| 摘要 |
PURPOSE:To reduce and stabilize the current of an input circuit, by inserting a resistance between an input terminal and a power supply terminal in a detecting circuit which detects the state of the input terminal synchronously with a control signal. CONSTITUTION:The state of an input terminal 2 is detected by a detecting circuit consisting of FET7-9 and synchronously with a control signal 3. The output of an inverter 5 which is supplied to the subsequent circuits is set at a low level while a signal of a high level is applied to the terminal 2. An FET9 is turned on only when the signal 3 is kept at a high level. The value of a resistance 10 is set sufficiently larger than the ON-resistance of the FET9. Thus the current of the FET9 depends on the value of the resistance 10 and can be set at a small and stable level. When the signal 3 is set at a high level in case no input is applied to the terminal 2, the output of the inverter 5 is set at a high level. This state is kept thereafter. Thus the current consumption becomes zero for the input circuit which is shown in the diagram. |
