FAN8903 View Datasheet(PDF) - Fairchild Semiconductor

Part Name

Description

Manufacturer

FAN8903

Power Window Motor Control IC

Fairchild Semiconductor 

FAN8903(KA3903)

The position of the sensor must be set adequately upper part of the window. When the obstacle between the window glass and

the upper limit are inserted, the light sensor TR is turned off. The sensor have a two function;

- End position switch,

- Issuing the OCP signal.

Q2 is used to make the F/C pin low, and Q4 enables to turn-on Q6 to issue the OCP signal.

As soon as Q2 is turned on, V2 changes from the equation mentioned in 6.2 paragraph to the below equation.

V2 = Vcom × [R10 // (Rntc + Rt)] ⁄ [R10 // (Rntc + Rt) + R5]

and OP-amp output become low level. Therefore the HBP logic stops the motor and reverses the direction of the motor.

You can adjust the delay time by changing the value of the resistor, R10. The added part works only when Q5 is on-state. In

other words, when the window glass is moving upward, the added part operates. Q3 is also turned on and holds the F/C pin low

level.

Light

sense

Start key

Added part

R4

KSR1012

Q2 Q3

Motor

(+)

FAN8903

VCC

V1

5

C3

+

−

COMP

2

KSR2007

Q4

KSC945

Q6

R10

NTC

Rt

6

C2

OP-amp

Q5

Pin #8

7

−

Vro

+

R3

−

Vref

0.8V +

RS

OCP

Output Stage

The output stage is a darlington TR with an integrated zener diode, and designed at a pulse current of a approx. 0.4A. The

zener diode limits the inductive switch-off voltage. The relay coil has a typical resistances of 200Ω, and the zener diode volt-

age is 18.6V.

With the circuitry of this type, the FAN8903 can sustain 24V for one minute (or continuously) and load dump

(70V, 0.2sec) condition without a damage.

10

Share Link: