Simulation of noise, signal-to-noise and bandwidth of TMR and CIP/CPP GMR heads

In magnetic data storage the noise and signal-to-noise ratio (SNR) of the read heads is becoming more and more of a limiting factor given the smaller readout devices needed to follow the ever higher areal densities. For higher data rates this problem is aggravated by the needed wider signal bandwidths. This study presents the magnetic simulation of noise, SNR, and bandwidth for the most common types of head: tunneling magnetoresistive heads, CIP-GMR heads, and CPP-GMR heads. Such simulations allow the comparison of these different types of head. The sensitivity factors of the SNR for the most important head parameters are determined as well. The SNR of the total read path is also determined, including the head-amplifier interconnect and the electronics.