LDO is the low dropout regulator, meaning the low voltage difference linear regulator, which is relative to the traditional linear regulator. Traditional linear regulators, such as the 78xx series of chips, require the input voltage to be more than 2v to 3V higher than the output voltage, otherwise it will not work properly. However, in some cases, such conditions are obviously too harsh, such as 5v to 3.3v, and the pressure difference between the input and output is only 1.7v, which is obviously not satisfied. For this situation, there is the LDO class power conversion chip.