A good Magnetic Card Reader requires reliable and accurate performance across a variety of different environments and card swipe speeds; regardless of the physical condition of the card. There are three essential elements of a magnetic card that must be implemented in order to ensure this performance: (1) automatic gain control (AGC) to automatically adjust the amplitude of the input waveform to maximize dynamic range; (2) accurate peak detection and raw data decoding; and (3) preventing noise in the system from causing erroneous readings. Using a PGA and an ADC, the input waveform can be measured and scaled to maximize the dynamic range of the system; which will allow a wide range of input waveforms to be detected. This article will also show what techniques can be used to accurately detect peaks in the input waveform to read the essential information from the magnetic card. Lastly, creative techniques on how to eliminate false readings due to noise in the system will be discussed. To read more, click the download link below or visit: EE Times.
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