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. 10, 2012
Filed:
Oct. 01, 2008
Lokesh Kumath, Bangalore, IN;
Giri N. K. Rangan, Bangalore, IN;
Lokesh Kumath, Bangalore, IN;
Giri N. K. Rangan, Bangalore, IN;
Intersil Americas Inc., Milpitas, CA (US);
Abstract
Circuits, methods, and apparatus that provide highly accurate DCPs. One example provides a DCP that includes a resistor string having taps that may be selected by a corresponding number of switches under the control of a digital word. To compensate for parasitic switch resistances and for variations in the values of the resistor sting caused by processing tolerances, a voltage-controlled resistor (VCR) is placed in parallel with the resistor string and switches. A control voltage generated using a control loop adjusts the parallel VCR such that the resistance seen across the DCP is the desired value. The control loop compares a reference resistor to loop components that are scaled to the resistor string, switches, and VCR. The reference resistor may be an external resistor or an internal resistor. If the resistor is internal, it may be trimmed, for example with lasers or fuses.