P‐58: Efficiency Enhancement by Non‐Overlapping Time Design and Adaptive Ratio Control for Charge Pump of Display Drivers

Abstract

In this paper, a high-efficiency solution to multi-phase charge pump with full-coverage integer voltage conversion ratios (VCRs) ranges from 1 to 2 n is proposed. To improve the systematic efficiency of multi-phase charge pump, the critical aspect of nonoverlapping (NON) time is designed. To precisely set the NON time of multi-phase clock signals, counter-based solution is proposed. The solution makes NON time to be evenly inserted into every clock phase and achieves equal charging period. In addition, an efficiency enhancement scheme is used by turning off some unnecessary converter stages to improve the efficiency at some particular VCRs. Based on 0.25process, this proposed control strategy is conducted in a multi-phase power converter. And its peak efficiency and current drivability can reach 96% and 6 mA, respectively. Author KeywordsMulti-phase charge pump; counter-based; efficiency enhancement; current drivability; display driver.

P‐33: A High Current‐Drive, Step‐Up Capacitive Power Converter for Display Driver

“…The frequency is set to 100 kHz and more detailed parameters of the implemented circuit is shown in Table 2. The circuit performances of the proposed switch-reduction charge pump topology and the previous structure [9] are shown and compared in Fig. 7.…”