JPS57171828A - Analog-to-digital converter - Google Patents

Abstract

PURPOSE:To prevent flickering in case of display, by converting digital signals of plural bits which have been A/D-converted, to series pulses of the corresponding number, counting them, and displaying a means value obtained by executing the conversion 10 times. CONSTITUTION:When the first command signal STC is inputted to an A/D converter 11, an analog input signal is A/D-converted, corresponding digital signals b1-bn are outputted, are inputted to a counter 12 by a conversion end signal EOC, simultaneously a gate 14 is opened, a clock pulse CLK is supplied to a down-counter 12, and when a borrow signal BR rises, a clock pulse Ps is supplied to counters 191-194 through a gate 16. When the counter 12 executes down-counting and becomes ''0'', the borrow signal is gone and the gate 16 is closed. When said converting and counting operations are executed 10 times, contents of a counter 19 are transferred to a latch 20 by a signal TRF, and subsequently, as for a numerical value of each digit, upper 3 digits are displayed on a display device 24 by a signal except the lowest digit signal T4 of digit signals T1-T4.