摘要:
When a potential of a power supply line varies according to a flowing current, the gate-source voltage Vgs of a transistor also varies, leading to variations in the constant current between each source follower. In order to solve this problem, a potential Vb of the gate terminal of a transistor as a constant current source is changed in the same manner as a power supply line Vss which is connected to the source terminal of the transistor. Therefore, variations in the constant current are suppressed and variations in the output of the source followers are thus suppressed. In addition, by connecting the circuit having source followers to the output side of a signal line driver circuit, it can be prevented that luminance unevenness of a striped pattern is recognized in a display portion of a semiconductor device.
摘要:
A source follower in which any one of the following three modes is selected by a plurality of switching elements: a first mode in which a first potential is supplied to a gate of a transistor and an input potential is supplied to a first electrode of a capacitor respectively and a second electrode of the capacitor and a source of the transistor are connected, a second mode in which an input potential is supplied to the first electrode and the gate of the transistor and the second electrode floats, and a third mode in which the first electrode and the gate of the transistor are connected and a potential thereof floats and a second potential is supplied to the second electrode, a drain of the transistor is supplied with a third potential, and a potential of the source of the transistor is supplied to a subsequent circuit.
摘要:
A liquid crystal display device having analog buffer circuits, which is reduced in luminance fluctuation is provided. A source signal line driver circuit has a plurality of analog buffer circuits, the plurality of source signal lines and the plurality of analog buffer circuits constitute a circuit group, and source signal lines connected to the analog buffer circuits are switched their connections to different analog buffer circuits each time a new period is started. Therefore, output fluctuation among the analog buffer circuits is averaged and a uniform image can be displayed on the screen.
摘要:
A circuit with a large load driving capability, which is structured by single polarity TFTs, is provided. With a capacitor (154) formed between a gate electrode and an output electrode of a TFT (152), the electric potential of the gate electrode of the TFT (152) is increased by a boot strap and normal output with respect to an input signal is obtained without amplitude attenuation of an output signal due to the TFT threshold value. In addition, a capacitor (155) formed between a gate electrode and an output electrode of a TFT (153) compensates for increasing the electric potential of the gate electrode of the TFT (152), and a larger load driving capability is obtained.
摘要:
When a potential of a power supply line varies according to a flowing current, the gate-source voltage Vgs of a transistor also varies, leading to variations in the constant current between each source follower. In order to solve this problem, a potential Vb of the gate terminal of a transistor as a constant current source is changed in the same manner as a power supply line Vss which is connected to the source terminal of the transistor. Therefore, variations in the constant current are suppressed and variations in the output of the source followers are thus suppressed. In addition, by connecting the circuit having source followers to the output side of a signal line driver circuit, it can be prevented that luminance unevenness of a striped pattern is recognized in a display portion of a semiconductor device.
摘要:
A driver circuit of a display device, which includes TFTs of a single conductivity type and outputs an output signal with normal amplitude. A pulse is inputted to TFTs 101 and 104 to turn ON the TFTs and a potential of a node &agr; is raised. When the potential of the node &agr; reaches (VDD−VthN), the node &agr; becomes in a floating state. Accordingly, a TFT 105 is turned ON and a potential of an output node is raised as a clock signal becomes High level. On the other hand, a potential of a gate electrode of the TFT 105 is further raised due to an operation of a capacitance means 107 as the potential of the output node is raised, so that the potential of the gate electrode of the TFT 105 becomes higher than (VDD+VthN). Thus, the potential of the output node is raised to VDD without causing a voltage drop due to a threshold voltage of the TFT 105. An output at the subsequent stage is then inputted to a TFT 103 to turn the TFT 103 On, while the potential of the node &agr; of TFTs 102 and 106 is dropped to turn the TFT 105 OFF. As a result, the potential of the output node becomes Low level.
摘要:
An object of the present invention is to provide a semiconductor device which can obtain the high potential necessary for writing data to a memory, using a small circuit area. In the present invention, by using as input voltage of a booster circuit not the conventionally used output VDD of a regulator circuit 104, but rather an output VDD0 of a rectifier circuit portion 103, which is a higher potential than the VDD, the high potential necessary for writing data to a memory can be obtained with a small circuit area.
摘要:
A sense amplifier according to the present invention for detecting a potential difference of signals input to a first input terminal and a second input terminal, includes a first means for applying voltages corresponding to threshold voltages of first and second transistors to gate-source voltages of the first and second transistors, and a second means for transferring signals input to the first and second input terminals to gates of the first and second transistors. In this case, a threshold variation of the first and second transistors is corrected.
摘要:
According to the invention, mounting area is decreased and yield is improved by decreasing the number of elements, and a memory with less burden on peripheral circuitry and a driving method thereof are provided. The invention comprises a memory cell including a memory element in a region where a bit line and a word line cross with an insulator interposed between them, a column decoder, and a selector including a clocked inverter. An input node of the clocked inverter is connected to the bit line while an output node is connected to a data line. Among a plurality of transistors connected in series which form the clocked inverter, a gate of a P-type transistor of which source or drain is connected to a power source on the high potential side VDD and a gate of an N-type transistor of which source or drain is connected to a power source on the low potential side VSS are connected to the column decoder.
摘要:
A sense amplifier according to the present invention for detecting a potential difference of signals input to a first input terminal and a second input terminal, includes a first means for applying voltages corresponding to threshold voltages of first and second transistors to gate-source voltages of the first and second transistors, and a second means for transferring signals input to the first and second input terminals to gates of the first and second transistors. In this case, a threshold variation of the first and second transistors is corrected.