Apparatus comprising analog to digital converter semiconductor device
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsTakuro Kanemura, Yoshiyuki Kurokawa, Hiromichi Godo, Kazuki Tsuda, Satoru Ohshita, Hidefumi Rikimaru
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Abstract
A novel semiconductor device is provided. An analog signal is converted into a digital signal using a comparison portion comparing two current values, a control portion, and a current output digital-analog conversion portion. The control portion has a function of generating a sign bit showing a magnitude relation between the two current values, a function of converting a difference between the two current values into a digital signal by successive approximation, and a function of outputting the sign bit and the digital signal.
Claims16
A semiconductor device comprising:
- a current comparator having a first input terminal, a second input terminal, and an output terminal;
- a first DA converter (Digital to Analog converter) having an output terminal electrically connected to the first input terminal of the current comparator;
- a second DA converter having an output terminal electrically connected to the second input terminal of the current comparator;
- and
- a control portion electrically connected to the output terminal of the current comparator, the first DA converter, and the second DA converter,
- wherein the current comparator is configured to compare a value of a first current flowing to the first input terminal with a value of a second current flowing to the second input terminal and supply one of a first potential and a second potential as an output signal to the output terminal of the current comparator,
- wherein the control portion is configured to generate a digital signal and a sign bit in accordance with the output signal, supply the digital signal to the first DA converter and the second DA converter, and generate a signed digital signal by adding the sign bit and the digital signal,
- wherein the first DA converter is configured to flow a third current in accordance with the digital signal to the first input terminal of the current comparator, and
- wherein the second DA converter is configured to flow a fourth current in accordance with the digital signal to the second input terminal of the current comparator.
A semiconductor device comprising:
- a current comparator having a first input terminal, a second input terminal, and an output terminal;
- a first DA converter (Digital to Analog converter) having an output terminal electrically connected to the first input terminal of the current comparator;
- a second DA converter having an output terminal electrically connected to the second input terminal of the current comparator;
- and
- a control portion electrically connected to the output terminal of the current comparator, the first DA converter, and the second DA converter,
- wherein the current comparator is configured to compare a value of a first current flowing to the first input terminal with a value of a second current flowing to the second input terminal and supply one of a first potential and a second potential as an output signal to the output terminal of the current comparator,
- wherein the control portion is configured to generate a digital signal and a sign bit in accordance with the output signal, supply the digital signal to the first DA converter and the second DA converter, generate a signed digital signal by combining the digital signal and the sign bit, and output the signed digital signal,
- wherein the first DA converter is configured to flow a third current in accordance with the digital signal to the first input terminal of the current comparator, and
- wherein the second DA converter is configure to flow a fourth current in accordance with the digital signal to the second input terminal of the current comparator.
Dependencies are inferred from the claim text.