Browsing by Author "Wang, Tzu-Ming"

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2xVDD-tolerant crystal oscillator circuit realized with 1xVDD CMOS devices without gate-oxide reliability issue
(2008)
Ker, Ming-Dou
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Wang, Tzu-Ming
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Liao, Hung-Tai
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電機學院
;
College of Electrical and Computer Engineering
A new 2xVDD-tolerant crystal oscillator circuit realized with 1xVDD CMOS devices without suffering gate-oxide reliability issue is proposed, which is one of the key mixed-voltage I/O cells in a cell library. The proposed circuit is realized with only thin gate-oxide devices with floating n-well technique. The proposed 2xVDD-tolerant crystal oscillator circuit has been designed and verified in a 90-mn 1-V CMOS process to serve 1/2-V mixed-voltage interface applications.
A new architecture for charge pump circuit without suffering gate-oxide reliability in low-voltage CMOS processes
(2007)
Wang, Tzu-Ming
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Shen, Wan-Yi
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Ker, Ming-Dou
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A new architecture of charge pump circuit without suffering gate-oxide reliability in low-voltage CMOS processes is proposed, which is composed of two identical pumping branches and four-phase clock signals. The four-phase clock signals are designed to have no undesirable return-back leakage path during clock transition and to control the charge transfer MOSFET switches in the proposed circuit to be turned on and off completely. Therefore, its pumping efficiency is higher than that of the conventional one. Because the gate-to-source and gate-to-drain voltages of all devices in the new proposed charge pump circuit do not exceed the normal power supply voltage (VDD), the new proposed charge pump circuit is suitable for applications in low-voltage CMOS processes.
Carrier transportation mechanism of the TaN/HfO(2)/IL/Si structure with silicon surface fluorine implantation
(2008-07-01)
Wu, Woei Cherng
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Lai, Chao-Sung
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Wang, Tzu-Ming
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Wang, Jer-Chyi
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Hsu, Chih Wei
In this paper, the current transportation mechanism of HfO(2) gate dielectrics with a TaN metal gate and silicon surface fluorine implantation is investigated. Based on the experimental results of the temperature dependence of gate leakage current and Fowler-Nordheim tunneling characteristics at 77 K, we have extracted the current transport mechanisms and energy band diagrams for TaN/HfO(2)/IL/Si structures with fluorine incorporation, respectively. In particular, we have obtained the following physical quantities: 1) fluorinated and as-deposited interfacial layer (IL)/Si barrier heights (or conduction band offsets) at 3.2 and 2.7 eV; 2) TaN/fluorinated and as-deposited HfO(2) barrier heights at 2.6 and 1.9 eV; and 3) effective trapping levels at 1.25 eV (under both gate and substrate injections) below the HIM conduction band and at 1.04 eV (under gate injection) and 1.11 eV (under substrate injection) below the HfO(2) conduction band, which contributes to Frenkel-Poole conduction.
Design and Implementation of Capacitive Sensor Readout Circuit on Glass Substrate for Touch Panel Applications
(2011)
Wang, Tzu-Ming
;
Ker, Ming-Dou
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A capacitive sensor readout circuit on glass substrate for touch panel applications has been designed and fabricated in a 3-mu m low temperature poly-silicon (LTPS) technology. In this work, the small voltage difference from capacitance change due to the touch event on panel is amplified by the switch-capacitor (SC) technique. In order to reduce the effect from device characteristic variation in LTPS process, the proposed readout circuit applies the corrected double-sampling (CDS) technique to reduce the offset originated from LTPS process variation. To enhance the resolution of touch panel, a 4-bit analog-to-digital converter is utilized to identify the different touch area conditions.
Design and Implementation of Readout Circuit on Glass Substrate for Touch Panel Applications
(2010-08-01)
Wang, Tzu-Ming
;
Ker, Ming-Dou
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A readout circuit on glass substrate for touch panel application has been designed and fabricated in a 3-mu 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.
Design and implementation of readout circuit on glass substrate with digital correction for touch-panel applications
(2011-07-01)
Wang, Tzu-Ming
;
Ker, Ming-Dou
;
電機學院
;
電子工程學系及電子研究所
;
College of Electrical and Computer Engineering
A readout circuit on glass substrate with digital correction, which contains a transconductance amplifier, counter, and digital correction circuit, has been designed for touch-panel applications for 3-mu m low-temperature polysilicon (LTPS) technology. The voltage difference as a result of a change in capacitance due to a touch event is converted to current by a transconductance amplifier. By charging and discharging the capacitor in the counter, the counter displays different digital-output codes according to touch or non-touch events. Furthermore, not only can the touch or non-touch event be distinguished, but also the influence of LTPS process variation can be compensated by a digital correction circuit in the proposed readout circuit.
Design and Implementation of Readout Circuit with Threshold Voltage Compensation on Glass Substrate for Touch Panel Applications
(2011-03-01)
Lin, Yu-Ta
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Ker, Ming-Dou
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Wang, Tzu-Ming
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
A new on-panel readout circuit with threshold voltage compensation for capacitive sensor in low temperature polycrystalline silicon (poly-Si) thin-film transistor (LTPS-TFT) process has been proposed. In order to compensate the threshold voltage variation from LTPS process variation, the proposed readout circuit applies a novel compensation approach with switch capacitor technique. In addition, a 4-bit analog-to-digital converter ( ADC) is added to identify different sensed capacitor values and further enhances the overall resolution of touch panel. (c) 2011 The Japan Society of Applied Physics
Design of Analog Output Buffer With Level Shifting Function on Glass Substrate for Panel Application
(2009-09-01)
Wang, Tzu-Ming
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Ker, Ming-Dou
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Chen, Sao-Chi
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電機學院
;
College of Electrical and Computer Engineering
Two analog output buffers with level shifting function containing the digital-to-analog converter (DAC) circuit with gamma correction have been designed and verified in a 3-mu m low temperature poly-silicon (LTPS) technology, which are suitable for integrated on glass substrate for panel application. The new proposed circuits utilize the DAC with gamma correction of 3-V liquid crystal (LC) specification, but it can also drive the 5-V liquid crystal to meet the desired 5-V gamma curve without re-designing the DAC with 5-V gamma correction parameters.
Design of Mixed-Voltage-Tolerant Crystal Oscillator Circuit in Low-Voltage CMOS Technology
(2009-05-01)
Wang, Tzu-Ming
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Ker, Ming-Dou
;
Liao, Hung-Tai
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In the nanometer-scale CMOS technology, the gate-oxide thickness has been scaled down to provide higher operating speed with lower power supply voltage. However, regarding compatibility with the earlier defined standards or interface protocols of CMOS ICs in a microelectronics system, the chips fabricated in the advanced CMOS processes face the gate-oxide reliability problems in the interface circuits due to the voltage levels higher than normal supply voltage (1 x VDD) required by earlier applications. As a result, mixed-voltage I/O circuits realized with only thin-oxide devices had been designed with advantages of less fabrication cost and higher operating speed to communicate with the circuits at different voltage levels. In this paper, two new mixed-voltage-tolerant crystal oscillator circuits realized with low-voltage CMOS devices are proposed without suffering the gate-oxide reliability issues. The proposed mixed-voltage crystal oscillator circuits, which are one of the key I/O cells in a cell library, have been designed and verified in a 90-min 1-V CMOS process, to serve 1-V/2-V tolerant mixed-voltage interface applications.
Digital time-modulation pixel memory circuit in LTPS technology
(2011-08-01)
Chen, Szu-Han
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Ker, Ming-Dou
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Wang, Tzu-Ming
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A digital time-modulation pixel memory circuit on glass substrate has been designed and verified for a 3-mu m low-temperature polysilicon (LTPS) technology. From the experimental results, the proposed circuit can generate 4-bit digital codes and the corresponding inversion data with a time-modulation technique. While the liquid-crystal-display (LCD) panel operates in the still mode, which means the same image is displayed on the panel, a data driver for an LCD panel is not required to provide the image data of the frame by the proposed pixel memory circuit. This pixel memory circuit can store the frame data and generate its corresponding inversion data to refresh a static image without activating the data driver circuit. Therefore, the power consumption of a data driver can be reduced in the LCD panel.
Digital-to-analog converter with gamma correction on glass substrate for TFT-panel applications
(2009-10-01)
Wang, Tzu-Ming
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Li, Yu-Hsuan
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Ker, Ming-Dou
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Low-temperature polysilicon (LTPS) technology has a tendency towards integrating all circuits on glass substrate. However, the poly-Si TFTs suffered poor uniformity with large variations in the device characteristics due to a narrow laser process window for producing large-grained poly-Si TFTs. The device variation is a serious problem for circuit realization on the LCD panel, so how to design reliable on-panel circuits is a challenge for system-on-panel (SOP) applications. In this work, a 6-bit R-string digital-to-analog converter (DAC) with gamma correction on glass substrate for TFT-panel applications is proposed. The proposed circuit, which is composed of a folded R-string circuit, a segmented digital decoder, and reordering of the decoding circuit, has been designed and fabricated in a 3-mu m LTPS technology. The area of the new proposed DAC circuit is effectively reduced to about one-sixth compared to that of the conventional circuit for the same LTPS process.
Implementation of delta-sigma analog-to-digital converter in LTPS process
(2010-11-01)
Tsai, Chia-Chi
;
Wang, Tzu-Ming
;
Ker, Ming-Dou
;
電機學院
;
College of Electrical and Computer Engineering
An on-panel delta-sigma analog-to-digital converter (ADC) has been implemented and verified for 3-mu m low-temperature polysilicon (LTPS) technology with two basic blocks: a delta-sigma modulator and a decimation filter. From the experimental results, the digital output from the delta-sigma modulator is correctly matched with the analog input voltage ratio such that the digital output can be converted into 8-bit digital code successfully under a supply voltage of 10 V from the decimation filter. The implemented on-panel delta-sigma ADC can be used for the application of temperature-to-digital converter on glass substrate.
Implementation of delta-sigma analog-to-digital converter in LTPS process
(2010-11-01)
Tsai, Chia-Chi
;
Wang, Tzu-Ming
;
Ker, Ming-Dou
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
An on-panel delta-sigma analog-to-digital converter (ADC) has been implemented and verified for 3-mu m low-temperature polysilicon (LTPS) technology with two basic blocks: a delta-sigma modulator and a decimation filter. From the experimental results, the digital output from the delta-sigma modulator is correctly matched with the analog input voltage ratio such that the digital output can be converted into 8-bit digital code successfully under a supply voltage of 10 V from the decimation filter. The implemented on-panel delta-sigma ADC can be used for the application of temperature-to-digital converter on glass substrate.
Low-power wordline voltage generator for low-voltage flash memory
(2006)
Wang, Tzu-Ming
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Ker, Ming-Dou
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Yeh, Steve
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Chang, Ya-Chun
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電子工程學系及電子研究所
Wordline voltage generating circuit with high speed active mode and low power standby mode is proposed. In the active mode, two different ring oscillators with high clock frequency (f(CLK)) 170MHz, and low clock frequency (f(CLK)) 25MHz which is also the operating frequency of the entire circuit, are employed. The proposed circuit has a short response time of 3 mu s typically in active mode, and very low standby current about 3 mu A in standby mode.