Patent ID: 7714643

Claim:
A method of tuning an analog filter of a circuit, the method comprising: providing a configurable signal path, wherein at least a portion of the configurable signal path is selectable between at least a first signal path or a second signal path, wherein the second signal path includes one or more stages of the analog filter, wherein the first signal path bypasses the one or more stages of the analog filter; providing a test signal generator having an output to an input of the configurable signal path; providing an analog-to-digital converter having an input operatively coupled to an output of the configurable signal path; providing a filter tuning engine having an input operatively coupled to an output of the analog-to-digital filter, wherein the filter tuning engine implements a time-invariant infinite impulse response (IIR) filter; generating a test signal as an output of the test signal generator and providing the test signal to an input of the configurable signal path; bypassing the one or more stages of the analog filter by selecting the first signal path for the configurable signal path; determining a first response to a test signal of the first signal path to the test signal by capturing an output of the configurable signal path with the first signal path selected, wherein capturing is performed by the analog-to-digital converter and the filter tuning engine; digitally filtering the first response with the time-invariant infinite impulse response (IIR) filter to generate a second response; enabling the one or more stages of the analog filter by selecting the second signal path for the configurable signal path; determining a third response of the second signal path to the test signal by capturing the output of the configurable signal path with the second signal path selected, wherein capturing is performed by the analog-to-digital converter and the filter tuning engine; comparing the third response to the second response, wherein comparing is performed by the filter tuning engine; and selecting one or more filter parameters for adjustment of the one or more stages of the analog filter based at least partly on the comparison, wherein selecting is performed by the filter tuning engine.