Patent application number | Description | Published |
20080238539 | ARRANGEMENT FOR CANCELING OFFSET OF AN OPERATIONAL AMPLIFIER - Operational amplifier circuitry drives a device which may be run with a combination of output signals fewer in number than the output signals delivered from plural output circuits. Each output circuit adjusts the gain of an input signal supplied to its operational amplifier. An output selector selects and outputs output signals from the output circuits necessary for driving the device. A decision circuit compares an output signal not selected with a reference signal to adjust the gain of the output circuits to thereby cancel the offset of the operational amplifier. The operational amplifier has sets of feedback elements different in number between the sets formed by capacitances. Switching is made from one set to another until the decision circuit makes an acceptable decision. Offset may thus be canceled during the operational amplification even in case capacitive or resistance element is connected in circuit outside the operational amplifier. | 10-02-2008 |
20080303577 | ARRANGEMENT FOR CANCELING OFFSET OF DRIVER AMPLIFIER CIRCUITRY - In an offset canceling arrangement, an offset of an operational amplifier may be canceled even in case capacitive or resistive element is connected outside of the operational amplifier per se, and a signal may be output even during the offset canceling operation. IC chips include respective sets of plural output circuits. Each of the IC chips is provided with an offset canceling function, for which the respective sets of output circuits are grouped into plural groups. A reference signal for offset canceling is generated from a reference output circuit. One of the groups, each constituting one IC chip, is selected, and the reference signal for offset canceling generated by the group is used as a reference signal for offset canceling for the remaining group(s). | 12-11-2008 |
20090085788 | MULTI-INPUT OPERATIONAL AMPLIFIER CIRCUIT, DIGITAL/ANALOG CONVERTER USING SAME, AND DRIVER FOR DISPLAY DEVICE USING SAME - A multi-input operational amplifier circuit operable with a high degree of accuracy and in a small area, a D/A converter using the multi-input operational amplifier circuit, and a drive circuit or driver for a display device, using the D/A converter. In embodiments of the multi-input operational amplifier circuit, a constant current source of a third differential amplifier circuit that causes a doubled constant current i×2 to flow with respect to constant current sources of first and second differential amplifier circuits by application of two types of bias voltages thereto is configured using PMOS of the same number and size. Therefore, operations equivalent to those of a conventional circuit may be realized by the three constant current source PMOSs, and a smaller chip size may be required. | 04-02-2009 |
20100123704 | DISPLAY PANEL DRIVING APPARATUS - The present disclosure provides a display panel driving apparatus that can make the circuit layout surface area smaller, and prevent circuit damage. The display panel driving apparatus includes a source amplifier, a sink amplifier, a switch and the like. The source amplifier includes a first output circuit, a second output circuit and the like, and a guard transistor is provided between the first output circuit and the second output circuit to prevent an output signal voltage of the first output circuit from becoming less than an intermediate voltage. The sink amplifier includes a first output circuit and a second output circuit, and a guard transistor is provided between the first output circuit and the second output circuit to prevent an output signal voltage of the first output circuit from exceeding an intermediate voltage. | 05-20-2010 |
20100123705 | OPERATIONAL AMPLIFIER AND DISPLAY PANEL DRIVING DEVICE - An operational amplifier includes an output circuit and a differential circuit. The output circuit outputs a voltage in a voltage range determined either from a highest voltage that is an upper limit of a predetermined power source range, or from a lowest voltage that is a lower limit of the predetermined power source range, to an intermediate voltage that is a voltage between the highest voltage and the lowest voltage. The differential circuit includes a first MOS transistor to which a driving signal for driving a display panel is input and a second MOS transistor to which a given input signal is input. The first MOS transistor and the second MOS transistor are connected in parallel, and a differential input-permissible-range of the differential circuit is wider than the voltage range of the output circuit. | 05-20-2010 |
20100127378 | SEMICONDUCTOR DEVICE AND SEMICONDUCTOR PACKAGE - There is provided a semiconductor device including: plural bit cells each including the same circuit; plural electrodes supplied with power from outside, wherein each of the respective plural electrodes is mounted above the same circuit within the plural bit cells. Further, there is provided a semiconductor package including: the semiconductor device; a substrate mounted with the semiconductor device; an external input terminal formed on the substrate; an external output terminal formed on the substrate; an input wiring pattern connecting the semiconductor device mounted above the substrate and the external input terminal; an output wiring pattern connecting the semiconductor device mounted above the substrate and the external output terminal; and plural power supply lines, arranged without contact with each other on the same face of the substrate, and connecting the plural electrodes mounted to the semiconductor device to the corresponding electrode from the plural external power input electrodes. | 05-27-2010 |
20100127406 | SEMICONDUCTOR DEVICE - There is provided a semiconductor device including: plural first output pads formed along one edge of an outer periphery of a substrate; plural second output pads formed along at least one of an edge at an opposite side of the substrate from the one edge, and an edge adjoining the one edge; plural internal circuits, each of which is provided with an output terminal connected with an output pad of one of the first output pads and the second output pads; plural first lines, each of which connects one of the output terminals of the internal circuits with one of the plurality of first output pads; and plural second lines, each of which connects one of the output terminals of the internal circuits with one of the plural second output pads, resistance values per unit of wiring length being lower in the second lines than in the first lines. | 05-27-2010 |
20110157120 | DRIVE CIRCUIT AND DISPLAY DEVICE - A drive circuit for driving a display panel includes a first operation amplifier for operating using a first power source voltage and a second power source voltage; a second operation amplifier for operating using a third power source voltage and a fourth power source voltage; a control unit for supplying a first control voltage and a second control voltage; and a switch circuit for switching the first operation amplifier and the second operation amplifier. The switch circuit includes an n-channel type field effect transistor. The control unit applies the first control voltage to the n-channel type field effect transistor, so that the n-channel type field effect transistor transits from a non-conductive state to a conductive state. | 06-30-2011 |
20120001952 | DRIVING CIRCUIT AND DISPLAY APPARATUS - A driving circuit includes a pair of operational amplifiers, one producing an analog voltage output of positive polarity, the other producing an analog voltage output of negative polarity. An output switching circuit interchanges these outputs between a pair of data lines. One or both of the operational amplifiers includes a parasitic diode having one terminal connected to the output terminal of the operational amplifier and another terminal normally connected to a power supply voltage of the operational amplifier. When the output of the operational amplifier is switched, a protective switching circuit temporarily disconnects the parasitic diode from the power supply of the operational amplifier and instead connects it to a power supply line carrying a voltage high enough, or low enough, to ensure that the parasitic diode is not forward biased by the existing voltage on the data line to which the output is switched. | 01-05-2012 |
20140043221 | DEVICE CIRCUIT AND DISPLAY APPARATUS HAVING OPERATIONAL AMPLIFIERS WITH PARASITIC DIODES - A driving circuit includes a pair of operational amplifiers, one producing an analog voltage output of positive polarity, the other producing an analog voltage output of negative polarity. An output switching circuit interchanges these outputs between a pair of data lines. One or both of the operational amplifiers includes a parasitic diode having one terminal connected to the output terminal of the operational amplifier and another terminal normally connected to a power supply voltage of the operational amplifier. When the output of the operational amplifier is switched, a protective switching circuit temporarily disconnects the parasitic diode from the power supply of the operational amplifier and instead connects it to a power supply line carrying a voltage high enough, or low enough, to ensure that the parasitic diode is not forward biased by the existing voltage on the data line to which the output is switched. | 02-13-2014 |