3A, Low-Voltage, Step-Down Regulator with

Synchronous Rectification and Internal Switches

2

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ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

+25°C.)

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.

IN to PGND .....................................................................0V to 6V

PGND to GND.....................................................................±0.5V

LX to PGND.................................................................-0.5V to 6V

SHDN to GND .............................................................-0.3V to 6V

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

on 1 sq. inch of one ounce copper)

20-Pin SSOP (derate 22mW/°C above +70°C) ................1.3W

Operating Temperature Range ...........................-40°C to +85°C

Storage Temperature Range .............................-65°C to +150°C

Lead Temperature (soldering, 10sec) .............................+300°C

FBSEL = REF

FBSEL = GND

(Note 1)

SHDN = GND

FBSEL = GND or REF (Note 1)

Does not include switching losses

CONDITIONS

V

0.8

SHDN Input Low Voltage

µA

-1

0.03

1

SHDN Input Current

2

%

1

AC Output Load Regulation

µs

0.85

1.00

1.15

Off-Time Default Period

µs

0.5

4

Off-Time Adjustment Range

kHz

500

Error-Amplifier Gain Bandwidth

nA

-25

25

FB Input Bias Current

V

4.1

4.2

4.3

Undervoltage Lockout Threshold

°C

145

Thermal Shutdown Threshold

µA

0.5

10

Shutdown Supply Current

µA

400

525

No-Load Supply Current

A

1

1.25

1.5

Idle Mode Threshold (Note 2)

2.49

2.525

2.550

V

3.296

3.330

3.366

V

4.5

5.5

Input Voltage Range

Output Voltage

kHz

350

Maximum Switching Frequency

m

Ω

60

100

NMOS Switch On-Resistance

m

Ω

55

100

PMOS Switch On-Resistance

A

3.65

4.65

Current-Limit Threshold

1.089

1.100

1.110

V

3.80

Output Adjustment Range

V

1.089

1.100

1.110

Reference Output Voltage

mV

1

Reference Load Regulation

UNITS

MIN

TYP

MAX

PARAMETER

FBSEL = unconnected

FBSEL = GND or REF

V

2

SHDN Input High Voltage

µA

±20

LX Leakage Current