HA13571FR Datasheet, PDF (12/22 Pages) Hitachi Semiconductor – Combo (Spindle & VCM) Driver for HDD

HA13571FR
External Components (cont)
Parts No.
Reccomended
Value
Purpose
Cf
—
Snubber for VCM Driver
D1 to D3
TBD
Power rectification for Retract driver
SBD1 *
HRU0302A
Prevent of malfunction for Retract driver
Note:
Retract circuit sometime will be malfunctioning by means of negative voltage on the terminal
VCMREF (pin 52) in the following sequence.
If you want to countermeasure this, you need to avoid the following sequence or to attach the
Schottky Barrier Diode (SBD1) between terminal VCMREF and GND. (see figure 2)
1. Spindle motor driver is active and VCM driver is disable by (VPCNTL = Middle).
2. Power supply goes to low level after above condition 1 and retract circuit becomes active by
(POR = L).
C117
0.47µF
37 VREFOUT
VCMREF 52
C133
4.7µF
Figure 2
C120 SBD1
0.01µF HRU0302A
12