ANALOG-TO-DIGITAL CONVERTER CONTROLLING METHOD

摘要

PROBLEM TO BE SOLVED: To improve the speed of an A/D converter by reducing a conversion time in A/D conversion of a successively comparing system. SOLUTION: By selecting one of plural kinds of timing signals generated based on the two signals of different frequency dividing ratios, it becomes possible to change the period of a control signal TZ1 by each comparing section T1 to T4. Thus, according to a frequency-changed control signal, a reference voltage VRF and an inputted voltage VIN are compared with each other. Thus, a difference between the reference voltage of last time and that of this time is increased and the period of the control signal is reduced excepting for a comparing section T2 requiring time until the stabilizing of the reference voltage.