| 摘要 |
PURPOSE:To suppress ringing by absorbing a nose generated at the time of driving at a high speed a large capacity load connected to a semiconductor integrated circuit, by a capacitor provided between power source lines in the integrated circuit. CONSTITUTION:Output buffers f0-f7 which become loads are connected to a semiconductor integrated circuit. Also, between a power source line Lv and Le, a MOSFET Mr and a capacitor Cg are connected. An FET Mr is an N channel type and turned on by connecting the gate to the power source Lv, and operates as a resistance of a time constant circuit. The capacitor Cg bypasses a high frequency component through a power source Vcc, and stabilizes a level of the line Le. An input signal of output buffers f0-f7 rises to an H level from an L level, a MOSFET Mb (Mb0-Mb7) is turned on, and when charge stored in loads Cl0-Cl7 is discharged, its charge is stored temporarily in the capacitor Cg, and thereafter, discharged gradually through inductances lg, ls. In such a way, the generation of a current noise is prevented, and ringing is suppressed.
|
