LDIC LD7015 Datasheet
LD7015
SPINDLE/VCM COMBO CHIP
Revision 1.5 Page 1
SPINDLE/VCM SPECIFICATION
1. DESCRIPTION
LD7015 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 power supply. LD7015 is designed for a small-form-factor hard disk drive
applications.
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.
2. FEATURES
2.1. General
• Operates from single supply, 3.3V
• 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 -3V Regulators
• Low power consumption, 9mA in normal run mode
2.2. Spindle Driver
• Commutator is driven by a FLL for high immunity to jitter
• Programmable 10-bit DAC
• Adjustable slew rate control
• External startup capability
• 0.4 Amp current capability with R
on
= 1.4 Ω
• Digital commutation delay and blanking
• Programmable delay from Bemf zero crossing
• External INDEX signal for spin lock
• Active spindle braking capability
2.3. VCM Driver
• 0.4 Amp current capability with Ron = 2.2 Ω
• Programmable 14-bit DAC
• Ramp load/unload capability with 10-bit ADC
• Programmable VCM current controlled by sense resistor
LD7015
SPINDLE/VCM COMBO CHIP
Revision 1.5 Page 2
A
B
C
1
OTA
SEQ
Bemf
Comp
SPA
SPB
SPC
SPP
SPT
ADVANCE
FLL
PRESCALER
CHP
UP DN
INDEX
PWM
Comp
MUX
BEMFO
SCOMP
Voltage Limiter
FLL
10 bit
DAC
SA
SPN
SYSCLK
RREF
VREF
14 bit
DAC
AVCC
S/H
B
VVCC
VMP
VCMP
VCMN
VGND
VEO
VCOMP
VCMS
S/H
A
M
U
X
10bit
ADC
VSO
CRET
VREF
XIN
SHOCKIN
XOUT
F40
SHOCKB
SDEN
SCLK
SDATA
CLK
VREF
3 bit
DAC
Comp
SERIAL
PORT
RETO
DRET
RVCC
RGND
N
P
EA
SA
BA
TMON
OTSD
OTW
VDAC
AGND
DGND
DVCC
VBO
SSO
SCMD
IREF
BG
CPOR
PORB
RTH
V25
POR
RETR
VC25
2.5V
1.8V
-3V
V18
VC18
MCMD
MSNS
MCOMP
FIG. 1 - BLOCK DIAGRAM OF SPINDLE/VCM
Loading...