Technology

FS209

Rev0.3 Dec.31, 2004(LF)

APPLICATION NOTE

The Example of Typical Application Circuit

Fig 5 is the example of typical application circuit. The red, yellow, and black wires are the

input points of the motor system: red, the input of power supply; yellow, the output of FG;

The formula is:

C

ON

C

I

V

For example:

D1 is the reverse protection diode. As if the red and black wires reversely connect with the

power source, the current will flow through the ground via IC and coils L1 and L2 to power

supply. Under such kind of circumstances, the IC and coils are easy to be burned out.

Therefore, D1, the reverse protection diode, is necessary for the design. However, D1 will

also cause an extra voltage drop on the supply voltage.

C1 is a capacitor to reduce the ripple noise caused during the transient of the output stages.

The volume of the ripple noise depends on the coil impedance and characteristics.

Fig 5 Application Circuit

FS209

L1

D1

C1

B wire

R wire

NO

SO

Internal circuit of 2-phase DC motor

+Vcc

VCC

GND

+Vc

Y wire

Rc

FG

Output

L2