TDA5147CH Datasheet, PDF (11/32 Pages) NXP Semiconductors – 12 V Voice Coil Motor VCM driver and spindle motor drive combination chip

Philips Semiconductors
12 V Voice Coil Motor (VCM) driver and
spindle motor drive combination chip
Preliminary specification
TDA5147CH
DISABLE VCM DRIVERS
With the V_PCNTL signal at 0.5V_CC the VCM drivers are
disabled while the rest of the circuits remain enabled.
A sleep mode is initiated when the spindle and VCM are
disabled (this places the TDA5147CH in its lowest power
setting).
ACTUATOR PARK
Retracting the actuator can be accomplished by driving
V_PCNTL LOW in conjunction with either the spindle turning
or a brake voltage has been applied. An adjustable retract
voltage of 1.2 V (max.) is applied between the V_CMN and
V_CMP outputs. The retract circuit obtains its retract current
from the spindle BEMF (pins SHPWR2 and SHPWR3).
The retract voltage is determined by two external resistors.
One end is connected to pin V_CMN and the other to ground.
The common point is connected to pin RET_ADJ (see Fig.8
for additional information).
The calculation of V_RETRACT is as follows:
V_RETRACT
=
V_BE
×


R-----1---R--+_{---1--R-----2--}
+
5----0-R----k2---Ω^---


V_BE = 0.65 V at 25 °C and ∆V_BE/∆T = −2 mV/°C, 50 kΩ
can vary by ±30%. It should be noted that R2 has to be less
than 10 kΩ.
Pin RET_ADJ can be pulled to ground by applying 0.7 V
(V_BE) on pin BRKTC. This is used to perform spindle brake
during power down.
When pin 35 (RET_ADJ) is pulled to ground, no regulation of
the V_CMN is taking place, but the V_CMP output is still kept
LOW. In that case, the SHPWR2 and SHPWR3 lines are
loaded with the VCM motor by means of an internal MOS
transistor.
handbook, full pagewidth
Vref
VIPWMH
LEVEL
CONVERTOR
SUM
UNITY
GAIN
LOW-PASS
VFLTOUT
VIPWML
LEVEL
CONVERTOR
32 : 1
ATTENUATION
MBH019
Fig.5 Block diagram of the VCM driver PWM filter.
Table 3 Booster, spindle drivers, comparator, decoder, amplifier and filter modes
FUNCTION
Spindle enable
Spindle disable
PORN LOW
Sleep
UPPER
BOOSTER
ON
ON
OFF
OFF
UPPER
DRIVERS
ON
ON
OFF
OFF
LOWER
DRIVERS
ON
ON
ON
ON
COMPARATOR
ON
ON
ON
ON
CONTROL
AMPLIFIER
ON
ON
OFF
OFF
1997 Jul 09
11