Data Brief

For further information contact your local STMicroelectronics sales office.

July 2006

Rev 1

1/3

3

L6440

4-Channel ultra low power GMR-TMR preamplifier

for HDD applications

Feature summary

and -2.1V, ±6%

and perpendicular write heads

(RMR=250Ohm, Ibias =400µA, NF<2dB)

600Mb/s measured with single head 100%

Write mode duty cycle, 127b PRBS,

Iw = 40mA, OSC = 100mA (0-pk),

OSD = 500ps (PW50), with Heater off

power output

Sense architecture

3.3V CMOS compatible

Description

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.

The part is further comprehensive of an extensive

analog/digital measurement scheme for the read,

write, heater heads and die temperature, of an

extensive fault detection and reporting scheme,

thermal asperity detection and correction, write

degauss function.

Order code

Flip Chip (Bumped die)

Part number

Package

Operating temp. range

L6440

Flip Chip (Bumped die)

-25°C to +85°C

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