Diodes AM4953 - Manual (Page 10)

Data Sheet
BTL Drive Single-phase Full-wave Fan Motor Driver AM4953
Apr. 2012 Rev. 1. 5 BCD Semiconductor Manufacturing Limited
10
Typical Application
FG
VCC
OUT2
GND
OUT1
CT
IN-
IN+
AM4953
HALL
R1
D1
C1
C2
L
RD
R2
HB
V
FG
V
RD
(Note 4)
(Note 2)
FG
VCC
OUT2
GND
OUT1
CT
IN-
IN+
AM4953
R3 C1
C2
L
AH921
R1
V
FG
D1
HB
RD
V
RD
R2
(Note 5)
(Note 4)
(Note 4)
Note 2: Adding D1 can protect the IC from destruction by reverse connection. If D1 is used, it is necessary to
insert a capacitor C1 to provide a regenerative current route. Similarly, if there is no nearby capacitor on the fan
power supply line, C1 will also be necessary to improve reliability. Its capacity should be larger than 2.2
µF.
Note 3: If the line between Hall sensor output and Hall sensor input of IC is long, the noise may occur in this line.
But it can be eliminated by adding a capacitor C3.
Note 4: Each of R1 and R2 is recommended to be 51k
Ω typical. R3 is recommended to be 2k and must be added
when V
CC
is larger than 20V.
Note 5: The package of AH921 is SOT-23-3. If it is packaged in TO-92S-3，please exchange IN- with IN+.
Figure 11. Typical Application of AM4953