Patent application number | Description | Published |
20110089419 | SEMICONDUCTOR DEVICE - An object is to provide a memory device including a memory element that can be operated without problems by a thin film transistor with a low off-state current. Provided is a memory device in which a memory element including at least one thin film transistor that includes an oxide semiconductor layer is arranged as a matrix. The thin film transistor including an oxide semiconductor layer has a high field effect mobility and low off-state current, and thus can be operated favorably without problems. In addition, the power consumption can be reduced. Such a memory device is particularly effective in the case where the thin film transistor including an oxide semiconductor layer is provided in a pixel of a display device because the memory device and the pixel can be formed over one substrate. | 04-21-2011 |
20110115545 | SEMICONDUCTOR DEVICE - An object is to provide a semiconductor device that can realize a function of a thyristor without complication of the process. A semiconductor device including a memory circuit that stores a predetermined potential by reset operation and initialization operation is provided with a circuit that rewrite data in the memory circuit in accordance with supply of a trigger signal. The semiconductor device has a structure in which a current flowing through the semiconductor device is supplied to a load by rewriting data in the memory circuit, and thus can function as a thyristor. | 05-19-2011 |
20120056646 | SEMICONDUCTOR DEVICE AND METHOD FOR DRIVING THE SAME - An object is to alleviate the concentration of an electric field in a semiconductor device. A gate electrode and a drain electrode are provided not to overlap with each other, and an electric-field control electrode is provided between the gate electrode and the drain electrode over a top surface. Insulating layers are provided between the gate electrode and a semiconductor layer and between the electric-field control electrode and the semiconductor layer, and the insulating layer provided between the electric-field control electrode and the semiconductor layer has a larger thickness than the insulating layer provided between the gate electrode and the semiconductor layer. Further, when the semiconductor device is driven, the potential of the electric-field control electrode may be higher than or equal to a source potential and lower than a gate potential, and for example, connection between the electric-field control electrode and the source potential enables such a structure. | 03-08-2012 |
20120056863 | Oscillator Circuit and Semiconductor Device Using the Oscillator Circuit - The oscillator circuit includes a comparator circuit which compares a potential supplied to one of input terminals with a potential supplied to the other of the input terminals and outputs a high power supply potential or a low power supply potential, a capacitor which is electrically connected to the one of the input terminals of the comparator circuit, and a charge and discharge circuit which charges and discharges the capacitor. The charge and discharge circuit includes a first current supply circuit and a second current supply circuit. Each of a current value of the first current supply circuit and a current value of the second current supply circuit can be controlled with the use of a digital control signal. | 03-08-2012 |
20120075007 | REFERENCE CURRENT GENERATING CIRCUIT, REFERENCE VOLTAGE GENERATING CIRCUIT, AND TEMPERATURE DETECTION CIRCUIT - A reference current generating circuit with high current mirror accuracy is provided by low power supply voltage operation. The reference current generating circuit includes a cascode current mirror circuit | 03-29-2012 |
20120274401 | SEMICONDUCTOR DEVICE AND METHOD FOR DRIVING THE SAME - An object is to suppress operation delay caused when a semiconductor device that amplifies and outputs an error between two potentials returns from a standby mode. Electrical connection between an output terminal of a transconductance amplifier and one electrode of a capacitor is controlled by a transistor whose channel is formed in an oxide semiconductor layer. Consequently, turning off the transistor allows the one electrode of the capacitor to hold charge for a long time even if the transconductance amplifier is in the standby mode. Moreover, when the transconductance amplifier returns from the standby mode, turning on the transistor makes it possible to settle charging and discharging of the capacitor in a short time. As a result, the operation of the semiconductor device can enter into a steady state in a short time. | 11-01-2012 |
20120293223 | PHASE LOCKED LOOP AND SEMICONDUCTOR DEVICE USING THE SAME - It is an object of the present invention to provide a phase locked loop in which a voltage signal input to a voltage controlled oscillator after a return from a stand-by state becomes constant in a short time and power consumption is reduced. A transistor including a semiconductor layer formed using an oxide semiconductor material is provided between an input terminal of a voltage controlled oscillator and a capacitor of a loop filter. The transistor is turned on in a normal operation state and turned off in a stand-by state. | 11-22-2012 |
20130056763 | SEMICONDUCTOR DEVICE - An object is to provide a semiconductor device that can realize a function of a thyristor without complication of the process. A semiconductor device including a memory circuit that stores a predetermined potential by reset operation and initialization operation is provided with a circuit that rewrite data in the memory circuit in accordance with supply of a trigger signal. The semiconductor device has a structure in which a current flowing through the semiconductor device is supplied to a load by rewriting data in the memory circuit, and thus can function as a thyristor. | 03-07-2013 |
20130162238 | REFERENCE POTENTIAL GENERATION CIRCUIT - A reference potential generation circuit is provided. The reference potential generation circuit includes first to third input terminals, first and second output terminals, a low-pass filter including first to third terminals, and a linear regulator including first to fourth terminals. In the reference potential generation circuit, the first terminal of the low-pass filter is electrically connected to the second input terminal. The second terminal of the low-pass filter is electrically connected to the first input terminal or the third input terminal The third terminal of the low-pass filter is electrically connected to the first terminal of the linear regulator. The second terminal of the linear regulator is electrically connected to the first input terminal and the first output terminal. The third terminal of the linear regulator is electrically connected to the second output terminal. The fourth terminal of the linear regulator is electrically connected to the third input terminal. | 06-27-2013 |
20130162305 | SEMICONDUCTOR DEVICE, IMAGE DISPLAY DEVICE, STORAGE DEVICE, AND ELECTRONIC DEVICE - To provide a semiconductor device with reduced power consumption that includes a selection transistor. To provide a semiconductor device capable of high-speed operation without increasing a power supply potential. A buffer circuit connected to a gate line has a function of generating a potential higher than a high power supply potential by using the high power supply potential and outputs the potential in response to a selection signal. Specifically, a bootstrap circuit boosts a high power supply potential that is input to an inverter that is the closest to an output side in the buffer circuit. Further, the bootstrap circuit boosts the potential when the gate line is selected, and does not boost the potential when the gate line is not selected. | 06-27-2013 |
20130162609 | DISPLAY DEVICE - To provide a display device with high image quality and fewer terminals. The present invention is made with a focus on the positional relation between a serial-parallel conversion circuit and an external connection terminal for supplying a serial signal to the serial-parallel conversion circuit. The structure conceived is such that a serial-parallel conversion circuit and an external connection terminal for supplying a serial signal to the serial-parallel conversion circuit are provided close to each other so that an RC load between the serial-parallel conversion circuit and the external connection terminal is reduced | 06-27-2013 |
20130162613 | Signal Converter Circuit, Display Device, and Electronic Device - To suppress an adverse effect of change in held data in a sample-and-hold circuit as a result of increase in operation speed on a generated parallel data signal. A signal converter circuit includes a first sample-and-hold circuit and a second sample-and-hold circuit each of which has a function of extracting and holding part of a serial data signal as a data in accordance with a sampling control signal and has a function of generating a data signal which is one of data signals of a parallel data signal by using the held data and outputting the data signal. The second sample-and-hold circuit includes a switch which has a function of selecting whether the potential of the data of the second sample-and-hold circuit is set to a reference potential or not in accordance with the sampling control signal of the first sample-and-hold circuit. | 06-27-2013 |
20130207945 | Display Device - A display device with fewer terminals. The display device includes a timing signal generating circuit which outputs an output signal based on a clock signal, in which one signal line serves as both a signal line to which a start pulse signal that drives the timing signal generating circuit is input and a signal line to which an image signal is input. Further, a blocking circuit which outputs a start pulse to the timing signal generating circuit but does not output the image signal is provided between the signal line and the timing signal generating circuit. | 08-15-2013 |
20130307496 | SEMICONDUCTOR DEVICE AND DRIVING METHOD THEREOF - One object of the invention is to reduce discharge of electric charge from a capacitor when supply of power supply voltage to a charge pump circuit is stopped and restarted, so that a time required after the supply of power supply voltage is restarted and before an input signal is boosted is shortened. A semiconductor device includes a boosting circuit portion including a charge transfer element and a capacitor, boosting a voltage level of an input signal, and outputting an output signal having a boosted voltage level; a detection circuit monitoring a voltage level of the output signal; and a control circuit outputting a signal for controlling boosting of the voltage level of the input signal to the boosting circuit portion in accordance with the voltage level obtained by the detection circuit. The boosting circuit portion includes a switch electrically connected to the capacitor and the charge transfer element. | 11-21-2013 |
20140021904 | CHARGING DEVICE - A charging device used for charging a storage battery includes a first circuit that generates a current which depends on a charging current of the storage battery; a second circuit in which charge is accumulated by periodical supply of the current which depends on the charging current; and a third circuit that outputs a signal indicating completion of charge of the storage battery when the potential of the second circuit reaches a reference potential. The second circuit includes a capacitor and a transistor in which an oxide semiconductor is used for a channel formation region. The transistor is turned on or off in response to a pulse signal input to a gate of the transistor. The capacitor accumulates charge when the current depending on the charging current flows through the transistor. | 01-23-2014 |
20140068301 | Semiconductor Device and Electronic Device - To reduce a variation in the electrical characteristics of a transistor. A potential generated by a voltage converter circuit is applied to a back gate of a transistor included in a voltage conversion block. Since the back gate of the transistor is not in a floating state, a current flowing through the back channel can be controlled so as to reduce a variation in the electrical characteristics of the transistor. Further, a transistor with low off-state current is used as the transistor included in the voltage conversion block, whereby storage of the output potential is controlled. | 03-06-2014 |
20140247093 | PHASE LOCKED LOOP AND SEMICONDUCTOR DEVICE USING THE SAME - It is an object of the present invention to provide a phase locked loop in which a voltage signal input to a voltage controlled oscillator after a return from a stand-by state becomes constant in a short time and power consumption is reduced. A transistor including a semiconductor layer formed using an oxide semiconductor material is provided between an input terminal of a voltage controlled oscillator and a capacitor of a loop filter. The transistor is turned on in a normal operation state and turned off in a stand-by state. | 09-04-2014 |
20140337603 | SEMICONDUCTOR DEVICE - An object is to provide a memory device including a memory element that can be operated without problems by a thin film transistor with a low off-state current. Provided is a memory device in which a memory element including at least one thin film transistor that includes an oxide semiconductor layer is arranged as a matrix. The thin film transistor including an oxide semiconductor layer has a high field effect mobility and low off-state current, and thus can be operated favorably without problems. In addition, the power consumption can be reduced. Such a memory device is particularly effective in the case where the thin film transistor including an oxide semiconductor layer is provided in a pixel of a display device because the memory device and the pixel can be formed over one substrate. | 11-13-2014 |
20150054571 | CHARGE PUMP CIRCUIT AND SEMICONDUCTOR DEVICE INCLUDING THE SAME - Efficiency of a charge pump circuit is increased. The charge pump circuit includes serially connected fundamental circuits each including a diode-connected transistor and a capacitor. At least one transistor is provided with a back gate, and the back gate is connected to any node in the charge pump circuit. For example, the charge pump circuit is of a step-up type; in which case, if the transistor is an n-channel transistor, a back gate of the transistor in the last stage is connected to an output node of the charge pump circuit. Back gates of the transistors in the other stages are connected to an input node of the charge pump circuit. In this way, the voltage holding capability of the fundamental circuit in the last stage is increased, and the conversion efficiency can be increased because an increase in the threshold of the transistors in the other stages is prevented. | 02-26-2015 |