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LD7005
SPINDLE/VCM COMBO CHIP
Revision 1.4 LDIC CONFIDENTIAL Page 1
DESCRIPTION
LD7005 is a CMOS monolithic device that integrates spindle and VCM controllers as well as power stages into one
chip. The device operates from 3.3V or 5V power supply. LD7005 is designed for a small-form-factor hard disk
drive application.
A precision low voltage detection circuit monitors the power supply and initiates VCM retract at voltage fault
condition. A 3-line serial port interface with read back capability provides interface to the microprocessor.
The spindle driver features a transconductance amplifier, current sense amplifier, power output drivers, sequencer,
internal delay/masking logic, spindle brake circuit, FLL, and charge pump for locking the spindle to the
programmed rotational speed.
The VCM driver features a transconductance amplifier, differential input current sense amplifier, ramp load/unload
capability, and power output amplifier.
FEATURES
General
• Operates from single supply, 3.3V or 5V
• Small footprint 64-Pin TQFP package or Flip Chip
• Precision low voltage monitor circuitry for the power supply
• Master Power on Reset
• Serial Port Interface with Read-back capability
• Over-temperature protection/warning
• Shock sensor signal processing
• On-chip 1.8V, 2.5V and 3.3V Regulators
• Low power consumption, 9mA in normal run mode
Spindle Driver
• Commutator is driven by a FLL for high immunity to jitter
• Programmable 10-bit DAC
• Adjustable slew rate control
• External startup capability
• 1.0 Amp current capability with R
on
= 1 Ω
• Digital commutation delay and blanking
• Programmable delay from Bemf zero crossing
• External INDEX signal for spin lock
• Active spindle braking capability
VCM Driver
• 0.4 Amp current capability with R
on
= 1.5 Ω
• Programmable 14-bit DAC
• Ramp load/unload capability with 10-bit ADC
• Power-off retract with 9V charge-pump
• Programmable VCM current controlled by sense resistor
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LD7005
SPINDLE/VCM COMBO CHIP
Revision 1.4 LDIC CONFIDENTIAL Page 2
A
B
C
1
OTA
SEQ
Bemf
Comp
VSA
VSB
VSC
VSP
VST
ADVANCE
FLL
PRESCALER
CHP
UP DN
INDEX
PWM
Comp
MUX
BEMFO
SCOMP
Voltage Limiter
FLL
10 bit
DAC
Bemf
Comp
VSN
SYSCLK
BG
IREF
RREF
VREF
14 bit
DAC
POR
CRET
PORB
RTH
S/H
B
N
P
VVCC
VMP
VCMP
VCMN
VMN
ERRO
EA
ERRI
VREF
BA
SA
VCMS
S/H
A
M
U
X
10bit
ADC
ISO
9V
PUMP
CRET
RETO
3.3V
V3.3
VC3.3
2.5V
V2.5
VC2.5
1.8V
V1.8
VC1.8
VREF
VREF
XIN
SHOCKIN
XOUT
F40
3 bit
DAC
SHOCKB
SERIAL
PORT
SDEN
SCLK
SDATA
CLK
Comp
DGND
TMON
OTSD
OTW
AGND
DVCC
AVCC
RGND
RVCC
DACO
DRET
Fig. 1 – LD7005 Block Diagram
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