SIGNAL VOLTAGE DETECTING CIRCUIT

摘要

PURPOSE:To shorten the working time by reflecting the potential difference between the 1st and 2nd nodes to the potential difference to be detected and charging or discharging the 1st and 2nd capacity charges via the 2nd MOS transistor. CONSTITUTION:The electric charge stored in the capacity of a lower potential level between the capacity C1 produced between an identification output node N1 and the earth and the capacity C2 produced between an identification output node N2 and the earth is discharged positively via MOS transistors (TR)Q1 and Q3 or Q2 and Q3 respectively. Thus the potential difference between both nodes N1 and N2 is increased. Here said discharge of the electric charge is carried out while both MOSTRs Q8 and Q9 are kept off. Therefore the electric charges stored in both capacities C1 and C2 formed between the nodes N1 and N2 and the earth respectively are never discharged through the TRs Q8 or Q9. This can decrease the working time during which the potential difference between both nodes N1 and N2 is increased and delivered as an identification output signal.