A current sensing circuit using current-voltage conversion for PMOS-based LDO regulators

In this paper, a standalone output current sensing module for CMOS low dropout linear voltage (LDO) regulator with PMOS as pass device is proposed. The main purpose of current sensing is to create an over-current protection or to limit the output current value in certain applications. Based on I-V conversion in which the supply voltage varies from 2.7 V-4.2 V, the current clamp value varies from 178 mA to 270 mA in the case of 200 mA load limiting. The proposal has been successfully fabricated using a CMOS technology, and verified through the correct operation of a power management prototype chip.