Noise mechanism of TDMR readers at system level

In order to minimize the SNR drop at higher areal density, it has to push more on track density rather than linear density. One challenge from narrower track width is the inter-track interference (ITI). The TDMR readers are able to cancel ITI and are being implemented in HDD product. Due to the skew angle, one of TDMR readers has to read with crossing of two tracks. When the recording bits on two adjacent tracks are in opposite polarity, it may create multi-domains in read sensor and generates additional reader noises.