Fixed-Frequency, Full-Bridge CCFL

Inverter Controller

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7

NORMAL OPERATION

MAX8751 toc01

20

µs/div

A

B

A: VFB, 1V/div

B: LX1, 10V/div

C: LX2, 10V/div

D: IFB, 2V/div

C

D

MINIMUM BRIGHTNESS

MAX8751 toc02

2ms/div

A

B

A: COMP, 500mV/div

B: IFB, 2V/div

C: VFB, 1V/div

C

MINIMUM BRIGHTNESS

MAX8751 toc03

1ms/s

A

B

A: COMP, 500mV/div

B: IFB, 2V/div

C: VFB, 1V/div

C

Typical Operating Characteristics

50% BRIGHTNESS STARTUP WAVEFORM

MAX8751 toc04

2ms/div

A

B

A: COMP, 500mV/div

B: IFB, 2V/div

C: VFB, 1V/div

C

50% BRIGHTNESS DWPM WAVEFORM

MAX8751 toc05

1ms/div

A

B

A: COMP, 500mV/div

B: IFB, 2V/div

C: VFB, 1V/div

C

DPWM SOFT-START

MAX8751 toc06

100

µs/div

A

B

A: COMP, 1V/div

B: IFB, 1V/div

C: VFB, 1V/div

C