Patent ID: 7026971

Claim:
A monotonic digital-to-analog converter for converting a digital input signal into an analog output signal, the converter comprising: an input node for receiving the digital input signal having at least M+L bits, an output node for delivering the analog output signal corresponding to the received digital input signal, a coarse conversion block comprising current sources and first switching means for converting M more significant bits of the digital input signal into a coarse block output current, a fine conversion block comprising a current divider and second switching means for converting L less significant bits of the digital input signal into a corresponding current value, the fine conversion block having means for receiving current from a first of N unselected current sources of the coarse conversion block, the monotonic digital-to-analog converter furthermore comprising: a first cascode means (OA 1 +MC 1 ) for active cascading the coarse block output current, and a second cascode means (OA 2 ) for active cascading the current from the first unselected current source.