A Fibonacci-Like Charge Pump and its Current Drive Capacity Enhancement for Display Driver Ics by Dedong Ding
In this work, a mixed-Fibonacci charge pump scheme with gate drive enhancement is proposed to provide as high as 30 V output voltage for display driver integrated circuits (ICs). By generating a high supply voltage (<6.6 V) with a first voltage doubler charge pump, the subsequent Fibonacci charge pump engages more middle-voltage (MV) power transistors and more MV control signals. This improves the current drive capacity by approximately 50%-120%, and the power efficiency is optimized by approximately 10%. Alternatively, it saves about 50% of chip size compared with the traditional scheme. Based on a 0.11 μm 1.5 V/6 V/32 V process, the design is fabricated and the performance improvement is validated. The novel one can achieve a peak current drive capacity of 1.74 mA and its peak power efficiency is 74%
A Novel Pixel Circuit Providing Expanded Input Voltage Range for OLEDoS Microdisplays by Binjie liu
A novel pixel circuit providing expanded data voltage range is proposed for high resolution and high image quality organic light-emitting diode-on-silicon (OLEDoS) microdisplay applications. The proposed pixel circuit adopts a structure of four series connected NMOSFETs (4-SCN) to expand the input data voltage range, within which the circuit operates in the subthreshold region. In addition, the pixel circuit has improved image quality by introducing a compensation scheme. The proposed circuit is verified by the simulation based on a 0.18 μm BCDlite Isolation process. The proposed circuit can be integrated into a unit sub-pixel area of 2.9 × 8.7 μm2. The simulation results show that the input data voltage range of the proposed pixel circuit is 6.26 times wider than that of the traditional 2T1C pixel circuit, which is 4.42V. And the emission current deviation ranges from -4.7% to +4.2% under the threshold voltage variation of ±5 mV, which is 31.01% for a traditional 2T1C pixel circuit.