Title :
A Single-Inductor Step-Up DC-DC Switching Converter With Bipolar Outputs for Active Matrix OLED Mobile Display Panels
Author :
Chae, Chang-Seok ; Le, Hanh-Phuc ; Lee, Kwang-Chan ; Cho, Gyu-Ha ; Cho, Gyu-Hyeong
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Korea Adv. Inst. of Sci. & Technol., Daejeon
Abstract :
A single-inductor step-up DC-DC switching converter with bipolar outputs is implemented for active-matrix OLED mobile display panels. The positive output voltage is regulated by a boost operation with a modified comparator control (MCC), and the negative output voltage is regulated by a charge-pump operation with a proportional-integral (PI) control. The proposed adaptive current-sensing technique successfully supports the implementation of the proposed converter topology and enables the converter to work in both discontinuous-conduction mode (DCM) and continuous-conduction mode (CCM). In addition, with the MCC method, the converter can guarantee a positive output voltage that has both a fast transient response of the comparator control and a small output voltage ripple of the PWM control. A 4.1 mm2 converter IC fabricated in a 0.5 mum power BiCMOS process operates at a switching frequency of 1 MHz with a maximum efficiency of 82.3% at an output power of 330 mW.
Keywords :
BiCMOS integrated circuits; DC-DC power convertors; LED displays; PI control; PWM power convertors; comparators (circuits); flat panel displays; mobile handsets; organic light emitting diodes; power integrated circuits; switching convertors; voltage control; IC fabrication; PWM control; active matrix OLED mobile display panels; adaptive current-sensing technique; charge-pump operation; continuous-conduction mode; converter topology; discontinuous-conduction mode; efficiency 82.3 percent; modified comparator control; negative output voltage regulation; positive output voltage regulation; power 330 mW; power BiCMOS process; proportional-integral control; single-inductor step-up DC-DC switching converter; size 0.5 mum; transient response; Active matrix technology; BiCMOS integrated circuits; Charge pumps; Flat panel displays; Matrix converters; Organic light emitting diodes; Pi control; Proportional control; Switching converters; Voltage control; AMOLED; DC-DC converter; bipolar output; body switching; charge pump; comparator control; current sense; single-inductor multiple-output (SIMO);
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.2008.2010986
