LD3511-XX
4, 6, up to 8 Channel
+5V, +8V GMR Head Preamplifier
Samples Available
version 1.0
DESCRIPTION
The LD3511-XX is a high performance
BiCMOS, read/write preamplifier IC, designed
for use with 4-terminal GMR recording heads.
The device provides a low noise GMR head
amplifier, DC bias current control for GMR
head, 8V thin film write driver, write current
control to the write current drivers, thermal
asperity (TA) detection and correction. Fast
recovery mode can be also programmed to put
the chip faster in read mode from any other
existing modes. The device is programmable
for read gain, write overshoot and undershoot,
fast recovery, GMR resistance measurement
and thermal asperity threshold level. The
device features multiple channel write. Half or
all of the heads can be simultaneously selected
in the servo write mode. Features and
thresholds are controlled through a 3-line serial
interface with readback. This product requires a
5V & 8V supplies. This device also provides
PLR circuit, and on-chip temperature monitor
function. This device is available in flip-chip or
TSSOP 30 & 38-Pin packages.
FEATURES
• Current Bias/Current Sense Architecture
• Operates from 5V and 8V supply
• 3-line serial interface with readback (3.3V
CMOS compatible)
• Power fault protection
• Power management modes
• On-chip temperature monitor
• External reference resistor (2Kohm)
• Head unsafe fault detection for both read
and write
• Unselected read/write heads at GND
potential
• Fast recovery mode
• 300MHz Read Bandwidth
• One side grounded input, fully differential
output
• Read frequency boost
• Programmable GMR resistance
measurement mode (5-bits)
• Programmable GMR Pinned Layer Reset
(PLR) pulse circuit
• GMR bias current range 2-9.75 mA (5-bits)
• GMR resistor range = 25 to 75 Ω
• Programmable read gain = 225 V/V or 300
V/V
• Input equivalent noise TBD nV√Hz @ Rmr
= 45Ω
• TA detection & programmable
compensation
• 0.75ns Write rise/fall time (L=90 nH/40
mA)
• Write current range = 15-60 mA (5-bits)
• Programmable write current overshoot (4-
bits)
• Programmable write current undershoot (3-
bit)
• 200ns Write/Read switching time
• Servo write (half bank or all bank write)
• Integrated Reader low freq. blocking
Capacitor