摘要:
An operational amplifier generates a power supply potential from a reference potential. An impedance adjuster adjusts an output impedance of the operational amplifier in accordance with a control signal. A charge accumulator accumulates an output charge of the operational amplifier whose impedance is adjusted by the impedance adjuster. A comparator compares an output voltage of the operational amplifier before the impedance adjustment by the impedance adjuster and the output voltage of the operational amplifier after the impedance adjustment by the impedance adjuster to each other, and the comparator further generates the control signal in accordance with a result of the comparison so as to output the generated control signal to the impedance adjuster.
摘要:
A regulator for generating, from a first power supply voltage exceeding the breakdown voltage of a low voltage transistor block, a second power supply voltage lower than or equal to the breakdown voltage of the low voltage transistor block, includes an operational amplifier including low voltage transistors and high voltage transistors. An operational amplifier including only low voltage transistors can be employed.
摘要:
The present invention is provided with a plural cell including a transistor pair. The plural cells are arranged at equal intervals so as to configure a cell group. A inter-cell distance between a transistor in one of the cell and a transistor the other cell in each of adjacent cells in the cell group is equal to a intra-cell distance between one of the transistor and the other transistor in the transistor pair.
摘要:
A control unit performs the first-third controls. The first control controls a group of switch elements so that a step-up voltage is supplied to a voltage output terminal by a pumping action of a step-up voltage accumulating capacity element by applying the reference power source voltage to the reference power source voltage accumulating capacity element in an inverse direction, after execution of an electric charge accumulating action with the reference power source voltage in the reference power source voltage accumulating capacity element. The second control controls the group of switching elements so as to provide a dead-time period, during which the reference power source and the reference power source voltage accumulating element are disconnected, between a period of the electric charge accumulating action and a period of the pumping action and between the period of pumping action and the period of electric charge accumulating action. The third control achieves such a control in the first and second step-up circuit units alternately and cyclically that the electric charge accumulating action or the pumping action in one of the first and second step-up circuit units is carried out, when the other is in the dead-time period.
摘要:
A compact-size driving voltage controller is provided which can be driven with low power. The compact-size driving voltage controller which can be driven with low power includes a High output operational amplifier and a Low output operational amplifier for supplying driving voltages VcomH, VcomL to a load such as a liquid crystal display panel, an output switch for alternating between the outputs of the operational amplifiers, a Low voltage setting operational amplifier for generating a set voltage to be supplied to the non-inverted input terminal of the Low output operational amplifier, a set voltage generator including a current mirror circuit and a clamping circuit, a bias current controller for controlling the bias current flowing in each operational amplifier with a predetermined timing, and a timing controller for controlling the changeover timing of the output switch.
摘要:
A driving voltage control device includes: a first differential amplifier circuit for receiving a first input voltage and outputting a first output voltage; a second differential amplifier circuit for receiving a second input voltage and outputting a second output voltage; a control section for selecting one of a first mode and a second mode; and an output section for supplying the first output voltage output from the first differential amplifier circuit to an output node when the first mode is selected by the control section and supplying the second output voltage output from the second differential amplifier circuit to the output node when the second mode is selected by the control section. When the first mode is selected, the control section increases a driving power of the first differential amplifier circuit.
摘要:
A liquid crystal display device according to the present invention includes: a liquid crystal panel 11; a source driver 12 for controlling the gray-scale level by applying a voltage to the liquid crystal panel 11; a DC-DC power supply 13 for driving the source driver 12 by supplying current to the source driver 12; a controller 14 for supplying a signal for controlling the gray-scale level to the source driver 12; and a variation calculator 15 for calculating the amount of change in the signal from the controller 14. In the DC-DC power supply 13, current to be supplied to the source driver 12 changes in accordance with the amount of change in the signal calculated by the variation calculator 15.
摘要:
A driving voltage output circuit is provided for selectively outputting a positive driving voltage and a negative driving voltage. The driving voltage includes: an amplifier which amplifies and outputs, as a driving voltage, a selectively input positive or negative input signal; and a power supply voltage switching circuit which switches a power supply voltage to be supplied to the amplifier according to a polarity of the input signal.
摘要:
A regulator for generating, from a first power supply voltage exceeding the breakdown voltage of a low voltage transistor block, a second power supply voltage lower than or equal to the breakdown voltage of the low voltage transistor block, includes an operational amplifier including low voltage transistors and high voltage transistors. An operational amplifier including only low voltage transistors can be employed.
摘要:
In an offset cancellation circuit according to the present invention, a first capacitance is connected to a gate of a first transistor of a first active load, and a second capacitance is connected to a gate of a second transistor of the first active load. A switch sets a first time period and a second time period in connection states between the first and second transistors and the first and second capacitances. The connection states between the first and second transistors and the first and second capacitances are set so that a gate voltage of the first transistor is supplied to the first capacitance, and a gate voltage of the second transistor is supplied to the second capacitance during the first time period; and so that the first and second capacitances can retain charges, and the second time period becomes an output time period of the operational amplifier during the second time period.