• Compensation loop of LTC3805 Flyback


    I'm designing 3-output flyback power supply using LTC3805-5 using Type-2 compensation network.

    Is there any application note that talks in detail about compensation loops of LTC3805 controller? I'm simply amazed to find so little information…

  • LTC3805-5 seems working incorrectly

    Hello, I am going to use LTC3805-5 as the controlling circuit of a flyback converter.

    Firstly, I built a small circuit to get some knowledge of the chip. The schematic is shown below:

    The components in the shadow are not installed on the pcb. It is…

  • LTC3805 issue in boost configuration

    Hello everybody,

    I'm working on a boost converter, used to boost a 400V input voltage up to 550V.

    The circuit is build around the LTC3805 but I figure out mainly a startup problem: after the controller issues 4-5 pulses, it stop to work. After some…

  • LTC3805-5 min duty cycle question


    I'm building a flyback using LTC3805-5 and my input voltage conditions are 30V - 300V and have 3 outputs 18, 12 and 5.5V. The total load on my power supply is about 16W.

    I wanted to know the what would be the implications of having a duty cycle…

  • LTC3805-5 Minimum Startup Voltage (Vcc)

    I am  unable to get the LTC3805 to start at any voltage less that 8.6V.  I've played with a number of variation of the downloadable demo circuit on the tools and simulations page at https://www.analog.com/en/products/ltc3805.html#product-tools, and…

  • LTC3805-5 multiple output by flyback

    Hi team,

    I am considering 3 or 4 outputs by flyback method.

    Is there a circuit diagram or evaluation board that can be used as a reference?

    I would like to compare what kind of circuit it will be.

    Best regards,


  • LTC3805 Ith Pin Clamp Voltage and current

    Hi All,

    I'm using the LTC3805 flyback in a configuration with feedback through an opto similar to the "typical application" on page 17 of the datasheet:

    However, I run the system at very light loads sometimes and I am wondering what the…

  • Why LTC3805-5 restarts again and again?

    I have the following circuit.

    The components with cross over them are not installed on the board.

    I have made two boards and made a few measurement of the boards separately. Here is the result.

    board #1 board #2
  • How to use the sync pin of the LTC3805

    Hello People,

    I'm using a LTC3805 in a sepic design and I have some questions regarding the sync input.

    I have a Vin of 19V to 24V, Vout of 20V and -20V at Iout(max) of 260mA and -200mA. I use two coupled inductors of 330uH and the sense resistor…

  • LTC3805-5通电后没有反应


    我在使用LTC3805-5设计flyback converter时,发现通电后LTC3805-5的GATE引脚没有输出驱动信号。VCC和RUN上有电压,都是5V;FS引脚上没有看到任何波形。