A new analog buffer using P-type poly-Si TFTs for active matrix displays

• Published in: IEEE electron device letters Vol. 27; no. 1; pp. 40 - 42
• Main Authors: JUNG, Sang-Hoon, NAM, Woo-Jin, LEE, Jae-Hoon, HAN, Min-Koo
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.01.2006; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Active matrix displays; Active matrix liquid crystal displays; Active matrix organic light emitting diodes; Analog buffer; Applied sciences; boot-strapping; Buffer storage; Buffers; Capacitors; Circuits; Design. Technologies. Operation analysis. Testing; Display; driving circuit; Electric potential; Electronics; Exact sciences and technology; Integrated circuits; Offsets; Operational amplifiers; Optoelectronic devices; PMOS; poly-Si thin-film transistor (TFT); Semiconductor devices; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Stores; Subthreshold current; Thin film transistors; Threshold voltage; Timing; Transistors; Voltage; Voltage threshold; PMOS; Polycrystal; PMOS technology; LED displays; Output circuit; Driver; Matrix display; Offset voltage; boot-strapping; poly-Si thin-film transistor (TFT); Active matrix; p type semiconductor; Output voltage; Analog buffer; Integrated circuit; Organic light emitting diodes; Optoelectronic device; Liquid crystal displays; Thin film transistor; Flat panel displays; Separator circuit; Capacitor; driving circuit
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2005.859949

A new simple analog buffer employing p-type low-temperature poly-Si thin-film transistors (TFTs) are proposed and fabricated for the integrated data driving circuits of AMLCD and AMOLED. The new analog buffer does not use any capacitors to store the threshold voltage of a poly-Si TFT, so that it could reduce the output offset by the subthreshold current of poly-Si TFT. The simulation and experimental result exhibit that the buffer output successfully charges the buffer load (/spl sim/20 pF) to the input value quickly by the boot-strapping. The measured output offset voltages are less than /spl plusmn/70 mV when the input varies from 1 to 10 V.