100V Synchronous Forward Controller Regulates Output Voltage without an Opto-Coupler

Aug 20 2014 - MILPITAS, CA
  • Linear Technology Corporation announces the LT8310, a primary-side synchronous forward controller. The LT8310 operates over an input voltage range of 6V to 100V, is targeted for power levels up to 200W and provides a drive signal for secondary-side synchronous rectification to improve efficiency.

    Output voltage regulation of ±8% can be attained without the use of an opto-coupler. When an opto-coupler is used, ±1.5% regulation can be realized. A programmable volt-second clamp provides a safeguard for transformer reset that prevents saturation and protects the MOSFET. This function optimizes the transformer and MOSFET, reducing solution size.

    The LT8310 computes the duty cycle required to create a constant VOUT in open loop applications, thereby simplifying the design. In closed loop applications, the LT8310 limits maximum VOUT if the opto-coupler path breaks open.

    Additional features include programmable overcurrent protection, adjustable input undervoltage, overvoltage lockout and built-in thermal shutdown. The LT8310 has a programmable 100kHz to 500kHz operating switching frequency and can be synchronized to an external clock, enabling the use of a wide range of output inductor values and transformer sizes.

    The LT8310 is available in a TSSOP-20 package with several pins removed for high voltage spacing. The LT8310 E- and I-grade versions operate from a –40°C to 125°C junction temperature. The LT8310 H grade is guaranteed to operate from a –40°C to 150°C operating junction temperature. The LT8310 MP grade is guaranteed to operate from –55°C to 150°C operating junction temperature. The 1,000-piece price starts at $2.99 each. For more information, visit www.linear.com/product/LT8310.

    Summary of Features: LT8310

    • Wide VIN Range: 6V to 100V
    • Programmable Volt-Second Clamp
    • No Opto-Coupler Required
    • High Efficiency Synchronous Rectification
    • Short-Circuit Protection
    • Selectable Fixed Operating Frequency from 100kHz to 500kHz
    • Synchronizable to External Clock
    • Programmable OVLO & UVLO with Hysteresis
    • Extended & Industrial Grades: –40°C to 125°C Operating Junction Temp
    • Automotive Temp Grade: –40°C to 150°C Operating Junction Temp
    • Military Temp Grade: –55°C to 150°C Operating Junction Temp

    Active Clamp Synchronous Forward Controller


    The USA list pricing shown is for budgetary use only. International prices may differ due to local duties, taxes, fees and exchange rates.

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