A High 5292-PPI Pixel Circuit for Micro Displays With 10-Bit Gray Levels Realized via the Technique of Analog Sub-Frame Integral
oleh: Shih-Song Cheng, Paul C.-P. Chao
| Format: | Article |
|---|---|
| Diterbitkan: | IEEE 2023-01-01 |
Deskripsi
A pixel circuit driven in small range of data voltage <inline-formula> <tex-math notation="LaTeX">$(V_{data})$ </tex-math></inline-formula> is proposed for high pixel-per-inch (PPI) micro displays, using the new driving technique of analog sub-frame integral (A-SFI) to realize the required current integrals of gray levels. This circuit runs with two analog <inline-formula> <tex-math notation="LaTeX">$V_{data}$ </tex-math></inline-formula>’s configurated by 7-bit digital-to-analog converters (DACs), outputting 10-bit integral currents by receiving a digital voltage of <inline-formula> <tex-math notation="LaTeX">$V_{sel}$ </tex-math></inline-formula> at each sub-frame that is one of eight (3-bit) equally divided from an illuminating period. With the 1-LSB of 5mV assumed, the estimated <inline-formula> <tex-math notation="LaTeX">$V_{data}$ </tex-math></inline-formula> range of 0.64V, which is apparently lower than at least 5V of a conventional circuit made by high voltage FETs (HVFETs), assists the proposed circuit in mainly constructing by the low voltage FETs (LVFETs) that are driven by about 1V; therefore, its pixel layout could be shrank for high PPI. Implementing this circuit in a 1.03-inch, high 5292PPI micro OLED panel made via that 55nm CMOS process for the validations, the simulated results over the displaying range show the <inline-formula> <tex-math notation="LaTeX">${l}$ </tex-math></inline-formula>DNL’s of within +1.15iLSB and −1.01iLSB, the iINL’s of within +1.53iLSB and −1.05iLSB, and the iAD’s of within +1.94% and −1.18%, observed the favorable linearities or deviations to the generated integral currents along 10-bit grayscales. The experimental results show the <inline-formula> <tex-math notation="LaTeX">${l}$ </tex-math></inline-formula>DNL’s of within<inline-formula> <tex-math notation="LaTeX">$3.12{l}$ </tex-math></inline-formula>LSB and <inline-formula> <tex-math notation="LaTeX">$- 1.75{l}$ </tex-math></inline-formula>LSB, and the <inline-formula> <tex-math notation="LaTeX">${l}$ </tex-math></inline-formula>INL’s of within<inline-formula> <tex-math notation="LaTeX">$3.35{l}$ </tex-math></inline-formula>LSB and <inline-formula> <tex-math notation="LaTeX">$- 2.29{l}$ </tex-math></inline-formula>LSB, validated the viability of this technique for high PPI displays.