• LTC4040 Charging Issue

    Hi All,

    I am using LTC4040 to charge 18650 battery and to generate 5V output. Boost section is fine but charging of battery is not working.

    I have removed NTC and grounded the PIN. And now LED connected to RST and CHRG pin is flickering alternatively…

  • LTC4040 No Charging Battery

    Hello to Everyone,

    i have an issue with LTC4040, no way of let it charge battery (i use a Li-Ion) , i tried every solution/proposal found in this site with people that had the same issue, but nothing worked.

    With the  oscilloscope, the igate of the Mosfet…

  • LTC4040 not charging the battery


    i have looked at the forum and have seen that there are many issues with the battery charging of the ltc4040 ic.

    Unfortunately i am having some issues too and none of the tickets have helped me to resolve my issue. I Have design my PCB by following…

  • LTC4040 backup question

    Dear Sir,

    Our customer have some question when using LTC4040 backup power as below.

    Customer's output had a deep drop(Vsys) when system is change to backup mode(Please see below pic). This drop will cause the output system(watchdog) restart.

  • LTC4040 , removing battery

    Hi all

    I have a small (?) problem
    I want battery cell is completely disconnected when my product is travelling (plane)
    So I first put a bistable relay on pin 23 (BAT) to cell.
    This works perfectly.

    So where is the problem ?

    It's about some shocks.
    In rare…

  • LTC4040


           单板上采用了电池充电芯片LTC4040 ,在单板不用外接电源供电情况下,将电压为3.3V的电池插入电池充电芯片LTC4040 的充电口,也就是SW1 SW2,结果LTC4040就冒烟烧毁,这是什么原因造成的。谢谢!

  • LTC4040 LiFePO4 battery charging profile

    Could you please help provide LTC4040 LiFePO4 battery charging profile. Thank you

  • LTC4040 minimum battery voltage

    Hello - I'd like to use the LTC4040 with a LiFePO4 battery.  At low temperatures (0 C) it has a voltage of 2.5 V even at full charge. The datasheet says that Vbat min is 2.7 V and undervoltage lockout is 2.45 V. 

    1) What is the lowest voltage of Vbat…

  • LTC4040 Use Battery Output Mode

    Dear All:

    The LTC4040 use Li-Battery (4.2V) ,If VSYS is set to 5V output, when Li-Battery (VBAT) is used as the output power source ,VSYS will still keep at 5V or VSYS = VBAT voltage level ,thanks



  • LTC4040


    I have a problem with my LTC4040 schematic. Vsys voltage is 4.8V. Schematic work in buck and boost mode , with / without Vin. The problem is charging. The battery is not possible to charge above 2.8V.  Charging stop when the battery voltage become…