| 摘要 |
PURPOSE:To prevent the malfunction of the input circuit for the watch-use integrated circuit by connecting the N-type MOSTr which conducts simultaneously with conduction of P-type MOS transistor Tr to the input and common terminals. CONSTITUTION:The drain of conducting P-type MOSTr1 is connected to the drain of N-type MOSTr2 of the resistance element, and the sources of Tr1 and 2 are connected to input terminal 11 and the earth of the common terminal. N-type MOSTr5 is connected to both the input terminal and the common terminal. In case the 2nd control signal applied to the gate of Tr2 changes from 1 to 0 and at the same time the 4th control signal applied to the gate of Tr5 changes from 0 to 1 with input terminal 11 opened, the load resistance reduces and the charge of parasitic capacity C1 also reduces suddenly since Tr5 is connected in parallel to the serial circuit of Tr1 and Tr2. As a result, the maximum potential of connection point 10 is lowered down, and the reading malfunction of the input circuit caused by parasitic capacity C1 and C2 when terminal 11 is open can be prevented. |
