Complete Bias and White LED Power Supplies

for Small TFT Displays

2

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ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional

operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to

absolute maximum rating conditions for extended periods may affect device reliability.

LX, OUT to GND .....................................................-0.3V to +37V

CU1 to MAIN ............................................................-0.3V to +6V

CU2 to CU1 ..............................................................-0.3V to +6V

CU3 to CU2 ..............................................................-0.3V to +6V

CU3 to POS ............................................................-0.3V to +18V

CU3 to GND ...........................................................-0.3V to +18V

POS to GND ...........................................................-0.3V to +18V

CD1 to MAIN ..........................................................+0.3V to -12V

CD1 to GND .............................................................+0.3V to -6V

CD2 to CD1 ..............................................................+0.3V to -6V

NEG to CD2..............................................................+0.3V to -6V

NEG, CD2 to GND..................................................+0.3V to -12V

GND to PGND .......................................................-0.3V to +0.3V

°C)

24-Pin 4mm x 4mm Thin QFN

(derate 20.8mW/

°C above +70°C) .............................1667mW

Short-Circuit Duration (MAIN, POS, NEG)..................Continuous

Operating Temperature Range ...........................-40

°C to +85°C

Junction Temperature ......................................................+150

°C

Storage Temperature Range .............................-65

°C to +150°C

Lead Temperature (soldering, 10s) ................................ +300

°C

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

IN Operating Supply Range

2.7

5.5

V

IN Undervoltage-Lockout (UVLO)

Threshold

Rising edge, 30mV hysteresis

2.1

2.35

2.6

V

IN Quiescent Current

Switching

3

5

mA

0.4

1

IN Shutdown Current

1

µA

Thermal Shutdown

Rising temperature, 20°C hysteresis (typ)

+160

°C

MAIN CHARGE PUMP WITH LINEAR REGULATOR

Main Pump Efficiency

83

%

≥ 3.8V in 1.5x mode

9

20

Output Impedance

≥ 3.0V in 2.0x mode

7.5

20

Ω

Operating Frequency

200

250

300

kHz

Charge-pump pause threshold

5.2

5.5

5.7

V

3.75

3.85

3.95

V

3.8

3.9

4.0

V

Quiescent Current

(Charge Pumps Only)

0.87

1.30

mA

4.9

5.0

5.1

V

Discharge Switch Resistance

1

3

k

Ω

POS, NEG CHARGE PUMPS

Operating Frequency

12.0

15.6

19.5

kHz

Duty Cycle

50

%

POS Pump Efficiency

97

%

POS Output Voltage

13.9

14.7

15.3

V

POS Discharge Switch Resistance

3

6

k

Ω

NEG Pump Efficiency

97

%