| 摘要 |
<p>PROBLEM TO BE SOLVED: To eliminate insufficient charging of a D-type flip flop, even when the speed of the frequency is significantly increased by securing a longer effective charging period, including the charging period by charging the flip flop by driving an independent charging system in a stage before shifting to the charging period, immediately after different states of potentials (low potential- and high potential-side power supply potentials) are decided with respect to the two input terminals of an RS latch in an evaluating period. SOLUTION: A set input terminal S of an RS latch 2 is charged through a Pch transistor TP1 and also via a transistor TP3 and a Pch transistor TP50 by setting the transistors TP50 and TP51 in conducting states and, in addition, an NCh transistor TN300 in nonconducting state, by outputting a VSS potential from a two-input EXNOR circuit XNOR, at the same time as from the time when the set input terminal S of the latch 2 becomes a VDD potential and the reset input terminal R of the latch 2 becomes a VDD potential in an evaluating period, not after starting a charging period, but starting already in the evaluating period. Even when the evaluating period starts from a state where the set input terminal S is in a VDD-potential state and the reset input terminal R of the latch 2 is in a VSS-potential state, the charging is also started similarly not after the charging period starts, but in the evaluating period.</p> |
