| US 7,515,080 B2 | ||
| A/D converter | ||
| Taiji Akizuki, Miyagi (Japan); Tomoaki Maeda, Hiroshima (Japan); and Hisashi Adachi, Osaka (Japan) | ||
| Assigned to Panasonic Corporation, Osaka (Japan) | ||
| Filed on Sep. 13, 2007, as Appl. No. 11/898,644. | ||
| Claims priority of application No. 2006-248364 (JP), filed on Sep. 13, 2006. | ||
| Prior Publication US 2008/0068246 A1, Mar. 20, 2008 | ||
| Int. Cl. H03M 3/00 (2006.01) | ||
| U.S. Cl. 341—143 [341/155] | 24 Claims |
| 1. An A/D converter comprising:
a single basic reference voltage;
a first switched capacitor block that has a first group of capacitors composed of a plurality of capacitors respectively connectable
to the basic reference voltage, and that charges and holds charges by connecting each of the first group of capacitors to
the basic reference voltage at a first timing, and discharges each of the charges held by the first group of capacitors at
a subsequent second timing;
a second switched capacitor block that has a second group of capacitors composed of a plurality of capacitors each connectable
to the first group of capacitors, and that, at the second timing, charges and holds each of the charges discharged by the
first group of capacitors respectively in the second group of capacitors, and, at the first timing, converts each of the charges
held by the second group of capacitors to a voltage and outputs the voltages; and
a quantizer that quantizes an analog input signal using the plurality of voltages output from the second switched capacitor
block as reference voltages for each level,
wherein a plurality of the reference voltages are generated from the single basic reference voltage, based on different amounts
of charges held in the plurality of capacitors.
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