Data Sheet

BTL Drive Single-phase Full-wave Fan Motor Driver

AM4953

Aug. 2011

Rev. 1. 2

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

(Note 4)

(Note 2)

FG

VCC

OUT2

GND

OUT1

CT

IN-

IN+

AM4953

R3

C1

C2

L

AH921

R1

D1

HB

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

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