Texas Instruments' TPS54122 combines the efficiency of a step-down switching (DC/DC) converter with a high power-supply rejection (PSR), low-noise, low-dropout regulator (LDO) to provide an ultralow-noise power supply that delivers quiet supply rails to noise-sensitive applications.

With a wide input range of 2.9 V to 5.5 V, the TPS54122 is ideally suited for systems with 5 V power busses, and supports a 3 A continuous output current. The output voltage can be set from 0.8 V to 3.6 V using external resistors. The TPS54122 can be used in a wide range of low-noise applications because the DC/DC converter and LDO are completely configurable. In addition, the TPS54122 includes features such as soft-start, switching frequency synchronization, and a power-good signal. The TPS54122 can also be configured as a dual supply rail device, supplying a total of 3 A.