AN8814SB Datasheet, PDF (5/5 Pages) Panasonic Semiconductor – 4-channel driver IC for optical disk drive

ICs for Compact Disc/CD-ROM Player
s Application Circuit Example
V_REF
V₄ V₃
V₂
V₁
PV_CC1
AN8814SB
RL1
RL2
SV_CC
PV_CC2
RL4
RL3
When the AN8814SB is use, take into account the following cautions and follow the power dissipation characteristic curve.
1. Load current I_P1 flowing into load RL1, RL2 is supplied through pin 20.
I_P1
=
|
V₁₈ −V₁₇
R_L1
|
+
| V₁₆ −V₁₅ |
R_L2
2. Load current I_P2 flowing into load RL3, RL4 is supplied through pin 9.
I_P2
=
|
V₁₄ −V₁₃
R_L3
|
+
| V₁₂ −V₁₁ |
R_L4
3. Dissipation increase (∆P_D) inside the IC (power output stage) caused by loads RL1, RL2, RL3 and RL4 is as follows:
∆P_D = (PV_CC1 − | V₁₈ −V₁₇ |) ×
| V₁₈ −V₁₇ |
R_L1
+
(PV_CC1
−
|
V₁₆
−
V₁₅
|)
+
|
V₁₆ −V₁₅
R_L2
|
= (PV_CC2 − | V₁₄ −V₁₃ |) ×
| V₁₄ −V₁₃ |
R_L3
+
(PV_CC2
−
|
V₁₂
−
V₁₁
|)
×
|
V₁₂ −V₁₁
R_L4
|
4. Dissipation increase (∆P_S) inside the IC (signal block supplied from pin 7) caused by loads RL1, RL2, RL3 and RL4
comes roughly as follows:
∆P_S
=
3
×
{
V₁
R₁
×
(2
×
SV_CC +
|
V₁₈
−V₁₇
|)
+
V₂
R₂
×
(2
×
SV_CC
+
|
V₁₆
−V₁₅
|)
+
V₃
R₃
×
(2
×
SV_CC
+
|
V₁₄
−V₁₃
|)
+
V₄
R₄
× (2 × SV_CC + | V₁₂ −V₁₁ |)}
5. Dissipation increase in a driver operating mode is ∆P_D + ∆P_S .
6. Allowable power dissipation without load (P_D1) can be found as follows:
P_D1 = SV_CC × I_SVCC + PV_CC1 × I_PVCC1 + PV_CC2 × I_PVCC2
7. Allowable power dissipation in a load operating mode (P_D) comes roughly as follows:
P_D = P_D1 + ∆P_D + ∆P_S
5