P-54: A Single-Inductor Bipolar-Output Converter with Power Conservation Mechanism (PCM) for Driving Cholesteric LCD

Cholesteric liquid-crystal display (Ch-LCD) has the bi-stable characteristic to achieve the energy-saving for the green technology. Backlight is even unnecessary in the Ch-LCD system. The single-inductor bipolar-output (SIBO) converter is one of best candidate to supply the power management function for the Ch-LCD with dual positive and negative output voltages by using a single inductor for a compact solution. The energy control methodology with the current-mode control and the power conservation mechanism (PCM) can strengthen the voltage quality to get high display quality. The test chip fabricated by 0.25 μm CMOS technology demonstrates the non-noticeable cross-regulation at dual outputs with 90 % peak power conversion efficiency.