All-silicon Integrated Photoelectric Microdisplay Driving System

All silicon integrated optoelectronic microdisplay technology has been developing rapidly in recent years.However,in order to make this emerging display technology practical,it is necessary to design a perfect and practical driving circuit corresponding to it.Firstly,the power consumption of the drive system needs to be as low as possible,and the area of the drive system is supposed to be as small as possible so as to meet the requirements of portable and wearable microdisplay.Secondly,a drive system of high precision and high refresh rate is needed so that the output picture could be more vivid and smooth.Based on the standard CMOS technology,an 8×8 all-silicon integrated photoelectric microdisplay drive system is proposed.The main work is as follows:(1)The addressing circuit of silicon based microdisplay is designed.The addressing circuit is usually divided into column part and row part.The column circuit consists of shift register and data latch.Display data is sorted,stored in a column circuit,converted by DAC and transferred to a pixel matrix.The row circuit mainly provides signal control line scan mode.Since D flip-flop is the basic element of the addressing circuit,considering the current leakage of the transistor of dynamic D flip-flop in the subthreshold region,static logic D flip-flop is selected as the basic element of the addressing circuit.Simulation results based on 8×8 module show that the addressing circuit works normally.(2)Based on the standard 0.18?m CMOS process,a 12-bit Digital to Analog Converter(DAC)is designed for low-power applications.In the design,based on the compromise of area,power consumption and speed,the DAC adopts the hybrid structure of current rudder and R-2R trapezoidal resistor.Through MATLAB modeling,the piecewise structure of(3+5+4)is adopted,which has a smaller chip area compared with the traditional piecewise current-steering DAC structure.The highest three bits and the middle five bits select the temperature decoding current rudder structure,and the lowest four bits select the R-2R trapezoidal resistance structure.The simulation results show that under 1.8V power supply voltage,the output voltage swing is 1V,the differential nonlinear DNL=0.5LSB,and the integral nonlinear INL=0.6LSB.The average power consumption is 6.012 m W and the establishment time is 19 ns.At the TT process corner,the sampling clock is 300 MHz.When the input sinusoidal signal frequency is 12.89 MHz,SFDR and ENOB are 79.57 d B and 11.88 bit respectively.When the input sinusoidal signal frequency is 148.83 MHz,SFDR and ENOB are 72.56 d B and 11.46 bit respectively.(3)Because the display brightness of microdisplay is proportional to the driving current density,the current driving scheme is selected in this thesis.At the same time,the factors such as driver transistor type,parasitic capacitance,switch feed-through and clock feed-through were considered to optimize the pixel circuit,and multiple CMOS transfer gate switches and Cascode current mirror structure are determined to design the current compensation pixel circuit.The simulation results show that the error of the pixel circuit is within 1%.Finally,the maximum power consumption of the all silicon integrated photoelectric microdisplay driving system with a scale of 8 × 8 is 349.63 m W.