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. 16, 2007
Filed:
Mar. 16, 2004
David James Megaw, Tucson, AZ (US);
Paul Ranucci, Tucson, AZ (US);
David James Megaw, Tucson, AZ (US);
Paul Ranucci, Tucson, AZ (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
An apparatus and method for producing an output reference voltage is provided. A voltage divider is configured to provide the output reference voltage from a bandgap reference voltage. The bandgap reference voltage is applied across a biased portion of the voltage divider. Additionally, a second-order temperature coefficient (TC) of the impedance of a controllable portion of the voltage divider is adjusted in response to a second-order trim signal. The first and zeroth order TCs of the controllable portion of the voltage divider are substantially independent of the second-order trim signal. In one embodiment, the controllable portion includes a resistor digital-to-analog converter (DAC) that is responsive to the second-order trim signal. The resistor DAC includes at least two different types of resistors. The second-order TCs of the two different types of resistors are substantially different.