The TPS720xx family of dual rail, low-dropout linear regulators (LDOs) offers outstanding ac performance (PSRR, load and line transient response), while consuming a very low quiescent current of 38µA.The VBIAS rail that powers the control circuit of the LDO draws very low current (on the order of the quiescent current of the LDO) and can be connected to any power supply that is equal to or greater than 1.4V above the output voltage. The main power path is through VIN, which can be a lower voltage than VBIAS; it can be as low as VOUT + VDO, increasing the efficiency of the solution in many power-sensitive applications. For example, VIN can be an output of a high-efficiency, dc-dc step-down regulator.The TPS720xx supports a novel feature in which the output of the LDO regulates under light loads when the IN pin is left floating.