Digital-to-analog converter and the driving method thereof
AssigneeHannstar Display Corp.
InventorsChun-Fu Wang, Feng-Ting Pai
Life of this patent
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Abstract
The present invention describes a circuit and driving method for a digital-to-analog converter to convert an (m+n) bits digital signal to an analog signal. First, the (m+n) bits digital signal is separated into a first set of m first bits and a second set of n second bits. Then, according to the first set of m first bits, a reference voltage range is determined from a plurality of reference voltages. Finally, according to the second set of n second bits, a voltage is determined from the reference voltage range.
Claims17
A digital-to-analog converter, adapted to converting a digital signal with m+n bits to a voltage, the digital-to-analog converter comprising:
- a plurality of bus lines, supplying a plurality of reference voltages;
- a first circuit, having m first bits of the digital signal, the first circuit electrically connecting to the bus lines to receive the reference voltages and choosing a reference voltage range from the reference voltages;
- and
- a second circuit, having n second bits of the digital signal, the second circuit having at least an input, wherein the input is connected to the first circuit to receive the reference voltage range and choose the voltage to output to a buffer, and the second circuit further comprising:
- a plurality of voltage-dividing circuits, electrically connected in series, wherein each of the voltage-dividing circuits comprises a first switch and a first resistor and the first switch and the first resistor are connected in parallel;
- and
- a second resistor, electrically series-wound to the voltage-dividing circuits;
- wherein the voltage-dividing circuits correspond one-to-one to the second bits and the complement, and the first switch of each voltage-dividing circuit is controlled by a second bit or a complement of the second bit corresponding to the first switch.
A method for digital analog conversion, adapted to converting a digital signal with (m+n) bits to a voltage, the method for digital analog conversion comprising:
- separating the digital signal with (m+n) bits into a first set of m first bits and a second set of n second bits;
- determining a reference voltage range from a plurality of reference voltages according to the first set of m first bits;
- and
- determining the voltage from the reference voltage range according to the second set of n second bits, wherein step of determining the voltage is perform by a circuit comprising:
- a plurality of voltage-dividing circuits, electrically connected in series, wherein each of the voltage-dividing circuit comprises a first switch and a first resistor and the first switch and the first resistor are connected in parallel;
- and a second resistor, electrically series-wound to the voltage-dividing circuits;
- wherein the voltage-dividing circuit corresponding one-to-one to the second bits and the complement, and the first switch of each voltage-dividing circuit is controlled by a second bit or a complement of the second bit corresponding to the first switch.
Dependencies are inferred from the claim text.