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. 01, 1999
Filed:
Aug. 26, 1997
Bhupendra K Ahuja, Fremont, CA (US);
C-Cube Microsystems, Milpitas, CA (US);
Abstract
An improved current steering cell for a DAC which eliminates the need for an inverter reduces the noise at the common mode. The cell includes a first and a second current steering MOS transistor of a first polarity type, each having a gate and a pair of current passing terminals. The cell has an input terminal for receiving digital input signals coupled to the gate of the first of the pair of current steering transistors, and a common mode node for receiving an input current coupled to the same one of the pair of current passing terminals of each current steering MOS transistor. The current output terminal of the cell is coupled to the other of the pair of current passing terminals of the first of the current steering MOS transistors. Finally, the cell includes a third MOS transistor of the opposite polarity type to the current steering MOS transistors, having a gate and a pair of current passing terminals for passing a current through the transistor, the gate of the third MOS transistor being coupled to the gate of the first MOS current steering transistor, and the current passing terminals of the third MOS transistor being coupled between the gate of the second MOS current steering transistor and one of the pair of current passing terminals of the second MOS current steering transistor.