Black Box Small-Signal Model of PMOS LDO Voltage Regulator

caroline11

Abstract—This paper presents a black box small-signal modeling of a low-dropout (LDO) voltage regulator. The small-signal model is derived for each part of the system around an operating point. Then, the closed-loop transfer-functions are obtained to build a five port network model of the LDO. The analytical solution is validated by simulation comparison with transistorlevel implementation of a PMOS LDO in a 90nm CMOS process from STMicroelectronics. Due to the hand calculation difficulty, we proposed an automated extraction flow based on the QZ algorithm. The flow is verified with the model extraction of a complex PMOS LDO, designed in a 55nm STMicroelectronics CMOS process.