Patent ID: 7245245

Claim:
A digitizer without a current mismatch, comprising: a comparator, receiving two analog inputs and two digital outputs to adjust a slice level for slicing a plurality of analog data and generating a comparing signal; a charge pump circuit, receiving said comparing signal of said comparator and generating a first output signal at a first output end and a second output signal at a second output end, comprising: a first current source, providing current to said first output end or said second output end; a first switch, selectively switching said first current source according to said comparing signal of said comparator; a second current source, providing current to said first output end or said second output end; a second switch, selectively switching said second current source according to said comparing signal of said comparator; a current sink, providing current to said first output end or said second output end; and a third switch, selectively switching said current sink according to said comparing signal of said comparator; a capacitor, coupled between said first output end and said second output end of said charge pump circuit; and a low pass filter, receiving said first output signal and said second output signal of said charge pump circuit to generate said two digital outputs to said comparator.