technology LT8300

Linear Technology Corporation announces the LT8300, a low quiescent current monolithic flyback regulator that significantly simplifies the design of an isolated DC/DC converter. No optocoupler, third winding or signal transformer are required for feedback since the output voltage is sensed from the primary-side flyback signal. The LT8300 operates over a 6V to 100V input voltage range, has a 260mA, 150V power switch and delivers up to 2 watts of output power, ideal for a wide variety of telecom, datacom, automotive, industrial and medical applications.

Linear Technology - LT8300

The LT8300 operates in a boundary mode, a current-mode control switching scheme, resulting in better than ±5% regulation over the full line, load and temperature range. Boundary mode, also known as critical conduction mode (CCM), permits the use of a smaller transformer compared to equivalent continuous conduction mode designs. Low output ripple Burst Mode® operation maintains high efficiency and helps extend battery run times at light load with its low quiescent current. The output voltage is easily set by a single external resistor and the transformer turns ratio. Several transformers identified in the data sheet can be used for numerous applications. Additional features include power, internal soft-start and adjustable undervoltage lockout. The high level of integration results in a simple, low component count, tightly regulated solution ideal for isolated power delivery.

Linear Technology - LT8300
5V Micropower Isolated Flyback Converter

Linear Technology - LT8300
Efficiency vs Load Current

The LT8300 is available in a small 5-lead ThinSOT™ package. Extended and industrial versions operate over a junction temperature range from –40°C to 125°C, and a high temperature automotive grade operates from –40°C to 150°C. Pricing starts at $2.95 each in 1000-piece quantities.

Summary of Features: LT8300

  • VIN Range from 6V to 100V
  • Onboard 260mA, 150V Integrated Power Switch
  • No Optocoupler, Transformer or Third Winding Required for Feedback
  • Low Quiescent Current 330µA when Active
  • Low Component Count
  • Boundary-Mode Operation
  • VOUT Set with A Single External Resistor
  • Off-the-Shelf Transformers
  • Programmable Undervoltage Lockout
  • Internal Soft-Start

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