Abstract

A readout circuit on glass substrate for touch panel application has been designed and fabricated in a 3-$\mu{\hbox{m}}$ low temperature poly-silicon (LTPS) technology. In this work, the switch-capacitor (SC) technique is applied to amplify the small voltage difference from capacitance change due to the touch event on panel. In addition, the corrected double-sampling (CDS) technique is also employed to reduce the offset originated from LTPS process variation. The minimum detectable voltage difference of the proposed circuit is 40 mV. To further identify the different touch area during touch events, a 4-bit analog-to-digital converter is used to converter the output of readout circuit into 4-bit digital codes.

© 2010 IEEE

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2009 (2)

Y.-H. Yu, Y.-J. Lee, Y.-H. Li, C.-H. Kuo, C.-H. Li, Y.-J. Hsieh, C.-T. Liu, Y.-J. Chen, "An LTPS TFT demodulator for RFID tags embeddable on panel displays," IEEE Trans. Microw. Theory Tech. 57, 1356-1361 (2009).

T.-M. Wang, M.-D. Ker, S.-C. Chen, "Design of analog output buffer with level shifting function on glass substrate for panel application," J. Display Technol. 5, 368-375 (2009).

2008 (1)

T.-Y. Lee, C.-C. Chiu, Y.-C. Liu, C.-C. Liu, Y.-C. King, C.-J. Lin, "A new embedded one-time-programmable MNOS memory fully compatible to LTPS fabrication for system-on-panel applications," IEEE Electron Device Lett. 29, 906-908 (2008).

2007 (2)

2006 (1)

IEEE Electron Device Lett. (1)

T.-Y. Lee, C.-C. Chiu, Y.-C. Liu, C.-C. Liu, Y.-C. King, C.-J. Lin, "A new embedded one-time-programmable MNOS memory fully compatible to LTPS fabrication for system-on-panel applications," IEEE Electron Device Lett. 29, 906-908 (2008).

IEEE Trans. Microw. Theory Tech. (1)

Y.-H. Yu, Y.-J. Lee, Y.-H. Li, C.-H. Kuo, C.-H. Li, Y.-J. Hsieh, C.-T. Liu, Y.-J. Chen, "An LTPS TFT demodulator for RFID tags embeddable on panel displays," IEEE Trans. Microw. Theory Tech. 57, 1356-1361 (2009).

J. Display Technol. (4)

Other (11)

K.-H. Lim, H.-W. Kim, J.-S. Kang, Y.-C. Sung, O.-K. Kwon, "A novel 2-stage analog amplifier with self-compensated current loads using low temperature poly-si TFTs for flat panel displays," SID Dig. Tech. (2008) pp. 541-544.

J.-S. Yoon, J.-S. Kang, O.-K. Kwon, "High efficient p-type only cross-coupled DC-DC converter using low temperature poly-si TFTs for mobile display applications," SID Dig. Tech. (2008) pp. 545-548.

H.-J. Chung, Y.-W. Sin, "Low power level shifter for system-on-panel applications," SID Dig. Tech. (2008) pp. 1231-1234.

H. Nakatogawa, T. Tsunashima, Y. Aoki, T. Motai, M. Tada, A. Ishida, H. Nakamura, "3.5 inch VGA TFT LCD with system-on-glass technology for automotive applications," SID Dig. Tech. (2009) pp. 387-390.

Y.-S. Park, D.-Y. Kim, K.-N. Kim, Y. Matsueda, J.-H. Choi, H.-K. Kang, H.-D. Kim, H.-K. Chung, O.-K. Kwon, "An 8 b source driver for 2.0 inch full-color active-matrix OLEDs made with LTPS TFTs," IEEE Int. Solid-State Circuits Conf. Dig. Tech. Papers (2007) pp. 130-132.

J.-E. Pi, C.-S. Pyo, B.-H. Kim, Y.-I. Kim, J.-H. Eom, J.-B. Choi, S.-I. Park, B.-W. Lee, Y.-G. Hwang, C.-W. Kim, "Touch-panel controller implemented with LTPS TFTs," SID Dig. Tech. (2009) pp. 443-446.

Y.-K. Choi, H.-R. Kim, W.-G. Jung, M.-S. Cho, Z.-Y. Wu, H.-S. Kim, Y.-H. Lee, K.-M. Kim, K.-S. Lee, J.-S. Kim, M.-H. Lee, "An integrated LDI with readout function for touch-sensor-embedded display panels," IEEE Int. Solid-State Circuits Conf. Dig. Tech. Papers (2007) pp. 134-135.

S. Takahashi, B.-J. Lee, J.-H. Koh, S. Saito, B.-H. You, N.-D. Kim, S.-S. Kim, "Embedded liquid crystal capacitive touch screen technology for large size LCD applications," SID Dig. Tech. (2009) pp. 563-566.

D. Johns, K. Martin, Analog Integrated Circuit Design (Wiley, 1997).

T. Nakamura, H. Hayashi, M. Yoshida, N. Tada, M. Ishikawa, T. Motai, T. Nishibe, "A touch panel function integrated LCD including LTPS A/D converter," SID Dig. Tech. (2005) pp. 1054-1055.

Mentor Graphics Corp.WarrenNJ“Eldo simulation,” (2007).

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