Patent Number: 6,298,459

Title: Analog to digital converter with encoder circuit and testing method therefor

Abstract: A high speed A/D converter includes a series of encoder sections for converting a thermometer code to a gray code and an error signal production section for detecting a babble error in the gray code and generating an error signal indicating such a babble error. An error correction section corrects babble errors in the gray code in response to the error signal. The corrected gray code is then converted to a binary code with a gray code to binary code converter. When the high speed A/D converter is incorporated in a semiconductor device, the A/D converter may be tested using a sampling clock having a phase which varies successively with respect to the input analog signal to sample the analog signal, and then evaluating the corresponding generated digital signal.

Inventors: Tsukamoto; Sanroku (Kasugai, JP)

Assignee: Fujitsu Limited

International Classification: H03M 13/00 (20060101); H03M 1/06 (20060101); H03M 13/47 (20060101); H03M 1/10 (20060101); H03M 1/08 (20060101); H03M 1/36 (20060101); G06F 011/00 ()

Expiration Date: 10/02/2018