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:
Apr. 17, 2007
Filed:
Sep. 16, 2005
Paul John Morrow, Limerick, IE;
Maria Del Mar Chamarro Marti, Valencia, ES;
Colin G. Lyden, Cork, IE;
Mike Dominic Keane, Limerick, IE;
Robert W. Adams, Acton, MA (US);
Richard Thomas O'brien, Limerick, IE;
Paschal Thomas Minogue, Limerick, IE;
Hans Johan Olaf Mansson, Limerick, IE;
Atsushi Matamura, Tokyo, JP;
Andrew Abo, Can Jose, CA (US);
Paul John Morrow, Limerick, IE;
Maria del Mar Chamarro Marti, Valencia, ES;
Colin G. Lyden, Cork, IE;
Mike Dominic Keane, Limerick, IE;
Robert W. Adams, Acton, MA (US);
Richard Thomas O'Brien, Limerick, IE;
Paschal Thomas Minogue, Limerick, IE;
Hans Johan Olaf Mansson, Limerick, IE;
Atsushi Matamura, Tokyo, JP;
Andrew Abo, Can Jose, CA (US);
Analog Devices, Inc., Norwood, MA (US);
Abstract
A sigma-delta digital-to-analog converter comprises a current digital-to-analog converter (IDAC) stage which generates a current depending on an input digital signal. An output current-to-voltage converter converts the generated signal to a voltage on a continuous-time basis. The amplifier used in the output current-to-voltage converter is chopper-stabilized. The converter can be single bit or multi-bit. The IDAC stage can be implemented with a pair of branches, a first branch comprising a first biasing current source and a second branch comprising a second biasing current source. The biasing current sources can be chopper-stabilized by connecting the bias current sources to the output current-to-voltage converter by a set of switches. The switches connect the biasing current sources to the output current-to-voltage converter in a first configuration and a second, reversed, configuration. This modulates flicker noise contributed by the bias current sources to the chopping frequency. from where it can be removed by filtering downstream of the current-to-voltage converter.