Replace 3.3v ldo with a switching regulator

[usedhondacivic]

The LDO chip (MIC5504-3.3YM5) is attached to the output of the charging IC (BQ24072RGT). This output
works well when fed from nominal battery voltages, eg 3.3 to 4.2 volts, where it will sink up to 0.5 W.

During the nominal charging cycle when the battery voltage exceeds 3.1V but is less than 4.0V, the charging IC will enter "constant current fast charge" mode. In this mode, the voltage increase as needed to create the correct charging current. Because of the dynamic power path feature of the charger, this voltage also appears at the chargers output.

I've recorded this voltage going up to 6.5V, which is >= the 5.5v limit for the LDO. This will cause it to heat up rapidly and eventually burn out.