Design and implementation of capacitive sensor readout circuit on glass substrate for touch panel applications

Fabrication, nanoindentation characteristics, and optical spectroscopy of patterned ITO for multi-touch panel are investigated. The fabrications were carried out in two parts. The first part fabricates the high/low impedances of ITO patterns on silicon wafer, and the second part sputters the ITO patterns on PET film using MEMS fabrication. The array strips of ITOs on the PET film are defined as contact areas and row electrodes of scanning lines. The ITO patterns on the glass substrate include the contact areas, the narrow wires for high impedance, and the column electrodes of scanning lines for low impedance. The nanoindentation characteristics of load-unload regions generated elastic energy dissipation, which is attributed to higher elastic response, frictional energy, stiffness, and compressive plastic deformation. The maximum transmittance is 74.2% at the wavelength of about 692 nm due to a thicker ITO and Al films.

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Design and implementation of a submerged capacitive sensor in PID controller to regulate the concentration of non-denatured ethyl alcohol

2015 International Seminar on Intelligent Technology and Its Applications (ISITIA) ◽

10.1109/isitia.2015.7219951 ◽

2015 ◽

Cited By ~ 6

Author(s):

Muhammad Rivai ◽

Masaji Suwito ◽

Peter Chondro ◽

Shanq-Jang Ruan

Keyword(s):

Ethyl Alcohol ◽

Pid Controller ◽

Capacitive Sensor ◽

Design And Implementation

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Wide Input Range Supply Voltage Tolerant Capacitive Sensor Readout Using On-Chip Solar Cell

Journal of Circuits System and Computers ◽

10.1142/s0218126616400065 ◽

2015 ◽

Vol 25 (01) ◽

pp. 1640006

Author(s):

Suyan Fan ◽

Man-Kay Law ◽

Mingzhong Li ◽

Zhiyuan Chen ◽

Chio-In Ieong ◽

...

Keyword(s):

Solar Cell ◽

Power Consumption ◽

Supply Voltage ◽

Capacitive Sensor ◽

Cmos Process ◽

Readout Circuit ◽

Worst Case ◽

Average Power Consumption ◽

Input Range ◽

On Chip

In this paper, a wide input range supply voltage tolerant capacitive sensor readout circuit using on-chip solar cell is presented. Based on capacitance controlled oscillators (CCOs) for ultra-low voltage/power consumption, the sensor readout circuit is directly powered by the on-chip solar cell to improve the overall system energy efficiency. An extended sensing range with high sensing accuracy is achieved using a two-step successive approximation register (SAR) and delta-sigma ([Formula: see text]) analog-to-digital (A/D) conversion (ADC) scheme. Digital controls are generated on-chip using a customized sub-threshold digital standard cell library. Systematic error analysis and optimization including the finite switch on-resistance, buffer input-dependent delay, and SAR quantization nonlinearity are also outlined. High power supply rejection ratio (PSRR) is ensured by using a pseudo-differential topology with ratiometric readout. The complete sensing system is implemented using a standard 0.18[Formula: see text][Formula: see text]m complementary metal-oxide-semiconductor (CMOS) process. Simulation results show that the readout circuit achieves a wide input range from 1.5[Formula: see text]pF to 6.5[Formula: see text]pF with a worst case PSRR of 0.5% from 0.3[Formula: see text]V to 0.42[Formula: see text]V (0.67% from 0.3[Formula: see text]V to 0.6[Formula: see text]V). With a 3.5[Formula: see text]pF input capacitance and a 0.3[Formula: see text]V supply, the [Formula: see text] stage achieves a resolution of 7.1-bit (corresponding to a capacitance of 2.2[Formula: see text]fF/LSB) with a conversion frequency of 371[Formula: see text]Hz. With an average power consumption of 40[Formula: see text]nW and a sampling frequency of 47.5[Formula: see text]kHz, a figure-of-merit (FoM) of 0.78[Formula: see text]pJ/conv-step is achieved.

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Design and Implement the Readout Circuit of an In-Cell High-Resolution Capacitive Touch Panel

ASME 2017 Conference on Information Storage and Processing Systems ◽

10.1115/isps2017-5436 ◽

2017 ◽

Author(s):

Tsung-Yen Ku ◽

Paul C.-P. Chao ◽

Chin-Hai Huang ◽

En-Chih Liu ◽

Ming-Hua Yeh ◽

...

Keyword(s):

High Resolution ◽

Cell Structure ◽

Thin Film Transistor ◽

Frame Rate ◽

Readout Circuit ◽

Charge Amplifier ◽

Touch Panel ◽

Capacitance Method ◽

Capacitor Charge ◽

Charge Change

This paper proposes a high resolution capacitive touch panel readout circuit to sense the Variation by self-capacitance method. This AM display of in-cell structure includes an active architecture for improved resolution, that controlling the TFT (Thin-film transistor) to make the accuracy better. In addition, the panel has 60 sensing point per 0.88 inches and the proposed readout circuit used switched capacitor charge amplifier (SCCA) to sensing the charge change and enhances the SNR (Signal-to-noise) by eliminating the baseline. The experimental results show that the proposed readout circuit SNR achieves 38dB and the frame rate is 200Hz.

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