| 摘要 |
PURPOSE:To reduce the electric power consumption by making the voltage of an operation switch circuit lower than that of a reference circuit when sampling is not performed in a switch detecting circuit. CONSTITUTION:A series circuit consisting of a resistance 6 and a transistor (TR) Q5 is connected in parallel to a series circuit consisting of resistances R1-R6 and operation switches SW1-SW6, and the TRQ5 is controlled by a terminal (d) so that this TR is made conductive in a period (when no voltage is applied to terminals (a)-(c)) other than the sampling period. Resistances 6R and 8R has a relation 6R<8R; and when the TRQ5 is turned on, an operation switch circuit voltage (f) is made lower than a reference circuit voltage (g) independently of turning-on/off of operation switches SW1-SW6, and the output is not generated from a comparator, and a TRQ1 is turned off, and a current is not flowed, and thus, the power consumption is minimized. |
