| 摘要 |
PROBLEM TO BE SOLVED: To make high speed A/D conversion to have high linearity without deteriorating in resolution. SOLUTION: A lamp wave form producing circuit 3 is designed to produce a lamp wave form voltage VL which increases in constant inclination by synchronizing to a clock signal ADclk having a constant time cycle, and a voltage-time converting circuit 4 is designed to output signals PB1 at a time of producing the lamp wave form voltage VL and a time when the lamp wave form voltage VL corresponds to an input voltage Vin1. A pulse phase difference encoding circuit 8 has a ring delay line in inner portion, and is designed to encode pulse revolving numbers and a pulse position in each production time of the signals PB1. A differential data calculating circuit 9 is designed to output digital data TD which encodes a time interval between the signals PB1. A/D conversion code FD whose resolution is higher is obtained by passing the digital data TD through a digital filter 6. COPYRIGHT: (C)2006,JPO&NCIPI
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