• 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 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…

  • RE: LTC3805-5 multiple output by flyback

    Hi T-yoshi,

    More output windings can be added to the transformer to get other output voltages. However, only the main output with feedback loop would be fully regulated. The other outputs may have 10%-15% regulation.

    I can see some dual output examples…

  • 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 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…

  • 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 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…

  • 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…

  • 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
  • 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。