Wei T Lim

US Patent:

8046186, Oct 25, 2011

Filed:

Dec 18, 2008

Appl. No.:

12/337830

Inventors:

Wei Tjan Lim - Fort Collins CO, US
Ricky Bitting - Fort Collins CO, US
David Noeldner - Fort Collins CO, US
Michael Buehner - Fort Collins CO, US

Assignee:

LSI Corporation - Milpitas CA

International Classification:

G06F 19/00

US Classification:

702107

Abstract:

Described embodiments provide a method for calibrating a continuous-time filter having at least one adjustable parameter. A square-wave signal is filtered by a continuous-time filter having a cutoff frequency less than fs. The filtered signal is quantized at the rate fs. An N-point Fourier transform is performed of the quantized signal into N real output values and N imaginary output values. At least one of the real output values are accumulated to form a real output signal and at least one of the imaginary output values are accumulated to form an imaginary output signal. The real and imaginary output signals are summed to form an output signal, which is then squared. The squared output signal is compared to a comparison value. At least one parameter of the continuous-time filter is adjusted based upon the comparison. The steps are repeated until the squared output signal is approximately the comparison value.

US Patent:

20130314110, Nov 28, 2013

Filed:

May 28, 2012

Appl. No.:

13/481909

Inventors:

Bruce Walter McNeill - Yokohama-shi, JP
Peter John Windler - Fort Collins CO, US
Wei T. Lim - Fort Collins CO, US

Assignee:

LSI CORPORATION - Milpitas CA

International Classification:

G01R 27/14

US Classification:

324705

Abstract:

A measurement circuit is provided for measuring the resistance of a variable resistance element biased with an external voltage supply. The measurement circuit includes an analog-to-digital converter (ADC) and a reference generator connected with the ADC. The ADC is operative to receive a reference voltage and a first voltage developed across the variable resistance element, and to generate a digital output signal indicative of a relationship between the first voltage and the reference voltage. The reference generator is operative to generate the reference voltage as a function of the external voltage supply.