| 摘要 |
PURPOSE:To reduce power consumption by detecting one specific state of two digital signals and its inverted state and controlling the output period of the detected signal by one digital signal and a gate signal having a fixed phase. CONSTITUTION:The 1st detecting circuit 22 detects a specific state, e.g. A, B= ''1'', ''0'', out of the combination of input signals A, B and the 2nd detecting circuit 23 detects its inverted state A, B=''0'', ''1''. The gate signal is a signal enabled to gate the phase comparing edge (rising edge) of the input signal B and having a fixed phase difference. When the 1st power supply 24 is the constant voltage source of an output voltage VH and the 2nd power supply 25 is the constant voltage source of an output voltage VL, only a switching circuit 26 is conducted and the voltage VH is outputted during the period of an output from the circuit 22, and only a switching circuit 27 is conducted and the voltage VL is outputted during the period of an output from the ciruit 23. In said constitution, both circuits 26, 27 are not conducted simultaneously and the circuit on the output stage consumes its electric power only for the period of a phase difference, so that the power consumption can be reduced. |
