Patent ID: 6052076
Filing Date: 2000-04-18
Classification: H03M

Abstract:
A digital-to-analog converter (DAC) for converting a digital input word to an analog output signal, the digital input word having a plurality of bit positions for establishing a resolution for the DAC, the plurality of bit positions defining first and second groups of bits, the DAC comprising:circuit means responsive to the first group of bits for producing a pair of analog control signals, one of the pair defining a common-mode magnitude while the other of the pair defines a sum of the common-mode magnitude and a differential magnitude, the common-mode magnitude being a function of the value of the first set of bits and the differential magnitude being a function of the number of bit positions in the first group of bits;a clock for generating a clocking signal;a state machine having an input for receiving the clocking signal, an input for receiving the second groups of bits, and an output for providing a time-varying control signal;switching circuit means having a pair of inputs for receiving the pair of analog control signals, and an input for receiving the time-varying control signal, and an output for providing a pulse-percentage and amplitude modulated signal; andaveraging circuit means responsive to the pulse-percentage and amplitude modulated signal for producing the analog output signal.