A high frequency active voltage doubler in standard CMOS using offset-controlled comparators for inductive power transmission

Hyung Min Lee, Maysam Ghovanloo

Research output: Contribution to journalArticle

35 Citations (Scopus)


In this paper, we present a fully integrated active voltage doubler in CMOS technology using offset-controlled high speed comparators for extending the range of inductive power transmission to implantable microelectronic devices (IMD) and radio-frequency identification (RFID) tags. This active voltage doubler provides considerably higher power conversion efficiency (PCE) and lower dropout voltage compared to its passive counterpart and requires lower input voltage than active rectifiers, leading to reliable and efficient operation with weakly coupled inductive links. The offset-controlled functions in the comparators compensate for turn-on and turn-off delays to not only maximize the forward charging current to the load but also minimize the back current, optimizing PCE in the high frequency (HF) band. We fabricated the active voltage doubler in a 0.5-μrm m 3M2P std. CMOS process, occupying 0.144 mm 2 of chip area. With 1.46 V peak AC input at 13.56 MHz, the active voltage doubler provides 2.4 V DC output across a 1 kΩ load, achieving the highest PCE= 79% ever reported at this frequency. In addition, the built-in start-up circuit ensures a reliable operation at lower voltages.

Original languageEnglish
Article number6220262
Pages (from-to)213-224
Number of pages12
JournalIEEE Transactions on Biomedical Circuits and Systems
Issue number3
Publication statusPublished - 2013 Jan 1
Externally publishedYes



  • Active voltage doubler
  • high speed comparators
  • implantable microelectronic devices
  • inductive power transmission
  • integrated rectifier
  • near field
  • offset control
  • radio-frequency identification (RFID)

ASJC Scopus subject areas

  • Biomedical Engineering
  • Electrical and Electronic Engineering

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