MAX26402/MAX26403

36V, 2.5A/3.5A, Fully Integrated Synchronous

Silent Switcher Buck Converters

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Analog Devices | 9

Pin Configurations

9

SUP

SUP

12

13

14

7

BST

EN

5

1

3

15

10

4

6

NC

NC

8

2

MAX26402

MAX26403

11

15 FC2QFN

3mm x 3mm

Pin Descriptions

PIN

NAME

FUNCTION

1

EN

High-Voltage-Tolerant, Active-High Digital Enable Input. Drive EN high to enable buck converter.

2, 8

NC

Not Connected

3, 7

SUP

Internal High-Side Supply Input. SUP provides power to the internal switch and LDO. Bypass SUP to

PGND with 0.1μF and 2.2μF ceramic capacitors. Place the 0.1μF capacitor as close to the SUP and

PGND pins as possible, followed by the 2.2μF capacitor.

4, 6

PGND

Power Ground

5

LX

Inductor Connection. Connect LX to the switched side of the inductor.

9

BST

Boost Flying Capacitor Connection for High-Side FET Gate Voltage. Connect a 0.1μF ceramic capacitor

between BST and LX.

10

GND

Quiet Analog Ground

11

BIAS

1.8V Internal BIAS Supply. Connect a minimum of 2.2μF ceramic capacitor from BIAS to PGND.

12

SPS

Spread-Spectrum Enable. Connect logic-high to enable spread spectrum of the internal oscillator or

logic-low to disable spread spectrum.

13

FB/OUT

Feedback/Output Sense Input. For the adjustable output-voltage IC, it acts as an output voltage

feedback input (FB). Connect an external resistor-divider between OUT, FB, and AGND to set the output

voltage.

For the fixed output-voltage IC, it acts as an output voltage sense pin (OUT). Connect OUT to the buck

output to sense the output voltage.

13

OUT

Output Sense Input. Connect OUT to the buck output to sense the output voltage.

14

PGOOD

Open-Drain, Power-Good Output. Connect PGOOD to BIAS or an external positive power supply with a

pull-up resistor.