NJU7327

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I APPLICATION NOTE

The NJU7327 is a single-phase DC brushless motor driver IC in small VSP-10 package.

With minimal external components, it can drive up to 200mA of motor current for small fan application.

[Application Circuit Example]

IN+

IN-

VDD

LD

VSS

OUTB

OUTA

FG

Motor

Hall

element

C2

R1

R3

R2

FG out

NJU7327

V+

GND

C1

D1

[Design Notes]

Above application example is designed for 12V operation with motor current of 200mA. It uses the following

components:

Hall elements: HW101A (AKE)

1. Selection of C1 and D1:

C1 is used for a noise reduction purpose. A typical value is 0.1uF.

Optimize the value in actual operating conditions if necessary. D1 is a diode for protection against reverse voltage

supply. Silicon rectifier diode (WO3C, 10D1 and equivalent) is appropriate.

2. Lock Protection Function (Design of C2 value):

Lock Protection Function, consists of Motor Lock Detection and Auto Resume Function, is a safety feature to protect

a motor and a driver circuit from fatal destruction in case of motor halt.

Motor Lock Detection detects motor halt due to irregular load conditions and then cuts motor driving current f or

safety operation. A value of C2 determines Lock detection time () and Auto Resume Time (Toff).