Title :
Charge pump circuit for depletion-mode oxide TFTs
Author :
Oh, M.W. ; Leem, H.G. ; Yoon, Sung Min ; Byun, C.W. ; Park, Sang Hee Ko ; Oh, Hwa Sub ; Park, Kyu Chang
Author_Institution :
Dept. of Electron. Eng., Konkuk Univ., Seoul, South Korea
Abstract :
A charge pump circuit suitable for depletion-mode oxide thin-film transistors (TFTs) is presented. In this circuit, negative gate-to-source bias is applied to turn off the n-type oxide TFTs because they have negative threshold voltages (VT). For this operation, two different supply voltages are used, i.e. VDD and VDD/2. Spice simulation shows that the power efficiency is about 70% in generating VDD × 2 output voltage with 50 μA load current. The output voltages of the fabricated circuits are comparable to those of the simulation results.
Keywords :
SPICE; charge pump circuits; thin film transistors; Spice simulation; charge pump circuit; depletion-mode oxide TFT; depletion-mode oxide thin-film transistors; n-type oxide TFT; negative gate-to-source bias; power efficiency;
Journal_Title :
Electronics Letters
DOI :
10.1049/el.2011.0022
