LD7000
Spindle/VCM Controller and Pre-driver
DESCRIPTION
The LD7000 Servo and Spindle Predriver, a CMOS
monolithic integrated circuit housed in a 64-lead
TQFP package operates from +5 V and +12 V
supplies. It is designed to drive a voice coil actuator
and a 3-phase, Hall-sensorless motor with
external
power MOSFETs.
The device is intended for use in
12 V disk drive applications.
The actuator driver includes a saturation detector to
monitor the loop compensation amplifier for
saturation, an uncommitted opamp for input signal
conditioning, a voltage reference to provide a precise
voltage level for internal PWM buffers, and reduced
power dissipation.
The spindle driver includes a
碌P
controlled startup
ramp to replace the imprecise analog ramp, an
external PWM input to allow PWM frequencies
above the audible range, active pullup on the P
driver, adjustable N-channel slew rate, and improved
spindle brake performance.
A precision low voltage monitor circuit is also added
to monitor +5 V and +12 V supplies and to initiate
servo head retracts during voltage faults. All
functions are controlled by an SSI compatible
read/write serial port.
Three DC-DC converter circuits for 2.5V,3.3V,&-3/-
5Vsupplies are also available for digital chips and
MR bias negative supply.
FEATURES
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Small footprint 64 or 48 pin TQFP package
Spindle driver is PWM during run and start
Commutator is driven by a phase lock loop for
high jitter immunity
Adjustable slew rate to minimize stress in the
power MOSFETs
Microprocessor controlled spindle startup
Saturation detector to monitor loop
compensation amplifier status
Precision low voltage monitor circuitry for both
+5 V and +12 V supplies, LD7000 only
Dual level retract scheme includes adjustable
pulse mode, LD7000 only
Serial Port control
version 2.1
LD7000相關(guān)型號(hào)PDF文件下載
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