Patent ID: 8633744
Filing Date: 2014-01-21
Classification: G06F,H03K

Abstract:
1. A power reset circuit with zero standby current consumption, for generating a power reset signal according to a change of a supply voltage source, comprising: a power storage unit having a first critical voltage level, having an input end connected to the supply voltage source and an output end connected to the first reference node, being charged when a voltage level of the supply voltage source is higher than the first critical voltage level, and discharging when a voltage level of the supply voltage source is lower than the first critical voltage level; a first voltage detection unit connected between the first reference node and a second reference node to receive the supply voltage source, thereby causing a voltage of the second reference node to track a voltage of the first reference node when the supply voltage source is lower than a second critical voltage level, and thereby reducing a voltage of the second reference node to a reference voltage when the supply voltage source is higher than a second critical voltage level; a second voltage detection unit connected between the supply voltage source and the second reference node and connected to a third reference node, so as to enable a current path between the second reference node and the supply voltage source of the second voltage detection unit only when the third reference node has the reference voltage; a third voltage detection unit connected between the supply voltage source and the third reference node and connected to the second reference node, so as to enable a current path between the third reference node and the supply voltage source of the third voltage detection unit only when the second reference node has the reference voltage; a switching unit connected between the third reference node and a reference voltage end and connected to the second reference node so as to enable a current path between the reference voltage end and the third reference node of the switching unit only when the second reference node has the reference voltage, thereby reducing a voltage of the third reference node to the reference voltage; and a power reset unit having an input end connected to the third reference node and an output end for generating and outputting the power reset signal according to a voltage level of the third reference node.