D/A conversion circuit having n switches, n capacitors and a coupling capacitor
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorYukio Tanaka
Life of this patent
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Abstract
A D/A conversion circuit is described which comprises a n switching, n capacitors and a coupling circuit. Upper n bit of the digital signal control n switches respectively and control charging and discharging of electric charge into the n capacitors, and the n capacitors are connected to the output line in an upper bit writing period. Lower n bit of the digital signal control the n switches and control charging and discharging of electric charge into the n capacitors, and the capacitors are connected to the output line through the coupling capacitor in a lower bit writing period.
Claims9
A semiconductor device which comprises a source signal line driver circuit, a gate signal line driver circuit and a pixel section, wherein the source signal line driver circuit comprises a D/A converter circuit which converts a 2n bit digital signal into an analog signal, which comprises n switches, n capacitors and a coupling capacitor, where n is a natural number, wherein:
- upper n bit of the digital signal control n switches respectively and control charging and discharging of electric charge into said n capacitors and said n capacitors are connected to the output line in an upper bit writing period;
- and
- lower n bit of the digital signal control said n switches and control charging and discharging of electric charge into said n capacitors and said n capacitors are connected to said output line through said coupling capacitor in a lower bit writing period.
A semiconductor device which comprises a source signal line driver circuit, a gate signal line driver circuit and a pixel section, wherein the source signal line driver circuit comprises a D/A converter circuit which converts 2n bit digital signal into analog signal, which comprises n switches, n capacitors and a coupling capacitor, where n is a natural number, wherein:
- in a first period, one electrode among 2 electrodes which comprise each of said n capacitors is connected to a first power source and the other electrode is connected to a third power source;
- in a second period, upper n bit of said digital signal respectively control n switches and said one electrode is connected to said first power source or a second power source and said other electrode is connected to an output line;
- in a third period, said one electrode is connected to the first power source and said other electrode is floated;
- and
- in a fourth period, lower n bit of said digital signal respectively control n switches and said one electrode is connected to the first power source or said second power source and said other electrode is connected to said output line.
A semiconductor device which comprises a source signal line driver circuit, a gate signal line driver circuit and a pixel section, wherein the source signal line driver circuit comprises a D/A converter circuit which converts a 2n bit digital signal into an analog signal, said D/A converter circuit comprising:
- n switches, n capacitors and a coupling capacitor, where n is a natural number,
- wherein said n capacitors are connected to an output line in an upper bit writing period, and
- wherein said n capacitors are connected to said output line through said coupling capacitor in a lower bit writing period.
Dependencies are inferred from the claim text.