LDO is a linear voltage regulator. Linear regulators use transistors or FETs operating in their linear region to subtract the excess voltage from the input voltage to produce a regulated output voltage. In popular terms, it is a power management IC, usually used for 12V to 5V,3.3V,1.8V, we do LCD board cards, which use a lot, we use Shanghai Bailiwei LDO and DC-DC. Good quality, and other manufacturers such as micro.