HA13614FH Datasheet, PDF (19/26 Pages) Hitachi Semiconductor – Combo (Spindle & VCM) Driver

HA13614FH
8. The delay time of the power monitor for start up is as follows.
tpor = 140 ⋅ C105
[ms]
(15)
9. The cut off frequency fcpwm of the filter for current control input of the spindle motor is as
follows.
fcpwm
=
2π
×
1
20k
⋅
C103
[Hz]
(16)
10. To get the maximum driving efficiency for spindle motor, the capacitor C101, C102 should be
chosen as following equation.
C101 = 0.8 ⋅ C102
(17-1)
C102 =
tan(π/6)
2π ⋅ 13k
⋅
1
fbemf
[F]
(17-2)
fbemf : Back EMF frequency at standard rotation speed of the spindle motor [Hz]
where, please set the value of C101, C102 so that C101 < C102 can be kept including the
accuracy of the absolute value to assure the stability of motor starting and speed lock state.
11. To stabilize output voltage od retract driver, the capacitor C115 should be chosen as following
equation. Please chose same values for C115.
C115 =
3 ⋅ 10^−6
2π ⋅ (R105 // R106)
[F]
(18)
12. Time t_BRKDLY of the delayed brake of V, W phase for retract is determined by resistor R109 and
capacitor C112, C116 as following equation.
t_BRKDLY = −
C116 ⋅ R109
1 + ^C116
⋅ ln
1−
Vthb
V_BRK0
⋅
1+
C116
C112
[s]
C112
(19)
where, Vthb : Threshold voltage that output MOS transistor of spindle motor driver is
operated.
V_BRK0 = Vpss – 0.7 [V]
Vpss : +12 V power supply for spindle motor driver
and, please select capacitor C112 and C116 that the ratio of C112/C116 is more than 3 times,
because the last voltage of BRK and BRKDLY terminals falls if the value of C116 is big for C112,
and effect of brake goes down.
19