4-channel Ultra Low Power Gmr-tmr Preamplifier For Hdd Applications

The L6440 is a BICMOS Silicon Germanium monolithic integrated circuit differential preamplifier for Ultra Low Power Hard Disk Drive applications. This part is specially designed to have minimum dissipation in all the modes of operation (Sleep <200mW, Read <60mW, Write <200mW) and very fast Sleep to Read recovery time (S2R <500ns). It is designed for use with 4-terminal Giant Magneto Resistance / Tunnel Magneto Resistance read and Perpendicular write heads. In read mode, the device consists of a fully Differential Amplifier offering: current or voltage bias, voltage-sense input, programmable input impedance, a wide-range read gain, low-noise and high-bandwidth. In write mode, it includes fast current switching differential write drivers, which support data rates up to 600 Mb/s, overshoot amplitude and duration programmability. In all the modes of operations Fly Height Control circuit is available. This circuit delivers an accurate programmable voltage or power to a resistive element near the write head to match write current induced heating and subsequent expansion or protrusion of the pole tip which effect the media spacing. By STMicroelectronics