| 摘要 |
PURPOSE:To prevent the deterioration of S/N of an A/D converter, by providing plural integrators on the pre-stage of a comparator which compares the output of the integrators with a reference value and allowing each integrator to operate at clocks of a frequency which is 1/n of the frequency of the operating clock of the comparator. CONSTITUTION:Two integrators 2a and 2b are provided on a comparator 3 and the input of each integrator 2a and 2b is sampled at clocks whose frequency is 1/2 of a desired frequency whose the phase is shifted by a half period. Since one integrator 2b can start its integrating operation while the output of the other integrator 2a is compared at the comparator 3, the one integrator can be operated with the frequency which is 1/2 of the sampling frequency when attention is paid to the one integrator and the degree of time to spare to the settling time becomes larger. Therefore, deterioration of S/N due to insufficient speeds of the integrators can be prevented.
|
