Patent ID: 7479807
Filing Date: 2009-01-20
Classification: H03K

Abstract:
1. A device for maintaining voltage on a node of first electrical circuit comprising: a leakage current generator for generating a predefined analog current passing through a first transistor of a current mirror circuit, a current mirror circuit comprising a first and second transistor, the current mirror circuit coupled to the leakage current generator so that the predefined analog current passes through the first transistor and wherein a second current passes through the second transistor, the second analog current being proportional to the predefined analog current; and a non-reconfigurable keeper circuit operatively coupled between and to the second transistor of the current mirror circuit and the node of the first electrical circuit, thereby isolating the current mirror from the node of the first electrical circuit, the keeper circuit comprising a first set of P-type transistors connected in series from drain to source and a second set of N-type transistors connected in series from drain to source to the P-type transistors, thereby exhibiting a node of the keeper circuit between the P-type and N-type transistors, the keeper circuit node being electrically connected to the node of the first electrical circuit, the keeper circuit node further connected through an inverter to all the gates of the N-type and P-type transistors in the keeper circuit.