High-Speed Step-Down Controller with

Accurate Current Limit for Notebook Computers

2

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ABSOLUTE MAXIMUM RATINGS

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.

V+ to GND ..............................................................-0.3V to +28V

OUT, PGOOD, SHDN to GND ..................................-0.3V to +6V

FB, ILIM, LATCH, OVP, REF, SKIP,

BST to GND ............................................................-0.3V to +34V

CS to GND.................................................................-6V to +30V

DH to LX .....................................................-0.3V to (BST + 0.3V)

LX to BST..................................................................-6V to +0.3V

REF Short Circuit to GND ...........................................Continuous

20-Pin QSOP (derate 9.1mW/

°C above +70°C)...........727mW

above +70°C).................................................................1.60W

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

ELECTRICAL CHARACTERISTICS

°C to +85°C, unless otherwise noted. Typical values are at

°C.)

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Battery voltage, V+

2

28

Input Voltage Range

4.5

5.5

V

FB = OUT

0.99

1.01

FB = GND

2.475

2.5

2.525

Error Comparator Threshold

(DC Output Voltage Accuracy)

(Note 1)

V+ = 4.5V to 28V,

1.782

1.8

1.818

V

Load Regulation Error

9

mV

Line Regulation Error

5

mV

FB Input Bias Current

-0.1

+0.1

µA

Output Adjustment Range

1

5.5

V

FB = GND

90

190

350

OUT Input Resistance

70

145

270

k

Ω

Soft-Start Ramp Time

Rising edge of SHDN to full current limit

1.7

ms

TON = GND (600kHz)

140

160

180

TON = REF (450kHz)

175

200

225

TON = unconnected (300kHz)

260

290

320

On-Time

V+ = 24V,

(Note 2)

380

425

470

ns

Minimum Off-Time

(Note 2)

400

500

ns

FB forced above the regulation point

550

800

µA

FB forced above the regulation point

<1

5

µA

Quiescent Supply Current (V+)

25

40

µA

SHDN = GND

<1

5

µA

SHDN = GND

<1

5

µA

Shutdown Supply Current (V+)

<1

5

µA

Reference Voltage

1.98

2.00

2.02

V

Reference Load Regulation

0.01

V