Thin film transistor circuit and semiconductor display device using the same
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsShunpei Yamazaki, Jun Koyama
Life of this patent
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Abstract
There is provided a thin film transistor circuit used for a driver circuit for providing a semiconductor display device without a picture blur and with high fineness/high resolution. In the thin film transistor circuit, a TFT having a large size (channel width) is not used, but a plurality of TFTs each having a small size are connected in parallel to each other and are used. By this, while sufficient current capacity of the thin film transistors is secured, fluctuation in the characteristics can be decreased.
Claims30
A semiconductor device comprising at least:
- a differential circuit including x (x is a natural number not less than 2) input-side thin film transistors which have a common gate electrode potential and to which a signal is inputted, and x output-side thin film transistors which have a common gate electrode potential and from which a signal is outputted;
- and
- a current mirror circuit including y (y is a natural number not less than 2) input-side thin film transistors and y output-side thin film transistors, which have a common gate electrode potential, the gate electrodes of y input-side thin film transistors being connected to sources/drains of y input-side thin film transistors.
A semiconductor device comprising at least:
- a differential circuit including x (x is a natural number not less than 2) input-side thin film transistors which have a common gate electrode potential and to which a signal is inputted, and (n n x) (n is a natural number not less than 2) output-side thin film transistors which have a common gate electrode potential and from which a signal is outputted;
- and
- a current mirror circuit including y (y is a natural number not less than 2) input-side thin film transistors and (n n y) output-side thin film transistors, which have a common gate electrode potential, the gate electrodes of y input-side thin film transistors being connected to source/drain regions of y input-side thin film transistors.
A semiconductor device comprising:
- a pixel matrix region;
- and
- a driver circuit comprising at least a thin film transistor circuit, the thin film transistor circuit comprising:
- a differential circuit including x (x is a natural number not less than 2) input-side thin film transistors which have a common gate electrode potential and to which a signal is inputted, and x output-side thin film transistors which have a common gate electrode potential and from which a signal is outputted;
- and a current mirror circuit including y (y is a natural number not less than 2) input-side thin film transistors and y output-side thin film transistors, which have a common gate electrode potential, the gate electrodes of y input-side thin film transistors being connected to source/drain regions of y input-side thin film transistors,
- wherein the pixel matrix region and the driver circuit are formed on the same substrate.
A semiconductor device comprising:
- a pixel matrix region;
- and
- a driver circuit comprising at least a thin film transistor circuit, the thin film transistor circuit comprising at least:
- a differential circuit including x (x is a natural number not less than 2) input-side thin film transistors which have a common gate electrode potential and to which a signal is inputted, and (n n x) (n is a natural number not less than 2) output-side thin film transistors which have a common gate electrode potential and from which a signal is outputted;
- and a current mirror circuit including y (y is a natural number not less than 2) input-side thin film transistors and (n×y) output-side thin film transistors, which have a common gate electrode potential, the gate electrodes of y input-side thin film transistors are connected to source/drain regions of y input-side thin film transistors,
- wherein the pixel matrix region and the driver circuit are formed on the same substrate.
A semiconductor device comprising a pixel matrix region and a driver circuit having at least one buffer circuit, said buffer circuit comprising:
- a differential circuit having x input-side thin film transistors connecting in parallel to each other (x≧2, x is natural number) and n×x output-side thin film transistors connecting in parallel to each other (n≧1, n is natural number), and
- a current mirror circuit having y input-side thin film transistors connecting in parallel to each other (y≧2, y is natural number) and n×y output-side thin film transistors connecting in parallel to each other (n≧1, n is natural number).
A semiconductor device comprising a pixel matrix region and a driver circuit having at least one buffer circuit, said buffer circuit comprising:
- a differential circuit having a plurality of thin film transistors connecting in parallel to each other and dividing an input into x and a plurality of thin film transistors connecting in parallel to each other and dividing an output into n×x (n≧1, n is natural number), respectively, and
- a current mirror circuit having a plurality of thin film transistors connecting in parallel to each other and dividing an input into y and a plurality of thin film transistors connecting in parallel to each other and dividing an output into n×y (n≧1, n is natural number), respectively.
Dependencies are inferred from the claim text.