HA13561F
11. The frequency response of VCM driver maybe have a gain peaking because of the resonation of
the motor coil impedance. If you want to tune up for this characteristics, you can reduce the
peaking by additional snubber circuit RX and CX as follows.
BTL Driver
+
–
R3
1/2 VPS
– R3
+
N
RX Coil
CX
RS
RS
P
Figure 1 VCM Driver Block Diagram
20
10
IO
0
(dB)
–10
–20
Normal
CX = 0.22µF
RX = 560Ω
100
1k
10k
100k
Frequency (Hz)
(for example) RL = 14.7 Ω, RS = 1 Ω, L = 1.7 mH, Gain = L
12. The retract current Iret is determined by following equation.
Iret = Vretpow – Vsat(Qret) – VF(D1) – VsatVL
R108 + Rs + RL
(28)
where, Vretpow: Applied voltage on pin 78 [V]
Vsat (Qret): Saturation voltage of Qret [V]
VF (D1): Foward voltage of D1 [V]
17