Patent ID: 7079065

Claim:
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.