Patent ID: 6590428
Filing Date: 2003-07-08
Classification: G11C,H03K

Abstract:
A method of determining whether a potential on a node remains constant, comprising:providing a differential comparator connected between upper and lower supply lines and having a first input connected to said node, a second input connected to a precharge potential and an output, wherein said first input becomes active at a lower applied potential than the second input, the comparator having a first enabled state in which said output represents a difference between the first and second input potentials and a second disabled state, wherein the comparator has no path for current flow between said supply lines in said enabled and disabled states; connecting the node to said precharge potential whereby said node is precharged, while maintaining the disabled state; disconnecting the node from said precharge potential; and after a time delay, causing said comparator to switch to the enabled state, whereby said output indicates whether the node potential remains constant.