Patent ID: 7837110

Claim:
A magnetic card stripe reader circuit comprising: an analog input terminal, an analog signal having a plurality of peaks being present on the analog input terminal; an analog front end sensor circuit that detects the analog signal on the analog input terminal and outputs a corresponding stream of digital sample values; and a digital peak detector circuit that receives the stream of digital sample values, the digital peak detector circuit: defines a positive minimum threshold and a negative minimum threshold; analyzes a first portion of the stream over a first time period and above the positive minimum threshold such that a plurality of positive peaks are iteratively identified within the first portion of the stream; analyzes a second portion of the stream over a second time period and below the negative minimum threshold such that a plurality of negative peaks are iteratively identified within the second portion of the stream; identifies a maximum positive peak value within the plurality of positive peaks and a maximum negative peak value within the plurality of negative peaks; and outputs a plurality of peak values including a first peak related to the maximum positive peak and a second peak related to the maximum negative peak, each peak value, within the plurality of peak values, being indicative of a corresponding one of the peaks in the analog signal, wherein the digital peak detector circuit is not part of a general purpose processor.