Patent ID: 7365670
Filing Date: 2008-04-29
Classification: H03M

Abstract:
1. A digital-to-analog converter for converting a digital input signal to an analog output voltage, comprising: a first resistor string for generating a series of voltages spanning an upper range, a lower range, and a midrange disposed between the upper range and the lower range, the voltages being equally spaced in the midrange and unequally spaced in the upper range and the lower range; a lower selector for selecting one of the voltages in the lower range as the analog output voltage when the digital input signal has a value equal to or less than a first boundary value; an upper selector for selecting one of the voltages in the upper range as the analog output voltage when the digital input signal has a value equal to or greater than a second boundary value; a pair of midrange selectors for selecting a mutually adjacent pair of voltages in the midrange when the digital input signal has a value between the first and second boundary values; a midrange voltage generator for generating a further series of voltages between the pair of voltages selected by the pair of midrange selectors; and an output selector for selecting one of the voltages in the further series of voltages as the analog output voltage when the digital input signal has a value strictly between the first and second boundary values.