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:
May. 30, 2006
Filed:
Jul. 02, 2004
Tawen Mei, Mountain View, CA (US);
Chunping Song, Santa Clara, CA (US);
Tawen Mei, Mountain View, CA (US);
Chunping Song, Santa Clara, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A method and circuit for compensating offset errors caused by propagation delays in hysteretic control loops. An overshoot voltage V, caused mainly by an inductor current overshoot, is tracked and held when a switch is to be turned off, and again when the switch actually turns off. A timing logic circuit provides control signals to a sample and hold circuit based on switch signals SW and OUT. A difference between the two sampled voltages is applied to a reference voltage in a hysteretic voltage regulator. By monitoring the overshoot voltage and automatically compensating for it in real-time, a knowledge of a value of the propagation delay is not needed. Thus, significantly improved accuracy may be achieved despite variable factors such as propagation delay variations, temperature changes, component tolerances, and the like.