Study and Design of Low Drop-Out Regulators

The motivation behind the study of low drop-out (LDO) regulators is driven by the increasing demand for higher performance power supply circuits. This paper discusses thoroughly the important issues relevant to the emergence and design of these circuits. An increasing number of low voltage applications require the use of LDOs, i.e., cellular phones, pagers, laptops, etc. Switching regulators, though similar in function, cater to different market demands. The paper further illustrates the design criteria and corresponding analysis relevant to LDOs. This is followed by a discussion on the circuit design considerations under low voltage conditions of the two major components of the regulator in existing process technologies, the pass device and the error amplifier.