| 摘要 |
PURPOSE: A cross over reducing circuit of an exchanger is provided to enhance switching speed by designing switching elements with MOSFET for fast switching. CONSTITUTION: A square wave input part comprises an oscillating power supply(Vs) generating the square wave of predetermined frequency, a photo diode(PD) which flickering status is controlled by the oscillating power supply(Vs), and a photo transistor(PT) synchronized with the photo diode to be turned on/off. A DC-DC converter(200) generates a ring signal having a predetermined voltage level supplied to a ring signal output. A first switching element(Q11) is synchronized with the photo transistor to be turned on/off. A second switching element(Q12) is synchronized with the on/off status of the first switching element(Q11) to be inverted in its on/off status. Third and fourth switching elements(Q13,Q14) are synchronized with the photo transistor to be turned on/off. Fifth and sixth switching elements(Q15,Q16) are synchronized with the on/off status of the photo diode to be inverted in their on/off status. The first to sixth switching elements are formed of MOSFET.
|
