• Use LT8311 design for 300W in preactive mode.


    I'd like to use LT8311 for 300W power design (VIN=18V~36V), I wonder to know if the LT8311 operating in precative mood continuously, is there any issue or risk will facing?

    Please help to comment or advice, Thanks a lot.

    Have a good day!

  • RE: LT3752 副边续流MOS 尖峰

    LT3752+LT8311, input 200V~500V,output 24V/300W, ratio 5:1, sencondary catch MOS drain Vds has a big spike voltage, RCD snubber can not improve, please advise.

  • LT3753 + LT8311


    We have the reference demo board DC1994A 18-72V to 12V/12A.

    We will modify transformer Np/Ns = 1/3, frequency =250KHz, Duty_max =36.11%, Po=150W

    We looking for the reference design of LT3753 + LT8311 to output 19.5V. Can you provide related schematic…

  • RE: Question about LT3752 & LT8311

    Hi Feiguo,

    Please share the schematic. Can the LT8311 be used in 48V/54V output?



  • LT8311如何设置在轻载强制FCM的问题。

    你好,我用LT3753和LT8311做了一个输入(18V-36V),输出12V的正激电路,我查看芯片资料在初级(SOUT引脚)和次级的(SYNC引脚)加了一个脉冲变压器,芯片(LT8311)会让电路工作在强制FCM模式,但是实际上工作在DCM模式,随着负载增大,才会工作在CCM模式。不知道怎么解决。典型图如下。 改变R22和R29的电阻时,当电阻从小变大,功耗从高变低,驱动从有(有的时候CG会丢失一段波形和FG不是互补的)慢慢变的没有。我查看LT8311的芯片资料(第二十页)上面说有4种模式会LT8311的保护…

  • 您好! 我想使用LT8311设计300W电源并操作在Preactive Mode.


    我想使用LT8311设计于300W电源(VIN=18V~36V), 并想操作在 preactive mode, 请问这样的设计是否适用? 是否有其他的风险? 谢谢!

  • RE: 关于LT3753和LT8311的配合问题

    The front page of the datasheet says:

    "In preactive mode, the output inductor current

    operates in discontinuous conduction mode (DCM) at

    light load. If forced continuous mode (FCM) operation is

    desired at light load, the LT8311 can, alternatively…

  • RE: LT3753+LT8311的配合使用问题。

    The turns ratio (Np:Ns=3.25:4) is not suitable for 9V-36V input range and 12V output. You might use this turns ratio if the minimum input voltage is higher (>16.5V).

    The reference design has a 10uH output inductor. If you want to use a 6.8uH you might…

  • 关于LT3753与LT8311的配合问题

    典型电路按照https://www.analog.com/cn/products/lt8311.html#product-evaluationkit来做的,只不过芯片从LT3752换到了LT3753,匝比为3.25:4(初级:次级),输入18-36V, 输出12V,空载和轻载(0-3A)的时候,测得原边主管的驱动很小比预计的占空比小很多,随着负载加大占空比正常。同时在空载和轻载的时候还测的CG提前关断(相对于互感器T2的输出波形)。空载损耗大块5W接近5W。不知道为啥?

  • RE: LT3752-1 with LT8311: housekeeping flyback not regulating the primary side voltage

    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

    Thank you,