Fractional Order Low-Dropout Voltage Regulator

The Internet of Things offers tremendous potential to increasingly harness wireless and portable systems in everyday life. Low-dropout (LDO) linear regulators are essential components in numerous wireless and portable electronic devices and their performance in systems can be very important, given the need to power such devices particularly in scenarios with limited energy available. In this paper, the basic low-dropout regulator utilizing fractional order capacitors is investigated. A fractional order model is presented for the voltage regulator, and the corresponding transfer function is derived. From the transfer function, it is shown that the system stability performance depends upon the fractional order, offering increased flexibility in the design process, compared to the integer-order LDO regulator. Furthermore using fractional order components offers increased degrees of freedom in shaping the transfer function, beyond that of traditional pole and zero placement in integer order systems. Analytical findings are explored and validated via numerical simulations. This work provides valuable insights into the design space for using fractional order circuits to meet targeted LDO regulator system performance.