4.5V to 28V Input, Synchronous PWM Buck Controllers

for DDR Termination and Point-of-Load Applications

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.

V+, EN/HSD, EN, HSD to GND...............................-0.3V to +30V

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

VTT, REFIN, POK, OUT, FB, VL to GND...................-0.3V to +6V

LX to PGND ...............................................................-2V to +30V

BST to GND ............................................................-0.3V to +36V

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

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

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

°C)

16-Pin QSOP (derated 8.3mW/°C above +70

°C) ........667mW

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

V+ Input Voltage Range

VL not connected to V+

6

28

V

V+ Input Voltage Range

VL connected to V+

4.5

5.5

V

EN/HSD Input Voltage Range

MAX8553 enabled

1.5

28.0

V

EN Input Voltage Range

MAX8554 enabled

1.5

28.0

V

EN Input Current

23

µA

HSD Input Voltage Range

MAX8554 enabled

1.5

28.0

V

HSD Input Current

20

40

µA

REFIN Input Voltage Range

0

3.6

V

V+ Supply Current (MAX8553)

0.8

1.2

mA

V+ Supply Current (MAX8554)

0.62

0.90

mA

REFIN Supply Current

125

250

µA

EN/HSD Supply Current

510

µA

VL Supply Current

0.8

1.2

mA

V+ Shutdown Supply Current

EN/HSD = GND

3

5

µA

REFIN Shutdown Supply Current

EN/HSD = GND

1

µA

VL Shutdown Supply Current

5

12

µA

VL Undervoltage-Lockout Threshold

Rising edge, typical hysteresis = 40mV

4.05

4.25

4.40

V

VTT

VTT Input Bias Current

-0.15

0

µA

VTT Feedback Voltage Range

0

1.8

V

49.5

50

50.5

VTT Feedback Voltage Accuracy

49.5

50

50.5

FB Input Bias Current

-0.15

0

µA