US Patent 7724581 Discharge order control circuit and memory device

A discharge order control circuit includes a pool circuit a delay circuit and a discharge unit to control a discharge order of internal power supplies. The pool circuit stores electric charges provided from a potential of an external power supply. The delay circuit operates on the electric charges stored in the pool circuit and delays a discharge signal generated when potential of the external power supply is lowered to a predetermined potential level. The delay circuit includes an inverter array having a plurality of stages each containing an inverter. The plurality of stages include a final stage that outputs the delayed discharge signal. Only the inverter of the final stage generates an RC delay.