Wide VIN Range Flyback Controllers Feature 150°C Maximum Junction Temperature

Mar 31 2009 -MILPITAS, CA
  • Linear Technology Corporation announces the H-Grade version of the LTC3805/-5 current mode programmable frequency flyback controllers. These devices contain all the features necessary to design high efficiency single-ended isolated and non-isolated flyback converters for telecom, datacom, Power-over-Ethernet (PoE), automotive and general housekeeping power supplies. With its ultralow 40µA start-up current, the LTC3805/-5 allows the use of a high-value input resistor and a low-value capacitor for low power dissipation and quick power supply start-up. The LTC3805H-5 differs from the LTC3805H with its lower turn-on voltage of 4.5V instead of 8.4V.


    These parts are ideal for wide input voltage range applications, enabling users to have one power supply for both 48V (36V-75V) and 24V (18V-36V) nominal input systems. The operating frequency is selectable from 70kHz to 700kHz by one external resistor or for noise-sensitive requirements the device can be synchronized to an external clock over the same range. With a standby quiescent current of only 360uA, the LTC3805/-5 is an excellent choice for automotive applications.


    The H-Grade products are tested and guaranteed to a junction temperature of +150°C, compared to the E and I Grade versions, which are specified for +85°C and +125°C maximum operating temperatures, respectively. The LTC3805 H-Grade version is ideal for automotive and industrial applications, which are subjected to high ambient temperatures.


    Both the LTC3805H and LTC3805H-5 are available from stock in the thermally enhanced MSOP-10 package. Pricing starts at $1.76 each for 1,000 piece quantities. For more information, visit www.linear.com.


    Summary of Features: LTC3805H/-5


    • Start up Current of 40µA
    • VIN and VOUT Limited Only by External Components
    • Programmable Turn-On Voltage
    • Adjustable Slope Compensation
    • Programmable Soft-Start
    • Current Mode Control
    • 70kHz to 700kHz Programmable Constant Frequency Operation
    • Synchronizable up to 700kHz
    • Thermally Enhanced MSOP-10 Package

    150°C Operating Temperature Flyback

    LTC3805H-5 PR Image

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