| 摘要 |
PURPOSE:To enable a driver circuit for PNPN switches for spacedivision channel switches of a telephone switchboard to operate at a high speed, by flowing a gate current from a PNPN switch directly to a gate-current absorbing driver circuit not through a transformer. CONSTITUTION:In a driver circuit for PNPN channel switches 40-43, constant- current circuits 50 and 51 are connected to a row-directional anode group of PNPN switches arranged in a matrix, 1st driver circuits 30 and 31 are to a column-directional gate group, and 2nd driver circuits 100 and 101 are direct to a row-directional cathode group; specially, gate-current absorbing driver circuits for PNPN switches are connected as 2nd driver circuits 100 and 101 before channel transformers 20 and 21. Consequently, influences of inductance and capacity of transformers can be reduced and high-speed operation is realized. |
