Embedded fully self-biased switched-capacitor for energy and area-efficient cholesteric LCD drivers

The embedded fully self-biased switched-capacitor (FSBSC) with single-inductor high voltage bipolar-output (SIHBO) converter is proposed to achieve the energy and area-efficient driving scheme for the paper-like cholesteric liquid crystal display (Ch-LCD), which becomes the next generation of electronic readers in the consumer markets. As the compact power management module, SIHBO converter can provide +/-35V bipolar outputs for row driving. Besides, the embedded FSBSC is utilized to generate the different voltage levels for modulating the gray-color in column driving scheme. This combination carries out the effective driving operation for Ch-LCD through the demand of timing control unit. Experimental results show the achievement of +/-35V output voltage in the SIHBO converter and the variety voltage levels generated from FSBSC. The peak efficiency is up to 84% with the silicon area of 6.53 mm².