Digital magnetic read channel and method

摘要

Disclosed is a system and method for generating a data sequence from a two frequency coherent phase signal. The system comprises an integrated magnetic read channel that includes a magnetic reader circuit configured to generate an analog two frequency coherent phase (F2F) signal from a magnetic strip, the analog F2F signal having a number of alternating positive and negative peaks having a respective positive and negative transitions therebetween. The output of the magnetic reader circuit is applied to an analog-to-digital converter configured to convert the analog F2F signal into a digital F2F signal. Thereafter, the digital F2F signal is applied to a peak detector configured to identify the alternating negative and positive peaks. The magnetic read channel also includes a transition calculator configured to determine a transition time between each of the consecutively positioned alternating positive and negative peaks, and a frequency locked loop configured to determine a transition type for each of the transition times. Finally, the output of the frequency locked loop is applied to a data separator configured to determine a data value from the transition types.