Low Dropout (LDO) Linear Voltage Regulators, 400mA, ON Semiconductor This remarkable ON Semiconductor linear voltage regulator comes under the LDO (Low dropout) family. These products are monolithic integrated circuits designed as fixed-voltage regulators for a wide range of applications including local, on-card regulation. LDO voltage regulators may offer fast transient response, wide input voltage range, low quiescent current and low noise with high PSRR.