All-digital single-inductor multiple-output DC-DC converter with over 65.3% efficiency in 1 uW to 50 mW load range and 86.3% peak efficiency

This paper presents a wide load range all-digital single-inductor multiple-output (SIMO) DC-DC buck converter. Since sensor nodes for the Internet of Things (IoT) operate mostly in a standby mode and occasionally in an active mode, a SIMO DC-DC converter supporting a wide load range with practical conversion efficiency is required. In order to achieve practical efficiency in a wide load range, three new techniques of a maximum-on-time control, a channel-consolidated-multiple-switching and a logic-gate-based zero-current-detection circuit are proposed. The proposed SIMO DC-DC converter achieves 86.3% peak efficiency and the wide load range from 1 uW to 50 mW with over 65.3% efficiency. This is the first SIMO DC-DC converter with over 60% efficiency in such a wide load range.