Hello! I want to use the LTC4013 chip to charge the LiTiO battery. I need to charge with a voltage of 2.8 V. I want to charge in 2 stages. First, direct current, and then constant voltage.
As I understand it, I can regulate the maximum charging voltage using pin FB.
I do not understand the values in table 1 (Mode Pin Settings) on page 16. VFLOAT for stage 2 is 2.267. This voltage is too low for my battery.

As I understand it, when this voltage is reached, the charging mode will change from the rated current to a constant voltage, is that so?
Can I change the VFLOATvalue for the modes?

  • 0
    •  Analog Employees 
    on Jun 8, 2020 7:17 PM 7 months ago


    This is no problem with the LTC4013. You want to configure the MODE pins for a 2-stage charge profile.

    The 2.267V figure you see is CV threshold the for FB node itself. So, you use the voltage divider on the FB node to set the CV voltage for your battery.

    Yes, you will start in constant current (CC) mode and when the threshold is reached the charger will transition to constant voltage (CV) mode.

    You can change the CV threshold by changing the FB voltage divider ratio. You might put a resistor in parallel with the bottom FB resistor and switch it in/out using a FET.