A Design of a Power-Up Circuit for Energy Harvesting Applications

This paper presents a power-up circuit design for energy harvesting applications. The two main blocks of the power-up circuit are bandgap reference (BGR) and a low dropout voltage regulator (LDO). A soft-start circuit is added to the bandgap reference circuit to stabilize the output voltage of BGR and LDO. To protect the circuit from noise and fluctuation, the BGR employs a current-mode regulator. The BGR generates a fixed output voltage of 1.2 V. The input voltage of the power-up circuit is 4.2 V and the output voltage is 3.3 V with a load current is 40 mA. The Power Supply rejection ratio achieved by the circuit is -59.9 dB and -50.5 dB for BGR and LDO, respectively. The line regulation and load regulation of the proposed LDO are 3.04 mV/V and 6.8 mV/mA, respectively. The proposed power-up circuit is implemented in 130 nm Bipolar-CMOS-DMOS (BCD) technology with an active area of 576 mu m x 432 mu m. The functionalities and performance of the LDO are verified in Cadence Virtuoso.