LDO is the output current equal to the input current, and some LDO to set the maximum output current reasons:
1, to prevent the big tube is burned;
2, if so large power consumption above, it will catch fire.
LDO, the low dropout regulator, is a low-voltage differential linear regulator, which is relative to traditional linear regulators. 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.