SR1730ABA - Texas Instruments - Datasheet.Directory

SR1730ABA

+5/-5V 4/8-CHANNE L

MR READ/WRITE DEVICE

May, 2000

DESCRIPTION

The TI SR1730ABA is a BiCMOS monolithic

integrated circuit designed for use with four-terminal

Magneto-Resistive recording heads. The reader

architecture is MR current bias/voltage sense and

will support a user data rate of up to 500 Mbits/sec.

A read/write c ap abl e s eri al p or t is pr ov id ed t o e nable

the implementation of on-chip MR bias and Write

current DACs. The device provides a write driver,

low-noise read amplifier, serial port controlled head

selection, write current, MR read bias current and

read and wr ite fault detecti on circuitr y for u p to eight

channels. The device requires +5V and -5V and

comes in die form or in a 48-pin TQFP package.

FEATURES

•

••

• +5V ±

±±

±10%, -5V ±

±±

±10% supplies

•

••

• Designed for four-terminal MR heads with

minimum external components

•

••

• DC blocking capacitors int egrat ed on chip

•

••

• Truly differential current bias/voltage sense

MR read Amp

•

••

• MR head bias current range = 2.1 – 9.6 mA

(5-bit)

•

••

• MR read gain = 93 V/V and 137 V/V @ 45 Ω

ΩΩ

Ω

•

••

• MR read input noise = .70 nV/√

√√

√Hz @ 45 Ω

ΩΩ

Ω

•

••

• Read bandwidth = 300 MHz

•

••

• Differential PECL write data input, 3V logic

compatible

•

••

• Head voltage swing = 12 Vp-p

•

••

• Write current range = 15.8 - 63 mA (5-bit)

•

••

• Write current rise/fall time = 0.8 ns (Lh = 80

nH, Rh = 11 Ω,

Ω, Ω,

Ω, 50% boost)

•

••

• Servo bank write capability

•

••

• Read and write unsafe detection

•

••

• Thermal asperity detection and fast recovery

•

••

• Power supply fault protection

•

••

• Serial port controls head selection, write

current, MR read bias current

5/18/00