摘要:
A digital-to-analog converter includes a first converter stage 1 for converting the m most significant bits of a k bit input signal to upper and lower voltage limits VL and VH by selecting the appropriate low impedance reference voltages. A second converter stage 2 performs a linear conversion of the n least significant bits of the k bit input within the voltage range defined by the voltage limits VL and VH. A precharging circuit including switches SW1 and SW2 disconnects the stage 2 from the load CLOAD, which is charged to the voltage limit VL during the precharge phase. The load is subsequently disconnected from the voltage limit VL and connected to the output of the stage 2 to complete charging of the load CLOAD to the converter output voltage.
摘要:
An active matrix devise comprises an array of picture elements. Each picture element has an image element, such as an LCD cell (11) connected to a first storage capacitor 12 and arranged to be connected to a data line 4 by an thin film transistor 10 when activated by a scan signal on a scan line 6. A second storage capacitor 21 can be connected across the first capacitor 12 by means of another thin film transistor 20 when desired so as to increase the storage capacitance at the pixel.
摘要:
There are provided: a first logic operation circuit which performs a logic operation using a high-amplitude logic signal; a transmission system having a load capacitance; and a low-voltage signal generator which is a step-down level shifter transforming an incoming high-amplitude logic signal from the first logic operation circuit to a low-amplitude logic signal having a lower amplitude than the high-amplitude logic signal for output to the transmission system. In the configuration, the first logic operation circuit operates based on a high-amplitude logic signal, and is therefore free from malfunctions and performs operations at high speed. Further, the transmission system introducing a load capacitance transmits a low-amplitude logic signal and therefore restrains increases in electric power consumption and occurrence of unnecessary radiation.
摘要:
There are provided: a first logic operation circuit which performs a logic operation using a high-amplitude logic signal; a transmission system having a load capacitance; and a low-voltage signal generator which is a step-down level shifter transforming an incoming high-amplitude logic signal from the first logic operation circuit to a low-amplitude logic signal having a lower amplitude than the high-amplitude logic signal for output to the transmission system. In the configuration, the first logic operation circuit operates based on a high-amplitude logic signal, and is therefore free from malfunctions and performs operations at high speed. Further, the transmission system introducing a load capacitance transmits a low-amplitude logic signal and therefore restrains increases in electric power consumption and occurrence of unnecessary radiation.
摘要:
There are provided: a first logic operation circuit which performs a logic operation using a high-amplitude logic signal; a transmission system having a load capacitance; and a low-voltage signal generator which is a step-down level shifter transforming an incoming high-amplitude logic signal from the first logic operation circuit to a low-amplitude logic signal having a lower amplitude than the high-amplitude logic signal for output to the transmission system. In the configuration, the first logic operation circuit operates based on a high-amplitude logic signal, and is therefore free from malfunctions and performs operations at high speed. Further, the transmission system introducing a load capacitance transmits a low-amplitude logic signal and therefore restrains increases in electric power consumption and occurrence of unnecessary radiation.
摘要:
An image display device includes two data signal line drive circuits and two scan signal line drive circuits configured differently from each other. Different data signal line drive circuits and scan signal line drive circuit are compatible with different display formats. A display can be produced in the most suitable display format, and power consumption also can be reduced, by switch operating drive circuits according to the kind of input video and environmental conditions. Further, an image can be written over another image by writing video signals to signal lines with a time lag using a plurality of drive circuits; therefore, a superimposed display can be produced without externally processing the video signals. Thus, both a satisfactory image display and low power consumption can be achieved in an image display device.
摘要:
A level shifter 13 is provided for each of SR flip flops F1 constituting a shift register 11. The level shifter 13 increases a voltage of a clock signal CK. This arrangement reduces a distance for transmitting a clock signal whose voltage has been increased, as compared with a construction in which a voltage of a clock signal is increased by a single level shifter and the signal is transmitted to each of the flip flops; consequently, a load capacity of the level shifter can be smaller. Furthermore, each of the level shifters is operated during a pulse output of the previous level shifter 13, and the operation is suspended at the end of the pulse output. Thus, the level shifters 13 can operate only when it is necessary to apply a clock signal CK to the corresponding SR flip flop F1. As a result, even when an amplitude of a clock signal is small, it is possible to reduce power consumption of the shift resister under normal operation.
摘要:
A signal line driving circuit includes a shift register having a plurality of shift circuits, each of which shifts a start pulse successively to the next stage, synchronizing with the timing of a clock signal. In this signal line driving circuit, shift pulses are outputted from an AND gate based on output pulses of two adjacent shift circuits. Meanwhile, a width specifying pulse for specifying a pulse width of the shift pulse is inputted via a transistor whose ON/OFF operation is controlled by the shift pulse. A logical operation circuit operates an AND of the shift pulse and the width specifying pulse and outputs the result of operation to a signal line. When the shift pulse is non-active, the transistor becomes OFF, which causes the signal line transmitting the width specifying pulse to be disconnected from the signal line driving circuit, thereby reducing a capacitive load of wiring. As a result, reduction of a parasitic capacitance of the wiring, reduction in the number of elements, reduction in the size of an amplitude of an input signal, etc. in the signal line driving circuit are attained.
摘要:
A shift register is provided with a shift register section composed of a plurality of stages of flip-flops that operate in synchronization with a clock signal, and level shifters for boosting a start signal lower than a driving voltage and for applying the same to both ends of the shift register section, and the shift register is capable of switching the shift direction in accordance with the switching signal. The foregoing level shifters are current-driving-type level shifters that can operate even in the case where the transistor characteristics are inferior or in the case of fast operations, and that can carry out level shifting even with a start signal having a small amplitude. Furthermore, the foregoing level shifters are provided at both ends of the shift register section, respectively, and one of the same stops operating in accordance with a switching signal, so that consumed power should decrease. Consequently, there can be provided a shift register that is capable of shifting in two directions, that can normally operate even with an input signal having a small amplitude, and that therefore consumes less electric power.
摘要:
A voltage level shifter comprises complementary transistors T1, T2 connected between a supply line vdd and an inverting input !IN. The gates of the transistors T1 and T2 receive a shifted version of the direct input signal IN from a source-follower comprising the transistors T3 and T4.