The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 20, 2009
Filed:
Feb. 20, 2008
Subhrajit Bhattacharya, White Plains, NY (US);
Subhrajit Bhattacharya, White Plains, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A power gated semiconductor integrated circuit comprises: (1) logic circuit to be power gated, said logic circuit having a virtual ground rail; (2) footer device disposed between said virtual ground rail and a ground rail for reducing power consumption of said logic circuit; and (3) virtual rail voltage clamp disposed electrically in parallel with said footer device for limiting the voltage at the virtual ground rail, the virtual rail voltage clamp comprising at least one NFET. A total of NNFETs are connected to the virtual ground rail of the integrated circuit for use as both virtual rail voltage clamps and footer devices. A quantity of NNFETs are scanned and perform the function of voltage clamps and the remaining (N−N) NFETs perform power gating. Manufacturing variability immunity and tuning of the variability immunity is achieved by adjusting the quantity Nbased upon testing of the manufactured integrated circuit.