Design of LDO Regulator With High Reliability ESD Protection Circuit Using Analog Current Switch Structure for 5-V Applications

The modern electronic device should be able to provide stable voltage and current under a variety of conditions. The LDO regulator used in the electronic device is a system that requires various voltages and load currents. This paper suggests to the LDO regulator with the high reliability ESD protection circuit that achieves low peak voltage through analog switch structure. The proposed LDO regulator has the function of detecting the output voltage fluctuations depending on the load via an analog switch structure and effectively controlling the peak voltage. In addition, as IC is miniaturized and integrated, circuit failures frequently occur in mobile devices using the low voltage due to electrostatic discharge (ESD). The proposed ESD protection circuit is placed on I/O and power lines to prevent the IC circuit from being destroyed from the inevitable ESD phenomenon. Therefore, in this paper, an ESD protection circuit was built into the LDO regulator to verify high reliability from ESD situations. It was verified that the high reliability of the IC can be improved through effective current discharge due to ESD surge. The proposed LDO regulator, implemented in a $0.13\mu \text{m}$ BCD process, achieves an undershoot voltage of 25 mV and an overshoot voltage of 28 mV for a load current of 300 mA.