JPS6439114A - Pulse producing circuit - Google Patents

Abstract

PURPOSE:To produce pulses without applying bias voltage to a differential waveform and to avoid deterioration of the level margin, by adding a monostable multivibration circuit and two D .FFs to an absolute value differential pulse producing circuit. CONSTITUTION:The comparison 3 is carried out between differential waveforms C and D so that a waveform F is obtained. This waveform F is supplied to a monostable multivibration circuit 4. Thus the waveforms G and H are obtained with the positive and negative polarity outputs respectively. The waveform H is divided into two parts by a 1st D.FF 5 and a waveform I is obtained. The waveform I is supplied to a data terminal (d) of a 2nd D.FF 6 and the waveform G is supplied to a clock terminal (ck). The state of the terminal (d) is checked are the rise of the waveform G so that a waveform like a waveform J where the pulse rises only at the peak point of a reproduction signal is obtained at the output Q of the FF 6. Then the value of the pulse width TW is set smaller than the time Td, i.e., the positive or negative polarity of a differential, waveform and larger than the narrow pulse width. Thus it is possible to prevent the level margin deterioration due to the bias voltage of a pulse signal J.