A Near-Threshold Voltage Startup Monolithic Boost Converter with Adaptive Sleeping Time Control

Abstract

A novel near-threshold voltage startup monolithic boost converter is presented in this paper using an adaptive sleeping time control (ASTC) scheme for low-power applications. The proposed ASTC scheme can promote the power efficiency of the current-mode boost converter under light load by automatically adjusting the sleep time of the converter, and the converter's quiescent current drops down to 4[Formula: see text][Formula: see text]A during the sleeping period. In addition, a new soft-start method is introduced to make the boost converter start up with a near-threshold input voltage. The proposed boost converter was fabricated in a standard 0.18[Formula: see text][Formula: see text]m CMOS process and occupies a small chip area of 0.50[Formula: see text][Formula: see text][Formula: see text]mm. Experimental results show that the boost converter achieves the minimum 0.5-V startup voltage when the output voltage is set to 1.8[Formula: see text]V. After startup, the input voltage range can be expanded from 0.3[Formula: see text]V to 1.5[Formula: see text]V with a switching frequency of 1[Formula: see text]MHz. In addition, a peak efficiency of 94% and a minimum efficiency of 81% are measured at the 1.5-V input voltage as the load current ranges from 0.1[Formula: see text]mA to 100[Formula: see text]mA.