| 摘要 |
PURPOSE:To reduce the number of elements to form a sine wave generating circuit, by adding the output signals of a ring counter to form a staircase waveform and then giving a correction only to the peak value of the said waveform through an operation of addition. CONSTITUTION:When a higher-order clock signal A is supplied to an 8-notation ring counter 4, H-level signals F1-F4 that shift successively and synchronously with the signal A are delivered from the output terminals Q of D-type flip-flops 41-44. An operational amplifier 731 carries out an addition for the resistance to which an H-level signal is supplied. The output voltage of the amplifier 731 is reduced at the area of the staircase waveform corresponding to the peak value of a sine wave by a resistance 725 that is connected between the output side of an NAND circuit 711 and a minus input terminal of the amplifier 731. Then a desired sine wave can be obtained by making an analog signal G to pass through an low- pass filter. |
