A 0.15 v input energy harvesting charge pump with dynamic body biasing and adaptive dead-time for efficiency improvement

Jungmoon Kim, Philip K T Mok, Chulwoo Kim

Research output: Contribution to journalArticle

62 Citations (Scopus)


A charge pump using 0.13-μm CMOS process for low-voltage energy harvesting is presented. A low-power adaptive dead-time (AD) circuit is used which automatically optimizes the dead-time according to the input voltage. A negative charge pump is also utilized for high efficiency at low input voltages VIN. The AD circuit improves efficiency by 17% at VIN of 0.2 V compared to the fixed dead time circuit as well as enables the charge pump to work at VIN down to 0.15 V. Dynamic body bias (DBB) and switch-conductance enhancement techniques are applied to a unit stage of the three-stage charge pump. The reverse current flowing through the cross-coupled NMOS switches is prevented and the current transfer is also maximized. Together with the AD circuit and the DBB technique, the maximum output current was improved by 240% as compared to the conventional charge pump design using only the forward body bias.

Original languageEnglish
Article number6998083
Pages (from-to)414-425
Number of pages12
JournalIEEE Journal of Solid-State Circuits
Issue number2
Publication statusPublished - 2015 Feb 1



  • Body biasing
  • boost converter
  • charge pump
  • conversion efficiency
  • dc-dc converter
  • dead-time
  • energy harvesting
  • low voltage
  • threshold voltage
  • variation

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

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