| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that it is difficult in an AD converter to realize voltage reduction without being accompanied with circuit area expansion or property deterioration. SOLUTION: A multi-stage pipelined AD converter 20 has (n) stages of conversion units, such as a first conversion unit 22, a second conversion unit 24, an (n-1)th conversion unit 26, and an n-th conversion unit 28, which successively convert an analog signal into a digital signal each by several bits starting from the most significant bit. Each of the converted digital signals of several bits is combined in a digital output circuit 30. A first voltage source VDD1 supplies a higher voltage than a second voltage source VDD2. The first voltage source VDD1 supplies a high voltage to the first stage of the first conversion unit 22, while the second voltage source VDD2 supplies a low voltage to the second and subsequent stages of the second conversion unit 24 to the n-th conversion unit 28 which require a lower analog accuracy. COPYRIGHT: (C)2007,JPO&INPIT
|
