2006. 4. 20

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KIB3402F

Revision No : 0

2. Using a PWM Signal to CTL pin.

With the PWM signal applied to the CTL pin, the KIB3402F is turned

on or off by the signal. Typical frequency range of the PWM signal is

15kHz to 30kHz.

The switching waveforms of the CTL pin PWM

control are shown in Figure 7(A) and 7(B)

Figure 7. Using a PWM Signal to CTL pin.

3. Using a DC Voltage to FB pin.

The dimming control using a DC control voltage to FB pin of the

KIB3402F is shown in Figure. The LED current can be varied

applying a DC voltage to the FB pin. The voltage can come from a

filtered PWM signal. It can be used to replace the variable DC

Voltage source in dimming control.

4. Using a Logic Signal to FB pin.

For applications that need to adjust the LED current in discret steps,

a logic signal can be used as shown in Figure 9.

Figure6. Using a DC Signal to CTL pin.

0

GND

SW

L1

C1

C2

KIB3402F

D1

DC

CTL

FB

OVD

LED1

LED2

LED3

LED4

1

2

4

3

6

5

1 F

µ

4.7 H~10 H

µ

µ

1 F

µ

0

GND

SW

L1

C1

C2

KIB3402F

D1

PWM

CTL

FB

OVD

LED1

LED2

LED3

LED4

1

2

4

3

6

5

1 F

µ

4.7 H~10 H

µ

µ

1 F

µ

CTL

Vsw

V

5V/Div

2V/Div

(A) 1kHz (2ms/Div)

CTL

Vsw

V

5V/Div

2V/Div

(A) 1kHz (2ms/Div)

0

Figure8. Using DC Voltage to FB pin.

0

GND

SW

L1

C1

C2

R1

R2

KIB3402F

D1

CTL

FB

DC

OVD

LED1

LED2

LED3

LED4

0

0

1

2

4

3

6

5

1 F

µ

1 F

µ

0

Figure9. Using a Logic Signal to FB pin.

GND

SW

L1

1uF

C1

1uF

C2

dim

R

LOGIC

KTK5132V

KIB3402F

D1

CTL

FB

OVD

LED1

LED2

LED3

LED4

1

2

4

3

6

5