Low-Cost CCFL Backlight Controller

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5

ELECTRICAL CHARACTERISTICS (continued)

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

80

120

Current-Limit Threshold

LX1 - PGND, LX2 - PGND

(Adjustable)

370

430

mV

Zero-Current Crossing Threshold

LX1 - GND, LX2 - GND

112

mV

Current-Limit Leading Edge

Blanking

240

460

ns

IFB Input Voltage Range

-2

+2

V

IFB Regulation Point

770

810

mV

-2

+2

IFB Input Bias Current

-150

µA

IFB Lamp-Out Threshold

560

640

mV

IFB to COMP Transconductance

60

160

µS

COMP Output Impedance

718

M

Ω

ISEC Overcurrent Threshold

1.15

1.28

V

VFB Overvoltage Threshold

2.2

2.4

V

DPWM Chopping Frequency

200

218

Hz

DPWM Input Low Voltage

0.8

V

DPWM Input High Voltage

2.1

V

DPWM Output Low Resistance

2.4

k

Ω

DPWM Output High Resistance

2.4

k

Ω

SYNC Input Low Voltage

0.8

V

SYNC Input High Voltage

2.1

V

SYNC Input Bias Current

-0.3

+0.3

µA

SYNC Input Frequency Range

10

50

kHz

CNTL Minimum Duty-Cycle

Threshold

0.20

0.26

V

CNTL Maximum Duty-Cycle

Threshold

1.9

2.1

V

SHDN Input Low Voltage

0.8

V

SHDN Input High Voltage

2.1

V

FREQ Dual-Mode Input High

Level

0.35

V

TFLT Trip Threshold

3.95

4.20

V

Note 1: Specifications to -40°C are guaranteed by design based on final characterization results.