Step-Down Converters

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.

IN, INP, OUT, D2, SHDN to GND ..........................-0.3V to +6.0V

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

LX Current (Note 1)...........................................................±2.25A

Output Short-Circuit Duration.....................................Continuous

10-Pin TDFN (derate 24.4mW/°C above +70°C) .......1951mW

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

Soldering Temperature (reflow) .......................................+260°C

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Input Voltage

2.6

5.5

V

Undervoltage-Lockout Threshold

2.20

2.35

2.55

V

No switching, D1 = D2 = GND

16

25

Quiescent Supply Current

Dropout

27

42

µA

0.1

1

Shutdown Supply Current

SHDN = GND

0.1

µA

Output Voltage Range

0.75

V

No load

-0.25

+0.75

+1.75

300mA load

-0.75

0

+0.75

600mA load

-1.5

-0.75

0

1200mA load, MAX1556

-2.75

-2.25

-1.25

(Note 2)

1200mA load, MAX1556A

-2.25

No load

-0.75

+2.25

300mA load

-1.5

+1.5

600mA load

-2.25

+0.50

Output Accuracy

(Note 2)

1200mA load, MAX1556

-4.0

-1.0

%

MAX1556/MAX1556A

1200

Maximum Output Current

MAX1557

600

mA

0.01

0.1

D1 = D2 = GND

MAX1556/MAX1557

0.01

OUT Bias Current

For preset output voltages

3

4.5

µA

No load

-0.50

+0.75

+1.75

300mA load

-1.2

0

+1.2

600mA load

-1.75

-0.75

+0.25

D1 = D2 = GND,

300mA (typ),

MAX1556/MAX1557

1200mA load, MAX1556 only

-3.25

-2.25

-1.25

No load

-1.25

+2.25

300mA load

-1.75

+1.50

600mA load

-2.75

+0.25

FB Threshold Accuracy

D1 = D2 = GND,

at 300mA (typ),

MAX1556/MAX1557

1200mA load, MAX1556 only

-4.25

-1.00

%

Note 1: LX has internal clamp diodes to GND and IN. Applications that forward bias these diodes should take care not to exceed

the IC’s package power-dissipation limits.