LX1688IPW datasheet(13/15 Pages) MICROSEMI

13 / 15 page

Microsemi

Integrated Products, Power Management

11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570

Page 13

 2001

Rev. 1.1a, 2003-03-21

RangeMAX™

LX1688

MULTIPLE LAMP CCFL CONTROLLER

I N T E GRA T ED

PR ODUC T S

APPLICATION INFORMATION ( C ONTINU E D)

Digital Dimming

The following oscilloscope waveforms are showing gate

signals of Master and slaves during digital dimming at 50%

and 5% duty cycle.

Figure 6- Gate signals during digital dimming with 50%

duty cycle CH2= AOUT(Master),

CH3=AOUT(Slave1), CH4=AOUT(Slave2)

Figure 7- Gate signals during digital dimming with 5% duty

cycle CH2= AOUT(Master), CH3=AOUT(Slave1),

CH4=AOUT(Slave2)

Output currents

Figure 8 shows the output current of master and slaves

during digital dimming with 5% duty cycle. The lamp currents

are operating in phase and frequency synchronization. This

prevents random interface between controllers and reduces

EMI.

Figure 8- Output current during

digital dimming with 5%

duty cycle R1= out(Master)

R2=Iout(Slave1)

R3=Iout(Slave2)

Lamp Current at 10mA/Div

LX1688IPW Datasheet(PDF) 13 Page - Microsemi Corporation