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:
Jun. 11, 2013
Filed:
May. 07, 2010
Ken Kun-yung Chang, Los Altos, CA (US);
Kashinath Prabhu, Kamataka, IN;
Hae-chang Lee, Los Altos, CA (US);
Ken Kun-Yung Chang, Los Altos, CA (US);
Kashinath Prabhu, Kamataka, IN;
Hae-Chang Lee, Los Altos, CA (US);
Rambus Inc., Sunnyvale, CA (US);
Abstract
A driver supports differential and single-ended signaling modes. Complementary transistors with a common tail node are provided with complementary input signals in the differential mode. A current source coupled to the tail node maintains a relatively high tail impedance and a constant tail current in the differential mode. The tail node is set to a low impedance in single-ended modes to decouple the two transistors, allowing them to amplify uncorrelated input signals. The current source thaws multiple current levels in the single-ended mode to compensate for changes in tail current that result from changes in the relative values of the uncorrelated data in the single-ended modes. A termination block provides termination resistance in the differential mode, pull-up transistors in a single-ended mode that employs push-pull drivers, and is omitted in a single-ended mode that lacks driver-side termination.