| US 7,477,177 B2 | ||
| A-D converter, A-D convert method, and A-D convert program | ||
| Yasuhide Kuramochi, Tokyo (Japan); and Akira Matsuzawa, Tokyo (Japan) | ||
| Assigned to Advantest Corporation, Tokyo (Japan); and Tokyo Institute of Technology, Tokyo (Japan) | ||
| Filed on Sep. 13, 2006, as Appl. No. 11/520,436. | ||
| Prior Publication US 2008/0143574 A1, Jun. 19, 2008 | ||
| Int. Cl. H03M 1/12 (2006.01) | ||
| U.S. Cl. 341—156 [341/155; 341/158] | 12 Claims |
| 1. An A-D converter that outputs a digital output signal obtained by digitalizing an analog input signal, comprising:
a plurality of comparators that each compare the analog input signal and an analog threshold value according to designated
digital threshold data;
a high-order field determining section that narrows down a data value corresponding to a high-order field of a predetermined
bit number in the digital output signal based on a plurality of comparison results obtained by supplying threshold data different
from one another to the plurality of comparators;
a low-order field computing section that computes a plurality of candidate values for a data value corresponding to a low-order
field of a predetermined bit number located at a side lower than the high-order field by means of the plurality of comparators;
and
a low-order field determining section that determines a data value corresponding to the low-order field based on the plurality
of candidate values.
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