Temperature rising using the LTC3440

Hello,

i am using the LTC3440 to convert the voltage from a LiPo Battery into a stable 3.3V. As you can see in my schematic, i am the following the datasheet. My circuit is drawing 300mA in worst case.

I did some tests with 300mA Load and the outputs is stable on 3.3V. The problem is the temperature on the IC. I am going to measure the temperature but its really hot ( cannot touch it for more than 2-3 seconds).

The inductor is rated for 1.2A max DC current and i am using the max frequency on the converter.

Should i increase the inductors value and decrease the frequency?

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  • Solved.

    Mode/Sync was not the problem. The problem was that Rt resistor on both PCBs was not placed correctly when i first power-up the board in a way that Rt pin was floating.

    When i noticed the solder issue, i soldered the resistor correctly but seems that IC was already damaged.That missing resistor as i spoke with AD support may drive the IC on unexpected mode/function.

    Also i simulated the circuit on LTSpice and when Rt resistor is missing, i can see a currect spike on IC's input 2.7A+.

    Thanks.

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