TLS2158

The TLS2154, TLS2156, and TLS2158 are BiCMOS, monolithic preamplifiers designed for two-terminal thin-film or metal-in-gap (MIG) recording heads. The preamplifiers incorporate data-protection circuitry for all channels and feature low-noise read paths and write-current controls. When deactivated, the preamplifiers enter an idle mode that reduces power dissipation to 0.5 mW, typically. The write-current generator is disabled during power sequencing to provide power-supply fault protection.

During write and idle modes, the differential read-data (RDX and RDY) lines are placed in a high-impedance state to improve system write-to-read and idle-to-read recovery times. The servo-write feature allows increased throughput at the servo-write stage. TLS2156 and TLS2158 have multiple-head-select servo-write functions. Isolated damping resistors effectively switch out the resistance during read operations.

The 24-pin TLS2154 and 36-pin TLS2158 provide optional shield-line pins located adjacent to the outer-head pins that, when bonded out, can be used to reduce the effects of mutual inductance. The optional flip-flop for write-data input can be enabled or disabled.