Patent ID: 7589795
Filing Date: 2009-09-15
Classification: H03M,H04N

Abstract:
1. An automatic clamping analog-to-digital converter (A/D converter), comprising: an A/D converter, receiving an analog signal from a node, converting the analog signal into a digital signal according to a DC offset level, and outputting the digital signal; a comparator, outputting a compare signal according to a comparison result between the digital signal and an offset value; a bidirectional counter, outputting a count, and increasing or decreasing the count according to the compare signal; a digital-to-analog converter (D/A converter), converting the count into the DC offset level, providing the DC offset level to the A/D converter; and a switch, coupled between the node and a fixed voltage level, being turned on or off according to a clamping signal; wherein at least one of the comparator and the bidirectional counter only works within a clamping interval of the analog signal.