US Patent 7692998 Circuit of detecting power-up and power-down

A power-up/power-down detecting circuit may include a power detecting circuit, a selecting circuit, and a determining circuit. The power detecting circuit may generate a plurality of detection signals based on a plurality of sensing signals corresponding to currents flowing through a plurality of function blocks. The selecting circuit may generate a plurality of selection signals. The determining circuit may generate a power-up completion signal and a power-down completion signal. A semiconductor device having the power-up/power-down detecting circuit may determine in real time the power-up time and the power-down time.