100V No-Opto Flyback Regulator Delivers Up to 5 Watts in TSOT-23 Package

Sep 15 2016 - MILPITAS, CA
  • Linear Technology Corporation announces the LT8303, a monolithic flyback regulator in a TSOT-23 package that significantly simplifies the design of isolated DC/DC converters. By sampling the isolated output voltage directly from the primary-side flyback waveform, the part requires no opto-isolator, LT1431 or third winding for regulation. The LT8303 operates over a 5.5V to 100V input voltage range, has a 0.45A/150V integrated DMOS power switch and delivers up to 5 watts of output power, making it well suited for a wide range of telecom, datacom, automotive, industrial, medical and military applications.


    The output voltage is set with only one external resistor and the transformer turns ratio. Several off-the-shelf transformers, identified in the data sheet, can be used for numerous applications. The LT8303 operates in boundary mode, which is a variable frequency current mode control switching scheme, typically resulting in ±5% output voltage regulation over the full line, load and temperature range. Boundary mode enables the use of a smaller transformer compared to equivalent continuous conduction mode designs. The high level of integration and the use of low ripple Burst Mode® operation result in a simple to use, low component count and high efficiency application solution for isolated power delivery.

    Additional features include output short-circuit protection, 70µA no load operating quiescent current, internal loop compensation, accurate enable and undervoltage lockout with hysteresis.

    Extended and industrial versions operate over a junction temperature range of –40°C to 125°C. Pricing starts at $3.15 each in 1000-piece quantities. For more information, visit www.linear.com/product/LT8303.

    Summary of Features: LT8303

    • VIN Range from 5.5V to 100V
    • Up to 5W of Output Power
    • On-board 0.45A, 150V Integrated DMOS Power Switch
    • Off-the-Shelf Power Transformers
    • No Opto-Isolator, LT1431 or Third Winding Required for Voltage Feedback
    • 70µA Quiescent Current
    • Boundary Mode Operation
    • VOUT Set with One External Resistor
    • Internal Loop Compensation
    • Accurate Input Enable & Undervoltage Lockout with Hysteresis
    • Small 5-Lead TSOT Package

    Pricing shown is for budgetary use only and may differ due to local duties, taxes, fees and exchange rates.

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