| 摘要 |
PROBLEM TO BE SOLVED: To compare a value of an analog signal with a predetermined value by a comparatively simple circuit and in a short period of time. SOLUTION: An analog signal comparator includes: an oscillator 21A which produces a first pulse signal; a VCO 22 which inputs an analog signal, converts the analog input signal to a second pulse signal, and outputs it; a first shift resistor 241 which inputs the first pulse signal from the oscillator 21; a second shift resistor 242 which inputs the second pulse signal from the VCO 22; and the number-of-pulses comparing circuit which detects the values of all bits or some bits of the first and second shift resistors 241, 242, and based on those detected values, compares the number of first pulse signals produced by the oscillator 21A with the number of second pulse signals produced by VCO 22. COPYRIGHT: (C)2009,JPO&INPIT |
