An Energy Efficient OLED Lamp Driver for Wearable Light Therapy Device

Abstract

In this study, we propose a power conversion circuit capable of self-compensation for the organic light emitting diode (OLED) based light therapy and optical platform. In order to compensate for degradation caused by a long time operation of the OLED, a constant-current driving of the OLED should be used instead of constant-voltage driving of the OLED. To increase the efficiency of the OLED lamp driver, a single-stage structure which is combined power stage and OLED current driving stage, is suggested. Also, the SenseFET-based current sensor is used for accurate, continuous, and lossless current sensing. This study was conducted based on the TSMC 180-nm BCD process and implemented a high-efficiency OLED driving system with 2V supply voltage, an efficiency of 90.9% at 1MHz.