SD1579 Silan Microelectronics, SD1579 Datasheet - Page 6

• Manufacturer Part Number: SD1579
• Description: Hall IC Fan Motor Driver
• Manufacturer: Silan Microelectronics

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APPLICATION INFORMATION
1.
2.
3.
4.
HANGZHOU SILAN MICROELECTRONICS CO.,LTD
Http://www.silan.com.cn
Back electromotive force causes regenerated current to V
a capacitor between power supply and GND for routing regenerated current; In order to reduce the output
DO and DOB side effects of induced electromotive force, need to increase a resistance-capacitance
network at the output; in a typical application circuit diagram, R1 and R2 is typically 56 ohms; C1, C2 and
C3 is typically 2.2uF; The value of R and C must match the actual coil;
Figure 2 is the normal working state, the current compose I
+ V
its maximum power dissipation value dule to change of power supply voltage V
SD1579 has built-in reverse protection diodes, so D1 is no need; If you increase the D1 can better protect
the chips, as shown in Figure 3; it should be noted that care should to taken to the two coils current when
power voltage reversed, if 2*Vo * I
Add a diode to coils can better protect the chip and the fans at reverse voltage state, as shown in Figure 4;
o
* I
load
Fig.2 Normal working state
, Where Vo is the output voltage when DO or DOB turn on; It is need to be careful not to exceed
load
Figure 4 Add a diode to coils
> IC's power consumption, it may cause damage to IC;
DD
CC
line, therefore take a measure such as placing
and I
Fig.3 Reverse voltage state
load
, power dissipation PC = V
DD
and the coil current I
REV:1.0
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2009.11.11
DD
load
* I
CC
.