Patent ID: 6617921
Filing Date: 2003-09-09
Classification: H03F

Abstract:
A high gain differential input and output stage circuit for a comparator device comprising:a first common mode setting portion coupled to a first differential output; and a second common mode setting portion coupled to a second differential output; wherein the first and second common mode setting portions have a first state in which the first and second common mode setting portions are coupled to the respective differential outputs for setting the common mode bias output voltage of the stage during a common mode condition and a second state in which the first and second common mode setting portions allow the respective differential outputs to swing rail to rail during a differential mode condition; the first common mode setting portion comprising a first diode coupled transistor selectively coupleable to the first differential output and the second common mode setting portion comprising a second diode coupled transistor selectively coupleable to a second differential output; the first common mode setting portion further comprising a first switch provided for selectively coupling the first differential output to the second diode coupled transistor and the second common mode setting portion further comprising a second switch provided for selectively coupling the second differential output to the second diode coupled transistor, the first switch being a transistor disposed between a drain and a gate of the first diode coupled transistor and the second switch being a transistor disposed between a drain and a gate of the second diode coupled transistor.