D03.5 - A 90.9% Peak Efficiency KY Single-Inductor Bipolar-Output Converter with Conductance Modulation Controller for Active-Matrix Organic Light Emitting Diode Power Supply
A single-inductor bipolar-output (SIBO) converter combined with KY boost converter and interleaved switched capacitor (SC) converter with conductance modulation controller is proposed for Active-Matrix Organic Light Emitting Diode (AMOLED) Power Supply. The KY converter demonstrates better efficiency compared to traditional boost converters through charge flow analysis. The SC converter used in this paper effectively addresses the interaction regulation issues present in conventional SIBO converters. By employing an interleaving architecture, the SC converter ensures continuous input current, preventing the positive output voltage from being affected by current fluctuations. To control the SC converter operating in fast switching limit (FSL) mode, conductance modulation is proposed. This approach adjusts the Rds,on value of the power MOSFET to maintain the negative output voltage at the desired level. The chip prototype is implemented in a 180 nm BCD process, The converter achieves a peak efficiency of 90.9%, operating with 1MHz switching frequency.
