| 摘要 |
PURPOSE:To improve noise immunity by rectifying the output signal of a specific signal conversion circuit and a bridge circuit comprising N-channel and P- channel transistors(TRs) via a pulse transformer. CONSTITUTION:An AND circuit 5 receives signals S1, S2 and outputs a signal S4, an AND circuit 6 outputs a signal S5 from a signal S3 resulting from the signal S2 inverted by an inverter 4 and the signal S1, and the signals S4, S5 have a different phase by 180 deg.. A group comprising an N-channel TR 10 and a P-channel TR 13 and a group comprising an N-channel TR 12 and a P-channel TR 11 switch alternately the signals. Through the operation above, an output signal waveform at the secondary coil of a transformer 9 is a signal S6 being the synthesis of the inverse of the signal S5 and the signal S4. When the signal S6 is rectified by a rectifier circuit 18, the signal S7 of the same waveform of the input signal S1 is decoded and outputted. The pulse current of a primary coil is inverted alternately in the transformer 9 being a pulse transformer to suppress the local magnetization of the transformer, thereby improving noise immunity. |
