HA13568AT データシートの表示（PDF） - Hitachi -> Renesas Electronics

部品番号

コンポーネント説明

メーカー

HA13568AT

CD-ROM Combo Driver

Hitachi -> Renesas Electronics 

HA13568AT

External Components (cont)

Reccomended Reccomended

Parts No. Value

Range

Purpose

Note

Ct1

150 pF

≥ 120 pF

Time constant for CLK oscillation. Use a

3

capacitor with good temperature characteristics.

Ct2

0.033 µF

Time constant for start-up oscillation. Use a

4

capacitor with good temperature characteristics.

Ct3

470 pF

≥ 390 pF

PWM carrier oscillation time constant

5

Q1

Transistor for voltage regulator

Note:

1. The output current maximum value Iospnmax of SPN driver is controlled according to the

following equation. However, Vspncl is the current limiter reference voltage. (See the electrical

characteristics)

Iospnmax =

Vspncl

Rnf

2. The maximum duty Dmax of SLD driver output is controlled according to the following equation.

Dmax =

Vrt

Vhct3 − Vlct3

Rt2

Rt

−

Vlct3

Vrt

× 100 (%)

However,

Rt = Rt1 + Rt2,

Rt2

Rt

≥

Vlct3

Vrt

Where, Vrt : RT pin voltage (See the electrical characteristics)

Vlct3 : CT3 pin low voltage (≈ 1.3 V)

Vhct3 : CT3 pin high voltage (≈ 3.3 V)

Since Vrt ≈ Vhct3, Dmax is not limited at 100% when Rt1 = 0 Ω.

3. The CLK oscillation frequency is determined by the following equation.

fclk

=

8

Ct1

Vrt

Rt ∆Vct1

Where, Vrt : RT pin voltage (See the electrical characteristics)

∆Vct1 : CT1 pin voltage amplitude (≈ 1 V)

4. The Ct2 for start-up oscillation is determined by the following equation.

Tc2 = 1

6

J

P Kt Ispnmax

Ct2 =

Tc2 Vrt

8 Rt (Vhct2 − Vlct2)

Where, J

: Spindle motor inertia (kg · cm · S2)

P : Number of spindle motor poles (Total number of S poles and N poles)

Kt : Spindle motor torque constant (kg · cm / A)

Vhct2 : CT2 pin high voltage (≈ 3.3 V)

Vlct2 : CT2 pin low voltage (≈ 1.3 V)

12

Share Link: