• LTC3649 Transient Response Discrepancy

    I notice in real life that the control loop bandwidth appears to be much higher than predicted in the simulation model. The high bandwidth was causing erratic switching behavior at the switch node. Specifically, when operating under load or at higher…

  • LTC3649 Top and bottom switch gate charge

    Hi. To calculate a switching loss for LTC3649 I need to know gate charge of top and bottom power switches, but this information is not provided in datasheet. How should I evaluate switching loss?

  • LTC3649 as lab power supply - circuit


    I would like to build proposed lab power supply based on LTC3649. In the datasheet note, there is simple schematic, where I found a diode:

    Is this diode a zenner one with 40V or just simple rectified diode?

    Diode is connected between Iset and…

  • LTC3649 : rail to rail operation


    I need to charge a 5mF capacitor from an input voltage (28V-56V) to the same output voltage.

    I want to use LTC3649 to precharge this capacitor at a constant current (between 1-- 2 A).

    I think to choose RSET= 1.1M Ohm and Cset = 100nF.

    Is-it possible…

  • LTC3649:INTVCC is not 3.3V,almost equal to input voltage

    INPUT VOLTAGE is 27V,and set output to 21V,the result  turn out to be 26V,INTVCC is 25.6V,is the chip broken?

  • LTC3649 boost capacitor - larger value OK?

    I am designing in LTC3649 for 5-12V input to various (on same board) output voltages: 1.0, 1.8, 3.0, 3.3.

    I do not have any other 100nF capacitors on this board. I am using 2.2uF 25V X5R 0402 capacitor (Murata # GRM155R61E225KE11D) as my all-around general…

  • LTC3649 datasheet circuit fails when powered with load


    Trying to replicate LTC3649 circuit from datasheet p. 20.  When powering it with no load and with no commanded voltage on TRACK pin - crcuit starts ok, but when powering with load (220 ohm res for test) and  commanded 0.75V on TRACK pin - LTC3649 just…

  • LTC3649: part failing when inductive load switched in and out: which pins to check and then protect?

    Dear Power by Linear,

         I've designed the LTC3649 into a medical device whose tip is connected by a cable that could be two meters long (by my estimate - my customer cannot be more exact.) A footswitch enables a relay which connects or disconnects the…

  • LTC3649 current limit - at shor circuit does not work (is that simulation only or real part too?)


    Trying to simulate downloaded LTC3649_DC2112A.asc and it gives strange result:

    Just added current limit resitor 80k to limit current at 1A. At moderate loads (ie 2ohm) it works as expected. But when output is shorted (~0.1ohm)  simulator shows 4A current…

  • LTC3649 how do i control the current overshoot when using current limit featuresame problem with LTM8064

    LTC3649 how do i control the current overshoot when using current limit featuresame problem with LTM8064